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| There are many types of cancer. Severity of symptoms depends on the site and character of the malignancy and whether there is metastasis. A definitive diagnosis usually requires the ]. Once diagnosed, cancer is usually treated with a combination of], ] and ]. As research develops, treatments are becoming more specific for the type of cancer pathology. Drugs that target specific cancers already exist for several types of cancer. If untreated, cancers may eventually cause illness and , chemicals or physical agents that cause cancer, which are called ], or by certain viruses that can insert their DNA into the human genome. Mutations occur sphuyr* If a player kicks an opponent | |||
| {{otheruses}} | |||
| * If a player ytyy* If a player kicks an opponent | |||
| {{Infobox_Disease | | |||
| * If a player touches the ball with his hands (other than the goal keeper in his own penalty area) | |||
| Name = Cancer | | |||
| * If a player is caught ] | |||
| Image = Normal cancer cell division from NIH.png | | |||
| * If a player kicks an opponent | |||
| Caption = When normal cells are damaged beyond repair, they are eliminated by ]. Cancer cells avoid apoptosis and continue to multiply in an unregulated manner | | |||
| * If a player touches the ball with his hands (other than the goal keeper in his own penalty area) | |||
| DiseasesDB = 28843 | | |||
| * If a player is caught ] | |||
| ICD10 = | | |||
| area) | |||
| ICD9 = | | |||
| * If a player is caught ] | |||
| ICDO = | | |||
| ontaneously, and may be passed down from one cell generation to the next as a result of mutations within ]s. However, some ] also appear to work through non-mutagenic pathways that affect the level of ] of certain genes without causing genetic mutation. | |||
| OMIM = | | |||
| MedlinePlus = 001289 | | |||
| eMedicineSubj = | | |||
| eMedicineTopic = | | |||
| MeshName = Cancer | | |||
| MeshNumber = C04 | | |||
| }} | |||
| '''Cancer''' is a class of ]s or disorders characterized by uncontrolled ] of ] and the ability of these to spread, either by direct growth into adjacent tissue through ''invasion'', or by implantation into distant sites by '']'' (where cancer cells are transported through the ] or ]). Cancer may affect people at all ages, but risk tends to increase with age. It is one of the principal ] in ]. | |||
| There are many types of cancer. Severity of symptoms depends on the site and character of the malignancy and whether there is metastasis. A definitive diagnosis usually requires the ] examination of tissue by a ]. This tissue is obtained by ] or ]. Most cancers can be treated and some cured, depending on the specific type, location, and ]. Once diagnosed, cancer is usually treated with a combination of ], ] and ]. As research develops, treatments are becoming more specific for the type of cancer pathology. Drugs that target specific cancers already exist for several types of cancer. If untreated, cancers may eventually cause illness and ], though this is not always the case. | |||
| The unregulated growth that characterizes cancer is caused by damage to ], resulting in ]s to ]s that encode for ]s controlling cell division. Many mutation events may be required to transform a normal cell into a malignant cell. These mutations can be caused by radiation, chemicals or physical agents that cause cancer, which are called ], or by certain viruses that can insert their DNA into the human genome. Mutations occur spontaneously, and may be passed down from one cell generation to the next as a result of mutations within ]s. However, some ] also appear to work through non-mutagenic pathways that affect the level of ] of certain genes without causing genetic mutation. | |||
| Many forms of cancer are associated with exposure to ]s such as ], ], ], and certain ]es. Some risk factors can be avoided or reduced. | Many forms of cancer are associated with exposure to ]s such as ], ], ], and certain ]es. Some risk factors can be avoided or reduced. | ||
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| With the widespread use of the microscope in the 18th century, it was discovered that the 'cancer poison' spread from the primary tumor through the lymph nodes to other sites ("]"). The use of ] to treat cancer had poor results due to problems with hygiene. The renowned Scottish surgeon ] saw only 2 breast tumor patients out of 60 surviving surgery for two years. In the 19th century, ] improved surgical hygiene and as the survival statistics went up, surgical removal of the tumor became the primary treatment for cancer. With the exception of ] who in the late 1800s felt that the rate of cure after surgery had been higher ''before'' asepsis (and who injected bacteria into tumors with mixed results), cancer treatment became dependent on the individual art of the surgeon at removing a tumor. During the same period, the idea that the body was made up of various tissues, that in turn were made up of millions of cells, laid rest the humor-theories about chemical imbalances in the body. The age of ] was born. | With the widespread use of the microscope in the 18th century, it was discovered that the 'cancer poison' spread from the primary tumor through the lymph nodes to other sites ("]"). The use of ] to treat cancer had poor results due to problems with hygiene. The renowned Scottish surgeon ] saw only 2 breast tumor patients out of 60 surviving surgery for two years. In the 19th century, ] improved surgical hygiene and as the survival statistics went up, surgical removal of the tumor became the primary treatment for cancer. With the exception of ] who in the late 1800s felt that the rate of cure after surgery had been higher ''before'' asepsis (and who injected bacteria into tumors with mixed results), cancer treatment became dependent on the individual art of the surgeon at removing a tumor. During the same period, the idea that the body was made up of various tissues, that in turn were made up of millions of cells, laid rest the humor-theories about chemical imbalances in the body. The age of ] was born. | ||
| When ] and ] discovered ] at the end of the 19th century, they stumbled upon the first |
When ] and ] discovered ] at the end of the 19th century, they stumbled upon the first medical community observed that the bone marrow of bomb victims in ] and ] was completely destroyed. They concluded that diseased bone marrow could also be with cancer. Advocating for healthy public policy. | ||
| * [http://www.aaTcr.org/home/survivors--advocates.aspx American | |||
| Cancer patient treatment and studies were restricted to individual physicians' practices until ], when medical research centers discovered that there were large international differences in disease ]. This insight drove national public health bodies to make it possible to compile health data across practises and hospitals, a process that many countries do today. The Japanese medical community observed that the bone marrow of bomb victims in ] and ] was completely destroyed. They concluded that diseased bone marrow could also be destroyed with radiation, and this led to the discovery of bone marrow transplants for ]. Since WWII, trends in ] are to improve on a micro-level the existing treatment methods, standardize them, and globalize them as a way to find cures through ] and international partnerships. | |||
| ==Nomenclature and classification== | |||
| The following closely related terms may be used to designate abnormal growths: | |||
| * '']'' and ''neoplasm'' are the scientific designations for cancerous diseases. This group contains a large number of different diseases. Neoplasms can be '']'' or '']''. | |||
| * ''Cancer'' is a widely used word that is usually understood as synonymous with ''malignant neoplasm''. It is occasionally used instead of ], a sub-group of malignant neoplasms. Because of its overwhelming popularity relative to 'neoplasia', it is used frequently instead of 'neoplasia', even by scientists and physicians, especially when discussing neoplastic diseases as a group. | |||
| * '']'' in medical language simply means swelling or lump, either neoplastic, inflammatory or other. In common language, however, it is synonymous with 'neoplasm', either benign or malignant. This is inaccurate since some neoplasms do not usually form tumors, for example ] or ]. | |||
| * '']'' is a disturbance associated with a neoplasm but not related to the invasion of the primary or a secondary (metastatic) tumour. Disturbances can be hormonal, neurological, hematological, biochemical or otherwise clinical. | |||
| Cancers are classified by the type of cell that resembles the tumor and, therefore, the tissue presumed to be the origin of the tumor. The following general categories are usually accepted: | |||
| * ]: malignant tumors derived from ] cells. This group represents the most common cancers, including the common forms of ], ], ] and ] cancer. | |||
| * ] and ]: malignant tumors derived from ] and ] cells | |||
| * ]: malignant tumors derived from ], or ] cells | |||
| * ]: tumors derived from the ] cells lining the ] and the ]. | |||
| * ]: tumors derived from glia, the most common type of ] cell | |||
| * ]: tumors derived from germ cells, normally found in the ] and ] | |||
| * ]: malignant tumors derived from the ] | |||
| Malignant tumors are usually named using the Latin or Greek root of the organ as a prefix and the above category name as the suffix. For instance, a malignant tumor of liver cells is called ''hepatocarcinoma''; a malignant tumor of the fat cells is called ''liposarcoma''. For common cancers, the English organ name is used. For instance, the most common type of ] is called ''ductal carcinoma of the breast'' or ''mammary ductal carcinoma''. Here, the adjective ''ductal'' refers to the appearance of the cancer under the microscope, resembling normal breast ducts. | |||
| Benign tumors are named using '''-oma''' as a suffix with the organ name as the root. For instance, a benign tumor of the smooth muscle of the uterus is called ''leiomyoma'' (the common name of this frequent tumor is ''fibroid''). | |||
| ===Adult cancers=== | |||
| In the USA and other developed countries, cancer is presently responsible for about 25% of all deaths.<ref name="CACancerJClin2005-Jemal"> | |||
| {{cite journal | author=Jemal A, Murray T, Ward E, Samuels A, Tiwari RC, Ghafoor A, Feuer EJ, Thun MJ | title=Cancer statistics, 2005 | journal=CA Cancer J Clin | year=2005 | pages=10-30 | volume=55 | issue=1 | url=http://caonline.amcancersoc.org/cgi/content/full/55/1/10 | id=PMID 15661684}}</ref> On a yearly basis, 0.5% of the population is diagnosed with cancer. | |||
| The statistics below are for adults in the United States, and will vary substantially in other countries: | |||
| {| class="wikitable" | |||
| ! colspan="2" | <big>Male</big> | |||
| | rowspan="7" | | |||
| ! colspan="2" | <big>Female</big> | |||
| |- | |||
| ! width="170px" | most common !! width="170px" | cause of death<ref name="CACancerJClin2005-Jemal" /> | |||
| ! width="170px" | most common !! width="170px" | cause of death<ref name="CACancerJClin2005-Jemal" /> | |||
| |- | |||
| |] (33%) || lung cancer (31%) || ] (32%) || lung cancer (27%) | |||
| |- | |||
| | ] (13%) || prostate cancer (10%) || lung cancer (12%) || breast cancer (15%) | |||
| |- | |||
| | ] (10%) || colorectal cancer (10%) || colorectal cancer (11%) || colorectal cancer (10%) | |||
| |- | |||
| | ] (7%) || ] (5%) || ] (6%) || ] (6%) | |||
| |- | |||
| | cutaneous ] (5%) || ] (4%) || ] (4%) || pancreatic cancer (6%) | |||
| |} | |||
| ===Childhood cancers=== | |||
| Cancer can also occur in young children and adolescents, but it is rare. Some studies have concluded that pediatric cancers, especially leukemia, are on an upward trend.<ref name="Haematologica2005-Dalmasso"> | |||
| {{cite journal | author=Dalmasso P, Pastore G, Zuccolo L, Maule MM, Pearce N, Merletti F, Magnani C | title=Temporal trends in the incidence of childhood leukemia, lymphomas and solid tumors in north-west Italy,. A report of the Childhood Cancer Registry of Piedmont | journal=Haematologica | year=2005 | pages=1197-204 | volume=90 | issue=9 | id=PMID}}</ref><ref name="IntJCancer2005-Agha">{{cite journal | author=Agha M, Dimonte B, Greenberg M, Greenberg C, Barr R, McLaughlin JR | title=Incidence trends and projections for childhood cancer in Ontario | journal=Int J Cancer | year=2005 | pages= | volume= | id=PMID}}</ref> | |||
| The age of peak incidence of cancer in children occurs during the first year of life. ] (usually ]) is the most common infant malignancy (30%), followed by the central nervous system cancers and ]. The remainder consists of ], ]s, ] (arising from muscle), ], ] and ].<ref name="CACancerJClin2005-Jemal" /> | |||
| Female and male infants have essentially the same overall cancer incidence rates, but white infants have substantially higher cancer rates than black infants for most cancer types. Relative survival for infants is very good for neuroblastoma, ] and ], and fairly good (80%) for leukemia, but not for most other types of cancer. | |||
| ==Causes and pathophysiology== | |||
| {{main|Carcinogenesis}} | |||
| ===Origins of cancer=== | |||
| ] or cell proliferation is a physiological process that occurs in almost all tissues and under many circumstances. Normally the balance between proliferation and ] is tightly regulated to ensure the integrity of organs and ]. Mutations in ] that lead to cancer disrupt these orderly processes. | |||
| The uncontrolled and often rapid proliferation of cells can lead to either a ] ] or a ] tumor (cancer). Benign tumors do not spread to other parts of the body or invade other tissues, and they are rarely a threat to life unless they extrinsically compress vital structures. Malignant tumors can invade other organs, spread to distant locations (]) and become life-threatening. | |||
| A few types of cancer in non-humans have been found to be contagious ("]"), such as ], which affects ]s. The closest known analog to this in humans is individuals who have "caught cancer" from tumors hiding inside organ transplants.<ref>{{cite web | title=Study Finds That a Type of Cancer in Dogs Is Contagious | url=http://www.washingtonpost.com/wp-dyn/content/article/2006/08/10/AR2006081001535.html | accessdate=2007-01-19}}</ref> | |||
| ===Molecular biology=== | |||
| ] | |||
| '']'', which means the initiation or generation of cancer, is the process of derangement of the rate of cell division due to damage to ]. Cancer is, ultimately, a disease of ]s. In order for cells to start dividing uncontrollably, genes which regulate cell growth must be damaged. ]s are genes which promote cell growth and ], a process of cell division, and ]s discourage cell growth, or temporarily halt cell division in order to carry out ]. Typically, a series of several ]s to these genes are required before a normal cell transforms into a cancer cell. | |||
| Proto-oncogenes promote cell growth through a variety of ways. Many can produce ]s, a "chemical messenger" between cells which encourage mitosis, the effect of which depends on the ] of the receiving tissue or cells. Some are responsible for the signal transduction system and signal ]s in cells and tissues themselves, thus controlling the sensitivity to such hormones. They often produce ]s, or are involved in ] of DNA in ], which creates the ]s and ]s responsible for producing the products and ] cells use and interact with. | |||
| Mutations in proto-oncogenes can modify their ] and function, increasing the amount or activity of the product protein. When this happens, they become ]s, and thus cells have a higher chance to divide excessively and uncontrollably. The chance of cancer cannot be reduced by removing proto-oncogenes from the ] as they are critical for growth, repair and ] of the body. It is only when they become mutated that the signals for growth become excessive. | |||
| Tumor suppressor genes code for anti-proliferation signals and proteins that suppress mitosis and cell growth. Generally tumor suppressors are ]s that are activated by cellular ] or DNA damage. Often DNA damage will cause the presence of free-floating genetic material as well as other signs, and will trigger enzymes and pathways which lead to the activation of tumor suppressor genes. The functions of such genes is to arrest the progression of cell cycle in order to carry out DNA repair, preventing mutations from being passed on to daughter cells. Canonical tumor suppressors include the ] protein, which is a transcription factor activated by many cellular stressors including ] and ] damage. | |||
| Despite nearly half of all cancers possibly involving alterations in ], its tumor suppressor function is poorly understood. It is clear it has two functions: one a nuclear role as a transcription factor, and the other a cytoplasmic role in cell cycle and division regulation and apoptosis. | |||
| The ] is the preferential use of glycolysis for energy to sustain cancer growth. p53 has been shown to regulate the shift from the respiratory to the glycolytic pathway. Synthesis of Cytochrome c Oxidase 2 (SCO2) has been recognized as the downstream mediator of this effect. SCO2 is critical for regulating the cytochrome c oxidase complex within the mitochondria, and p53 can disrupt the SCO2 gene. P53 regulation of SCO2 and mitochondrial respiration may provide a possible explanation for the Warburg effect.<ref name="Mantoba-Warburg">{{cite journal | author = Matoba S, Kang J, Patino W, Wragg A, Boehm M, Gavrilova O, Hurley P, Bunz F, Hwang P | title = p53 regulates mitochondrial respiration. | journal = Science | volume = 312 | issue = 5780 | pages = 1650-3 | year = 2006 | id = PMID 16728594}}</ref> | |||
| However, a mutation can damage the tumor suppressor gene itself, or the signal pathway which activates it, "switching it off". The invariable consequence of this is that DNA repair is hindered or inhibited: DNA damage accumulates without repair, inevitably leading to cancer. | |||
| In general, mutations in both types of genes are required for cancer to occur. For example, a mutation limited to one oncogene would be suppressed by normal mitosis control and tumor suppressor genes, which was first ] as the ]. A mutation to only one tumor suppressor gene would not cause cancer either, due to the presence of many "]" genes that duplicate its functions. It is only when enough proto-oncogenes have mutated into oncogenes, and enough tumor suppressor genes deactivated or damaged, that the signals for cell growth overwhelm the signals to regulate it, that cell growth quickly spirals out of control. Often, because these genes regulate the processes that prevent most damage to genes themselves, the rate of mutations increase as one gets older, because DNA damage forms a ] loop. Knudson’s two hit model has recently been challenged by several investigators. Inactivation of one allele of some tumor suppressor genes is sufficient to cause tumors. This phenomenon is called haploinsufficiency and has been demonstrated by a number of experimental approaches. Tumors caused by ] usually have a later age of onset when compared with those by a two hit process.<ref name="Fodde-Haploinsufficiency">{{cite journal | author = Fodde R, Smits R | title = Cancer biology. A matter of dosage. | journal = Science | volume = 298 | issue = 5594 | pages = 761-3 | year = 2002 | id = PMID 12399571}}</ref> | |||
| Usually, oncogenes are ], as they contain ]s, while mutated tumor suppressors are ], as they contain ]s. Each cell has two copies of the same gene, one from each parent, and under most cases gain of function mutation in one copy of a particular proto-oncogene is enough to make that gene a true oncogene, while usually loss of function mutation needs to happen in both copies of a tumor suppressor gene to render that gene completely non-functional. However, cases exist in which one loss of function copy of a tumor suppressor gene can render the other copy non-functional. This phenomenon is called the ''dominant negative effect'' and is observed in many p53 mutations. | |||
| Mutation of tumor suppressor genes that are passed on to the next generation of not merely cells, but their ] can cause increased likelihoods for cancers to be inherited. Members of these families have increased incidence and decreased latency of multiple tumors. The mode of inheritance of mutant tumor suppressors is that an affected member inherits a defective copy from one parent, and a normal copy from the other. Because mutations in tumor suppressor genes act in a recessive manner (although there are exceptions), the loss of the normal copy creates the cancer ]. For instance, individuals who are ] for ''p53'' mutations are often victims of ], and those who are heterozygous for '']'' mutations develop ]. Similarly, mutations in the '']'' gene are linked to ], with thousands of polyps in colon while young, while mutations in '']'' and '']'' lead to early onset of ]. | |||
| Cancer pathology is ultimately due to the accumulation of DNA mutations that negatively effect expression of tumour suppressor proteins or positively effect the expression of proteins that drive the cell cycle. Substances that cause these mutations are known as mutagens, and mutagens that cause cancers are known as carcinogens. Particular substances have been linked to specific types of cancer. ] is associated with ]. Prolonged exposure to ], particularly ] from the ], leads to ] and other skin malignancies. Breathing ] fibers is associated with ]. In more general terms, chemicals called ]s and ]s are known to cause mutations. Other types of mutations can be caused by chronic ], as ]s secrete free radicals that damage DNA. ]s, such as the ], are a special type of mutation that involve exchanges between different chromosomes. | |||
| Many ]s are also ]s, but some carcinogens are not mutagens. Examples of carcinogens that are not mutagens include ] and ]. These are thought to promote cancers through their stimulating effect on the rate of cell ]. Faster rates of mitosis increasingly leave less opportunities for repair enzymes to repair damaged DNA during ], increasing the likelihood of a genetic mistake. A mistake made during mitosis can lead to the daughter cells receiving the wrong number of ], which leads to ] and may lead to cancer. | |||
| Furthermore, many cancers originate from a ] ]; this is especially true in animals such as ]s, but also in ]s, as viruses are responsible for 15% of human cancers worldwide. The main viruses associated with human cancers are ], ] virus, ], and ]. Experimental and epidemiological data imply a causative role for viruses and they appear to be the second most important risk factor for cancer development in humans, exceeded only by tobacco usage.<ref name="zur Hausen-viruses">{{cite journal | author = zur Hausen H | title = Viruses in human cancers. | journal = Science | volume = 254 | issue = 5035 | pages = | year = 1991 | id = PMID}}</ref> The mode of virally-induced tumors can be divided into two, ''acutely-transforming'' or ''slowly-transforming''. In acutely transforming viruses, the viral particles carry a gene that encodes for an overactive oncogene called viral-oncogene (v-onc), and the infected cell is transformed as soon as v-onc is expressed. In contrast, in slowly-transforming viruses, the virus genome is inserted, especially as viral genome insertion is an obligatory part of ]es, near a proto-oncogene in the host genome. The viral ] or other transcription regulation elements in turn cause overexpression of that proto-oncogene, which in turn induces uncontrolled cellular proliferation. Because viral genome insertion is not specific to proto-oncogenes and the chance of insertion near that proto-oncogene is low, slowly-transforming viruses have very long tumor latency compared to acutely-transforming viruses, which already carry the viral-oncogene. | |||
| It is impossible to tell the initial cause for any specific cancer. However, with the help of ] techniques, it is possible to characterize the mutations or chromosomal aberrations within a tumor, and rapid progress is being made in the field of predicting ] based on the spectrum of mutations in some cases. For example, some tumors have a defective p53 gene. This mutation is associated with poor prognosis, since those tumor cells are less likely to go into ] or ] when damaged by therapy. ] mutations remove additional barriers, extending the number of times a cell can divide. Other mutations enable the tumor to ] to provide more nutrients, or to ], spreading to other parts of the body. | |||
| <!-- more elaboration here, maybe fork off to another article? --> | |||
| Malignant tumor cells have distinct properties: | |||
| * evading ] | |||
| * unlimited growth potential (immortalitization) due to overabundance of ] | |||
| * self-sufficiency of ]s | |||
| * insensitivity to anti-growth factors | |||
| * increased ] rate | |||
| * altered ability to ] | |||
| * no ability for ] | |||
| * ability to invade neighbouring ]s | |||
| * ability to build ] at distant sites | |||
| * ability to promote blood vessel growth (]) | |||
| A cell that degenerates into a tumor cell does not usually acquire all these properties at once, but its descendant cells are ] to build them. This process is called ]. A first step in the development of a tumor cell is usually a small change in the DNA, often a ], which leads to a genetic instability of the cell. The instability can increase to a point where the cell loses whole ]s, or has multiple copies of several. Also, the ] pattern of the cell changes, activating and deactivating ]s without the usual regulation. Cells that divide at a high rate, such as ]s, show a higher risk of becoming tumor cells than those which divide less, for example ]s. | |||
| ===Morphology=== | |||
| ] | |||
| Cancer tissue has a distinctive appearance under the ]. Among the distinguishing traits are a large number of dividing cells, variation in ] size and shape, variation in cell size and shape, loss of specialized cell features, loss of normal tissue organization, and a poorly defined tumor boundary. ] and other molecular methods may characterise specific markers on tumor cells, which may aid in diagnosis and prognosis. | |||
| Biopsy and microscopical examination can also distinguish between malignancy and ], which refers to tissue growth based on an excessive rate of cell division, leading to a larger than usual number of cells but with a normal orderly arrangement of cells within the tissue. This process is considered reversible. Hyperplasia can be a normal tissue response to an irritating stimulus, for example ]. | |||
| ] is an abnormal type of excessive cell proliferation characterized by loss of normal tissue arrangement and cell structure. Often such cells revert to normal behavior, but occasionally, they gradually become malignant. | |||
| The most severe cases of dysplasia are referred to as "]." In Latin, the term "in situ" means "in place", so carcinoma in situ refers to an uncontrolled growth of cells that remains in the original location and shows no propensity to invade other tissues. Nevertheless, carcinoma in situ may develop into an invasive malignancy and is usually removed surgically, if possible. | |||
| ===Heredity=== | |||
| Most forms of cancer are "sporadic", and have no basis in heredity. There are, however, a number of recognised ]s of cancer with a hereditary component, often a defective tumor suppressor ]. Examples are: | |||
| * certain inherited mutations in the genes '']'' and '']'' are associated with an elevated risk of ] and ] | |||
| * tumors of various endocrine organs in ] (MEN types 1, 2a, 2b) | |||
| * ] (various tumors such as ], breast cancer, ], ]s) due to mutations of ] | |||
| * ] (]s and colonic polyposis) | |||
| * ] an inherited mutation of the ''APC'' gene that leads to early onset of ]. | |||
| * ] in young children is an inherited cancer | |||
| ===Lifestyle factors=== | |||
| ] | |||
| The most consistent finding, over decades of research, is the strong association between ] use and cancers of many sites. Hundreds of epidemiological studies have confirmed this association. Further support comes from the fact that ] death rates in the United States have mirrored ] patterns, with increases in smoking followed by dramatic increases in lung cancer death rates and, more recently, decreases in smoking followed by decreases in lung cancer death rates in men. Lifestyle choices cause cancer: tobacco, diet, exercise, alcohol, tanning choices, and certain sexually transmitted diseases are the major risks. "Most cancers are related to known lifestyle factors."<ref>Update: Is There a Cancer Epidemic in the United States? American Council on Science and Health, 1995.</ref> | |||
| There is also a growing body of research that correlates cancer incidence with the lower levels of ] produced in the body when people spend more time in bright-light conditions{{Fact|date=February 2007}}, as happens typically in the well-lit nighttime environments of the more developed countries. This effect is compounded in people who sleep fewer hours and in people who work at night, two groups that are known{{Fact|date=February 2007}} to have higher cancer rates. | |||
| ==Epidemiology== | |||
| Cancer ] is the study of the incidence of cancer as a way to infer possible trends and causes. The first such cause of cancer was identified by British surgeon ], who discovered in ] that cancer of the ] was a common disease among ]s. The work of other individual physicians led to various insights, but when physicians started working together they could make firmer conclusions. | |||
| A founding paper of this discipline was the work of ], who published a comparative study in ] of 500 breast cancer cases and 500 control patients of the same background and lifestyle for the British Ministry of Health. Her ground-breaking work on cancer epidemiology was carried on by ] and ], who published "] and Other Causes of Death In Relation to ]. A Second Report on the Mortality of British Doctors" followed in ] (otherwise known as the ]). Richard Doll left the ] Medical Research Center (MRC), to start the ] unit for Cancer epidemiology in ]. With the use of ]s, the unit was the first to compile large amounts of cancer data. Modern epidemiological methods are closely linked to current concepts of disease and ] policy. Over the past 50 years, great efforts have been spent on gathering data across medical practise, hospital, provincial, state, and even country boundaries, as a way to study the interdependence of environmental and cultural factors on cancer incidence. | |||
| The biggest problem facing cancer epidemiology today is the changing concept of 'cancer ]'. For example, a ] ] with a very slow growth rate may be found with a ] at 50 years, while the same tumor may have been found as a noteworthy 'lump' at 70 years, depending on the specific growth factors affecting that particular patient's case. As ] tools improve, this has a direct impact on the epidemiological data. | |||
| In some Western countries, such as the USA,<ref name="CACancerJClin2005-Jemal" /> and the UK<ref name="BBC2000-news"> | |||
| (] ]). ''BBC News online''. Retrieved ].</ref> cancer is overtaking ] as the leading cause of death. In many ] countries cancer incidence (insofar as this can be measured) appears much lower, most likely because of the higher death rates due to infectious disease or injury. With the increased control over ] and ] in some Third World countries, incidence of cancer is expected to rise; this is termed the epidemiologic transition in ] terminology. | |||
| Cancer epidemiology closely mirrors risk factor spread in various countries. ] (] cancer) is rare in the West but is the main cancer in ] and neighboring countries, most likely due to the ] presence of ] and ] in that population. Similarly, with ] becoming more common in various Third World countries, ] cancer incidence has increased in a parallel fashion. | |||
| ==Prevention== | |||
| Cancer prevention is defined as active measures to decrease the incidence of cancer. This can be accomplished by avoiding ]s or altering their ], pursuing a lifestyle or diet that modifies cancer-causing factors and/or medical intervention (], treatment of pre-malignant lesions). | |||
| Much of the promise for cancer prevention comes from observational epidemiologic studies that show associations between modifiable life style factors or environmental exposures and specific cancers. Evidence is now emerging from randomized controlled trials designed to test whether interventions suggested by the epidemiologic studies, as well as leads based on laboratory research, actually result in reduced cancer incidence and mortality. | |||
| Examples of modifiable cancer risk include ] consumption (associated with increased risk of oral, esophageal, breast, and other cancers), smoking (although 20% of women with lung cancer have never smoked, versus 10% of men<ref>{{cite web | title= Lung Cancer in American Women: Facts | url=http://www.nationallungcancerpartnership.org/page.cfm?l=factsWomen | accessdate=2007-01-19 }}</ref>), physical inactivity (associated with increased risk of colon, breast, and possibly other cancers), and being ] (associated with colon, breast, endometrial, and possibly other cancers). Based on epidemiologic evidence, it is now thought that avoiding excessive alcohol consumption, being physically active, and maintaining recommended body weight may all contribute to reductions in risk of certain cancers; however, compared with tobacco exposure, the magnitude of effect is modest or small and the strength of evidence is often weaker. Other lifestyle and environmental factors known to affect cancer risk (either beneficially or detrimentally) include certain sexually transmitted diseases, the use of exogenous hormones, exposure to ] and ] radiation, certain occupational and chemical exposures, and infectious agents. | |||
| See ] for more on that topic. | |||
| ===Diet and cancer=== | |||
| The consensus on diet and cancer is that ] increases the risk of developing cancer. Particular dietary practices often explain differences in cancer incidence in different countries (e.g. ] is more common in ], while ] is more common in the United States). Studies have shown that immigrants develop the risk of their new country, suggesting a link between diet and cancer rather than a genetic basis. {{Fact|date=February 2007}} | |||
| Despite frequent reports of particular substances (including foods) having a beneficial or detrimental effect on cancer risk, few of these have an established link to cancer. These reports are often based on studies in cultured cell media or animals. Public health recommendations cannot be made on the basis of these studies until they have been validated in an observational (or occasionally a prospective interventional) trial in humans. | |||
| The case of ] provides an example of the necessity of randomized clinical trials. ] studying both diet and serum levels observed that high levels of ], a precursor to ], were associated with a protective effect, reducing the risk of cancer. This effect was particularly strong in lung cancer. This hypothesis led to a series of large randomized trials conducted in both ] and the ] (CARET study) during the 1980s and 1990s. This study provided about 80,000 smokers or former smokers with daily supplements of beta-carotene or ]s. Contrary to expectation, these tests found no benefit of ] supplementation in reducing lung cancer incidence and mortality. In fact, the risk of lung cancer was slightly, but not significantly, increased by beta-carotene, leading to an early termination of the study.<ref name="CancerTopics-Bcarotene">National Cancer Institute U.S. National Institutes of Health</ref> | |||
| ===Other chemoprevention agents=== | |||
| Daily use of ], a ] (SERM), typically for 5 years, has been demonstrated to reduce the risk of developing ] in high-risk women by about 50%. A recent study reported that the ] ] has similar benefits to ] in preventing breast cancer in high-risk women, with a more favorable side effect profile. | |||
| <ref>{{cite journal |author=Vogel V, Costantino J, Wickerham D, Cronin W, Cecchini R, Atkins J, Bevers T, Fehrenbacher L, Pajon E, Wade J, Robidoux A, Margolese R, James J, Lippman S, Runowicz C, Ganz P, Reis S, McCaskill-Stevens W, Ford L, Jordan V, Wolmark N |title=Effects of tamoxifen vs raloxifene on the risk of developing invasive breast cancer and other disease outcomes: the NSABP Study of Tamoxifen and Raloxifene (STAR) P-2 trial |journal=JAMA |volume=295 |issue=23 |pages=2727-41 |year=2006 |pmid=16754727}}</ref> | |||
| ], a ], has been shown to lower the risk of prostate cancer, though it seems to mostly prevent low-grade tumors. | |||
| <ref>{{cite journal |author=Thompson I, Goodman P, Tangen C, Lucia M, Miller G, Ford L, Lieber M, Cespedes R, Atkins J, Lippman S, Carlin S, Ryan A, Szczepanek C, Crowley J, Coltman C |title=The influence of finasteride on the development of prostate cancer |journal=N Engl J Med |volume=349 |issue=3 |pages=215-24 |year=2003 |pmid=12824459}}</ref> | |||
| The effect of ] such as ] and ] upon the risk of colon polyps have been studied in ] patients | |||
| <ref>{{cite journal |author=Hallak A, Alon-Baron L, Shamir R, Moshkowitz M, Bulvik B, Brazowski E, Halpern Z, Arber N |title=Rofecoxib reduces polyp recurrence in familial polyposis |journal=Dig Dis Sci |volume=48 |issue=10 |pages=1998-2002 |year=2003 |pmid=14627347}}</ref> | |||
| and in the general population. | |||
| <ref>{{cite journal |author=Baron J, Sandler R, Bresalier R, Quan H, Riddell R, Lanas A, Bolognese J, Oxenius B, Horgan K, Loftus S, Morton D |title=A randomized trial of rofecoxib for the chemoprevention of colorectal adenomas |journal=Gastroenterology |volume=131 |issue=6 |pages=1674-82 |year=2006 |pmid=17087947}}</ref><ref>{{cite journal |author=Bertagnolli M, Eagle C, Zauber A, Redston M, Solomon S, Kim K, Tang J, Rosenstein R, Wittes J, Corle D, Hess T, Woloj G, Boisserie F, Anderson W, Viner J, Bagheri D, Burn J, Chung D, Dewar T, Foley T, Hoffman N, Macrae F, Pruitt R, Saltzman J, Salzberg B, Sylwestrowicz T, Gordon G, Hawk E |title=Celecoxib for the prevention of sporadic colorectal adenomas |journal=N Engl J Med |volume=355 |issue=9 |pages=873-84 |year=2006 |pmid=16943400}}</ref> | |||
| In both groups, there were significant reductions in ] ], but this came at the price of increased cardiovascular toxicity. | |||
| ===Genetic testing=== | |||
| ] for high-risk individuals is already available for certain cancer-related genetic mutations. Carriers of genetic mutations that increase risk for cancer incidence can undergo enhanced surveillance, chemoprevention, or risk-reducing surgery. | |||
| {| class="wikitable" | |||
| |- | |||
| ! Gene | |||
| ! Cancer types | |||
| ! Availability | |||
| |- | |||
| | ], ] | |||
| | Breast, ovarian, pancreatic | |||
| | Commercially available for clinical specimens | |||
| |- | |||
| | ], ], ], ], ] | |||
| | Colon, uterine, small bowel, stomach, urinary tract | |||
| | Commercially available for clinical specimens | |||
| |} | |||
| ==Diagnosing cancer== | |||
| Most cancers are initially recognized either because signs or symptoms appear or through screening. Neither of these lead to a definitive diagnosis, which usually requires the opinion of a ]. | |||
| ===Signs and symptoms=== | |||
| Roughly, cancer symptoms can be divided into three groups: | |||
| * ''Local symptoms'': unusual lumps or swelling ('']''), ] (bleeding), ] and/or ]ation. Compression of surrounding tissues may cause symptoms such as ]. | |||
| * ''Symptoms of ] (spreading)'': enlarged ]s, ] and ], ] (enlarged ]), bone pain, ] of affected bones and ] symptoms. Although advanced cancer may cause ], it is often not the first symptom. | |||
| * ''Systemic symptoms'': ], ] and ] (]), excessive ] (]), ] and specific ], i.e. specific conditions that are due to an active cancer, such as ] or hormonal changes. | |||
| Every single item in the above list can be caused by a variety of conditions (a list of which is referred to as the ]). Cancer may be a common or uncommon cause of each item. | |||
| ===Biopsy=== | |||
| A cancer may be suspected for a variety of reasons, but the definitive diagnosis of most malignancies must be confirmed by ] examination of the cancerous cells by a ]. Tissue can be obtained from a ] or ]. Many biopsies (such as those of the skin, breast or liver) can be done in a doctor's office. Biopsies of other organs are performed under ] and require ] in an ]. | |||
| The tissue ] indicates the type of cell that is proliferating, its ] and other features of the tumor. Together, this information is useful to evaluate the ] of this patient and choose the best treatment. ] and ] may provide information about future behavior of the cancer (prognosis) and best treatment. | |||
| ===Screening=== | |||
| Cancer ] is an attempt to detect unsuspected cancers in the population. Screening tests suitable for large numbers of healthy people must be relatively affordable, safe, noninvasive procedures with acceptably low rates of ] results. If signs of cancer are detected, more definitive and invasive follow up tests are performed to confirm the diagnosis. | |||
| Screening for cancer can lead to earlier diagnosis. Early diagnosis may lead to extended life. A number of different screening tests have been developed. Breast cancer screening can be done by ]. Screening by regular ]s detects tumors even earlier than self-examination, and many countries use it to systematically screen all middle-aged women. Colorectal cancer can be detected through ]ing and ], which reduces both colon cancer incidence and mortality, presumably through the detection and removal of pre-malignant polyps. Similarly, cervical cytology testing (using the ]) leads to the identification and excision of precancerous lesions. Over time, such testing has been followed by a dramatic reduction of ] incidence and mortality. ] is recommended for men beginning at the age of 15 years to detect ]. Prostate cancer can be screened for by a ] along with ] (PSA) blood testing. | |||
| Screening for cancer is controversial in cases when it is not yet known if the test actually saves lives. The controversy arises when it is not clear if the benefits of screening outweigh the risks of follow-up diagnostic tests and cancer treatments. For example: when screening for ], the ] test may detect small cancers that would never become life threatening, but once detected will lead to treatment. This situation, called ], puts men at risk for complications from unnecessary treatment such as surgery or radiation. Follow up procedures used to diagnose prostate cancer (]) may cause side effects, including bleeding and infection. Prostate cancer treatment may cause ] (inability to control urine flow) and ] (erections inadequate for intercourse). Similarly, for ], there have recently been criticisms that breast screening programs in some countries cause more problems than they solve. This is because screening of women in the general population will result in a large number of women with false positive results which require extensive follow-up investigations to exclude cancer, leading to having a high number-to-treat (or number-to-screen) to prevent or catch a single case of breast cancer early. | |||
| Cervical cancer screening via the ] has the best cost-benefit profile of all the forms of cancer screening from a public health perspective as, being largely caused by a virus, it has clear risk factors (sexual contact), and the natural progression of cervical cancer is that it normally spreads slowly over a number of years therefore giving more time for the screening program to catch it early. Moreover, the test itself is easy to perform and relatively cheap. | |||
| For these reasons, it is important that the benefits and risks of diagnostic procedures and treatment be taken into account when considering whether to undertake cancer screening. | |||
| Use of ] to search for cancer in people without clear symptoms is similarly marred with problems. There is a significant risk of detection of what has been recently called an '']'' - a benign lesion that may be interpreted as a malignancy and be subjected to potentially dangerous investigations. | |||
| ] has shown promise, but is still in the early stages of research. | |||
| ==Treatment of cancer== | |||
| Cancer can be treated by ], ], ], ], ] or other methods. The choice of therapy depends upon the location and grade of the tumor and the ] of the disease, as well as the general state of the patient (]). A number of ]s are also under development. | |||
| Complete removal of the cancer without damage to the rest of the body is the goal of treatment. Sometimes this can be accomplished by surgery, but the propensity of cancers to invade adjacent tissue or to spread to distant sites by microscopic metastasis often limits its effectiveness. The effectiveness of chemotherapy is often limited by toxicity to other tissues in the body. Radiation can also cause damage to normal tissue. | |||
| Because "cancer" refers to a class of diseases, it is unlikely that there will ever be a single "]" any more than there will be a single treatment for all ]s. | |||
| ===Surgery=== | |||
| In theory, cancers can be cured if entirely removed by ], but this is not always possible. When the cancer has ] to other sites in the body prior to surgery, complete surgical excision is usually impossible. | |||
| Examples of surgical procedures for cancer include ] for breast cancer and ] for prostate cancer. The goal of the surgery can be either the removal of only the tumor, or the entire organ. A single cancer cell is invisible to the naked eye but can regrow into a new tumor, a process called ]. For this reason, the ] will examine the surgical specimen to determine if a margin of healthy tissue is present, thus decreasing the chance that microscopic cancer cells are left in the patient. | |||
| In addition to removal of the primary tumor, surgery is often necessary for ], e.g. determining the extent of the disease and whether it has ] to regional ]s. Staging is a major determinant of ] and of the need for ]. | |||
| Occasionally, surgery is necessary to control symptoms, such as ] or ]. This is referred to as ]. | |||
| ===Chemotherapy=== | |||
| {{main|Chemotherapy}} | |||
| {{see also|History of cancer chemotherapy}} | |||
| ] is the treatment of cancer with ] ("anticancer drugs") that can destroy cancer cells. It interferes with cell division in various possible ways, e.g. with the duplication of ] or the separation of newly formed ]s. Most forms of chemotherapy target all rapidly dividing cells and are not specific for cancer cells. Hence, chemotherapy has the potential to harm healthy tissue, especially those tissues that have a high replacement rate (e.g. intestinal lining). These cells usually repair themselves after chemotherapy. | |||
| Because some drugs work better together than alone, two or more drugs are often given at the same time. This is called "combination chemotherapy"; most chemotherapy regimens are given in a combination. | |||
| The treatment of some ]s and ]s requires the use of high-dose chemotherapy, and ] (TBI). This treatment ablates the bone marrow, and hence the body's ability to recover and repopulate the blood. For this reason, bone marrow, or peripheral blood stem cell harvesting is carried out before the ablative part of the therapy, to enable "rescue" after the treatment has been given. This is known as autologous transplantation. Alternatively, bone marrow may be transplanted from a matched unrelated donor (MUD). | |||
| ===Monoclonal antibody therapy=== | |||
| {{main|Monoclonal antibody therapy}} | |||
| Immunotherapy is the use of ] mechanisms against tumors. These are used in various forms of cancer, such as ] (]/Herceptin®) and ] (]/Mylotarg®). The agents are ] directed against proteins that are characteristic to the cells of the cancer in question, or ]s that modulate the immune system's response. | |||
| ===Immunotherapy=== | |||
| {{main|Cancer immunotherapy}} | |||
| Other, more contemporary methods for generating non-specific immune response against tumours include intravesical ] immunotherapy for superficial bladder cancer, and use of ] and ]. ]s to generate non-specific ]s are the subject of intensive research for a number of tumours, notably ] and ]. | |||
| ===Radiation therapy=== | |||
| {{main|Radiation therapy}} | |||
| ] (also called radiotherapy, X-ray therapy, or irradiation) is the use of ionizing radiation to kill cancer cells and shrink tumors. Radiation therapy can be administered externally via ] (EBRT) or internally via ]. The effects of radiation therapy are localised and confined to the region being treated. Radiation therapy injures or destroys cells in the area being treated (the "target tissue") by damaging their genetic material, making it impossible for these cells to continue to grow and divide. Although radiation damages both cancer cells and normal cells, most normal cells can recover from the effects of radiation and function properly. The goal of radiation therapy is to damage as many cancer cells as possible, while limiting harm to nearby healthy tissue. Hence, it is given in many fractions, allowing healthy tissue to recover between fractions. | |||
| Radiation therapy may be used to treat almost every type of solid tumor, including cancers of the brain, breast, cervix, larynx, lung, pancreas, prostate, skin, stomach, uterus, or soft tissue sarcomas. Radiation is also used to treat leukemia and lymphoma. Radiation dose to each site depends on a number of factors, including the radiosensitivity of each cancer type and whether there are tissues and organs nearby that may be damaged by radiation. Thus, as with every form of treatment, radiation therapy is not without its side effects. | |||
| ===Hormonal suppression=== | |||
| The growth of some cancers can be inhibited by providing or blocking certain hormones. Common examples of hormone-sensitive tumors include certain types of breast and prostate cancers. Removing or blocking ] or ] is often an important additional treatment. | |||
| ===Symptom control=== | |||
| Although the control of the symptoms of cancer is not typically thought of as a treatment directed at the cancer, it is an important determinant of the ] of cancer patients, and plays an important role in the decision whether the patient is able to undergo other treatments. Although all practicing doctors have the therapeutic skills to control pain, nausea, vomiting, diarrhea, hemorrhage and other common problems in cancer patients, the multidisciplinary specialty of ] has arisen specifically in response to the symptom control needs of this group of patients. | |||
| ], such as ] and ], and ]s, drugs to suppress nausea and vomiting, are very commonly used in patients with cancer-related symptoms. | |||
| ] due to cancer is almost always associated with continuing tissue damage due to the disease process or the treatment (i.e. surgery, radiation, chemotherapy). Although there is always a role for environmental factors and affective disturbances in the genesis of pain behaviors, these are not usually the predominant etiologic factors in patients with cancer pain. Furthermore, many patients with severe pain associated with cancer are nearing the end of their lives and ] therapies are required. Issues such as social stigma of using ], work and functional status, and health care consumption are not likely to be important in the overall case management. Hence, the typical strategy for cancer pain management is to get the patient as comfortable as possible using opioids and other medications, surgery, and physical measures. | |||
| ===Treatment trials=== | |||
| ]s, also called research studies, test new treatments in people with cancer. The goal of this research is to find better ways to treat cancer and help cancer patients. Clinical trials test many types of treatment such as new drugs, new approaches to surgery or radiation therapy, new combinations of treatments, or new methods such as ]. | |||
| A clinical trial is one of the final stages of a long and careful cancer research process. The search for new treatments begins in the laboratory, where scientists first develop and test new ideas. If an approach seems promising, the next step may be testing a treatment in animals to see how it affects cancer in a living being and whether it has harmful effects. Of course, treatments that work well in the lab or in animals do not always work well in people. Studies are done with cancer patients to find out whether promising treatments are safe and effective. | |||
| Patients who take part may be helped personally by the treatment(s) they receive. They get up-to-date care from cancer experts, and they receive either a new treatment being tested or the best available standard treatment for their cancer. Of course, there is no guarantee that a new treatment being tested or a standard treatment will produce good results. New treatments also may have unknown risks, but if a new treatment proves effective or more effective than standard treatment, study patients who receive it may be among the first to benefit. | |||
| ===Cancer vaccines=== | |||
| Considerable research effort is now devoted to the development of ]s (to prevent infection by oncogenic infectious agents, as well as to mount an immune response against cancer-specific ]s) and to potential venues for ] for individuals with genetic mutations or polymorphisms that put them at high risk of cancer. | |||
| As of ], researchers found that an experimental vaccine for ] types 16 and 18 was 100% successful at preventing infection with these types of HPV and, thus, are able to prevent the majority of cervical cancer cases.<ref name="Lancet2004-Harper"> | |||
| {{cite journal | author=Harper DM, Franco EL, Wheeler C, Ferris DG, Jenkins D, Schuind A, Zahaf T, Innis B, Naud P, De Carvalho NS, Roteli-Martins CM, Teixeira J, Blatter MM, Korn AP, Quint W, Dubin G | title=Efficacy of a bivalent L1 virus-like particle vaccine in prevention of infection with human papillomavirus types 16 and 18 in young women: a randomised controlled trial | journal=Lancet | year=2004 | pages=1757-65 | volume=364 | issue=9447 | id=PMID}}</ref> | |||
| ===Complementary and alternative medicine=== | |||
| ] (CAM) treatments are the diverse group of medical and health care systems, practices, and products that are not part of conventional medicine. ], the study of human cancer, has a long history of incorporating unconventional or botanical treatments into mainstream cancer therapy. Some examples of this phenomenon include the ] ], which is derived from the bark of the ], and ], all-trans retinoic acid, a derivative of ] that induces cures in an aggressive ] known as ]. Many "complementary" and "alternative" medicines for ] have not been studied using the ], such as in well-designed ], or they have only been studied in preclinical (animal or ]) laboratory studies. Many times, "complementary" and "alternative" medicines are supported by marketing materials and "testimonials" from users of the substances. | |||
| "Complementary medicine" refers to substances used along with conventional medicine, while "alternative medicine" refers to compounds used instead of conventional medicine. A study of CAM use in patients with cancer in the July 2000 issue of the Journal of Clinical Oncology found that 69 percent of 453 cancer patients had used at least one CAM therapy as part of their cancer treatment.<ref>{{cite web | title= National Center for Complementary and Alternative Medicine’s Cancer FAQ | url=http://nccam.nih.gov/health/camcancer/| accessdate=2007-03-01}}</ref> | |||
| Some ''complementary'' measures include ], such as an ] trial currently underway testing mistletoe extract combined with ] for the treatment of solid tumors, ] for managing chemotherapy-associated nausea and vomiting and in controlling pain associated with surgery, ], psychological approaches such as "]" or ] to aid in pain relief or improve mood.<ref>{{cite web | title= National Center for Complementary and Alternative Medicine’s Cancer FAQ | url=http://nccam.nih.gov/health/camcancer/| accessdate=2007-03-01}}</ref> | |||
| A wide range of ''alternative'' treatments have been offered for cancer over the last century. The appeal of alternative cures arises from the daunting risks, costs, or potential side effects of many conventional treatments, or in the limited prospect for cure. No alternative therapies have been shown in randomized controlled trials to effectively cure cancer by themselves, although the Journal of Urology published a study in 2005 <ref name="Ornish">{{cite journal | author = Ornish D et al. | title = Intensive lifestyle changes may affect the progression of prostrate cancer | journal = The Journal of Urology | volume = 174 | issue = 3 | pages = 1065-9; discussion 1069-70 | year = 2005 | id = PMID 16094059}}</ref> demonstrating that a consuming plant based diet and making other lifestyle changes was able to reduce cancer markers in a group of men with prostate cancer using no conventional treatments. Other (unproven) anti-cancer diets include the grape diet and the cabbage diet. | |||
| ==Coping with cancer== | |||
| Many local organizations offer a variety of practical and support services to people with cancer. Support can take the form of ], ], advice, financial assistance, transportation to and from treatment, films or information about cancer. Neighborhood organizations, local health care providers, or area hospitals may have resources or services available. | |||
| While some people are reluctant to seek counseling, studies show that having someone to talk to reduces stress and helps people both mentally and physically. Counseling can also provide emotional support to cancer patients and help them better understand their illness. Different types of counseling include individual, group, family, self-help (sometimes called peer counseling), bereavement, patient-to-patient, and sexuality. | |||
| Many governmental and charitable organizations have been established to help patients cope with cancer. These organizations often are involved in cancer prevention, cancer treatment, and cancer research. Examples include: ], ], ], ], ], the ], ], ], ], ], ] and the ] (US). | |||
| ==Social impact== | |||
| Cancer has a reputation for being a deadly disease. While this certainly applies to certain particular types, the truths behind the historical connotations of cancer are increasingly being overturned by advances in medical care. Some types of cancer have a prognosis that is substantially better than nonmalignant diseases such as ] and ]. | |||
| Progressive and disseminated malignant disease has a substantial impact on a cancer patient's quality of life, and many cancer treatments (such as ]) may have severe side-effects. In the advanced stages of cancer, many patients need extensive care, affecting family members and friends. ] solutions may include permanent or "respite" ] nursing. | |||
| ==Cancer research== | |||
| {{main|Cancer research}} | |||
| Cancer research is the intense scientific effort to understand disease processes and discover possible therapies. Although understanding of cancer has greatly increased since the last decades of the 20th century, few radically new therapies have been discovered. | |||
| ] which first became available in the late 1990s has had a significant impact in the treatment of some types of cancer, and is currently a very active research area. This constitutes the use of agents specific for the deregulated proteins of cancer cells. Small molecules (such as the tyrosine kinase inhibitors ] and ]) and ] have proven to be a major step in oncological treatment. | |||
| ] can also involve small peptidic structures as ´homing device´ which can bind to cell surface receptors or affected ] surrounding the tumor. Radionuclides which are attached to this peptides (e.g. RGDs) eventually kill the cancer cell if the nuclide decays in the vicinity of the cell (vide supra ]). Especially oligo- or multimeris of these binding motifs are of great interest, since this can lead to enhanced tumor specificity and avidity. | |||
| ==See also== | |||
| {{wiktionary}} | |||
| {{Commons|Cancer (illness)}} | |||
| * ] | |||
| * ] | |||
| * ] | |||
| * ] | |||
| * ] | |||
| * ] | |||
| * ] (EORTC) | |||
| *] | |||
| ==References== | |||
| <!--See http://en.wikipedia.org/Wikipedia:Footnotes for an explanation of how to generate footnotes using the <ref(erences/)> tags--> | |||
| <div class="references-small"> | |||
| <references /> | |||
| ===General references=== | |||
| * ''The Basic Science of Oncology.'' Tannock IF, Hill RP ''et al'' (eds) 4th ed.2005 McGraw-Hill. | |||
| * ''Principles of Cancer Biology.'' Kleinsmith, LJ (2006). Pearson Benjamin Cummings. | |||
| * {{cite web | title=A Special Message to Cancer Patients Seeking "Alternative" Treatments | url=http://www.quackwatch.org/00AboutQuackwatch/altseek.html | accessdate=2005-12-16 }} | |||
| * {{cite journal | author = Parkin D, Bray F, Ferlay J, Pisani P | title = Global cancer statistics, 2002. | journal = CA Cancer J Clin | volume = 55 | issue = 2 | pages = 74-108 | year = | id = PMID}}'''' | |||
| </div> | |||
| ==External links== | |||
| ===Professional and research=== | |||
| * | |||
| * A huge database of various cancers. | |||
| * What to look for in clinical trials and how to find open trials. | |||
| * | |||
| * – Trusted tools for helping patients make informed decisions | |||
| * A non-profit organization supporting advances in the knowledge of causes, diagnosis, treatment and prevention of cancer. | |||
| * A review of worldwide strategies for the prevention and treatment of cancer. | |||
| * | |||
| * US Government agency responsible for conducting and supporting research, training, health information dissemination, and other programs with respect to the cause, diagnosis, prevention, and treatment of cancer, rehabilitation from cancer, and the continuing care of cancer patients and the families of cancer patients. | |||
| * - Free guidelines for professionals and many pages of quality information for patients with all types of cancers | |||
| * One of the world’s foremost independent cancer research organisations, based in the United Kingdom. | |||
| * European Organization for Research and Treatment of Cancer. A European non-profit organization that sets up and executes clinical trials. | |||
| * Society of medical professionals committed to investigating, developing and utilizing biologicals and biological therapy for the treatment of malignant disease. | |||
| * Longest-standing Canadian research organization devoted to advancing cancer control. | |||
| * - 2005 United States Cancer Statistics | |||
| * | |||
| - This publication reports cancer incidence and mortality in Canada, analyzed by gender, age and province/territory. | |||
| * Textbook | |||
| * {{cite web | author =New Scientist | authorlink =New Scientist | year =2006 | url =http://www.newscientist.com/channel/health/cancer | title =Everything you wanted to know about cancer | publisher =New Scientist | accessyear =2006 }} | |||
| * (including cancer) by a Joint ]/] Expert consultation (2003). by ]. | |||
| * - information resource with the latest cancerous diseases news by professionals of Oncology, Haematology, Radiation Oncology and Palliative Care. | |||
| ===Support and advocacy=== | |||
| * Listing of Clinical Practice Guidelines in Oncology - Standards of Care written by leading cancer centers in the U.S.A. | |||
| * Patient advocate group | |||
| * A huge database of various cancers. | |||
| * Northern Ireland Cancer Charity providing screening and support | |||
| * Information on all types of cancer, ways to reduce your risk. Support for people living with cancer. Advocating for healthy public policy. | |||
| * | |||
| * from ] - provides links to news, general sites, diagnosis, treatment and alternative therapies, clinical trials, research, related issues, organizations, other MedlinePlus and , and more. Also, links to pre-formulated searches of the ]/PubMed database for recent research articles. | |||
| * - In-depth, up-to-date information for people with a professional or general interest in cancer and health. | |||
| * - Australia's national non-government cancer control organisation, involved in research, information, prevention, patient treatment and support. | |||
| * - Offers information on childhood cancer, treatment options, and support. . | |||
| * ACOR is a unique collection of online communities designed to provide timely and accurate information in a supportive environment. ACOR offers access to mailing lists that provide support, information, and community to everyone affected by cancer and related disorders. | |||
| * Multimedia guide to cancer biology from Cold Spring Harbor Laboratory | |||
| {{Tumors}} | |||
| ] | ] | ||
| ] | ] | ||
| ] | ] | ||
| ] | ] | ||
| {{Link FA|hu}} | {{Link FA|hu}} | ||
| {{Link FA|pl}} | {{Link FA|pl}}FAT PEOPLE SPREAD CANCER | ||
| {{Link FA|vi}} | {{Link FA|vi}} | ||
Revision as of 21:40, 3 April 2007
There are many types of cancer. Severity of symptoms depends on the site and character of the malignancy and whether there is metastasis. A definitive diagnosis usually requires the [[jhgbdce b7vb vcgj and some cured, depending on the specific type, location, and stage. Once diagnosed, cancer is usually treated with a combination ofsurgery, chemotherapy and radiotherapy. As research develops, treatments are becoming more specific for the type of cancer pathology. Drugs that target specific cancers already exist for several types of cancer. If untreated, cancers may eventually cause illness and , chemicals or physical agents that cause cancer, which are called carcinogens, or by certain viruses that can insert their DNA into the human genome. Mutations occur sphuyr* If a player kicks an opponent
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Many forms of cancer are associated with exposure to environmental factors such as tobacco smoke, radiation, alcohol, and certain viruses. Some risk factors can be avoided or reduced.
History
Today, the Greek term carcinoma is the medical term for a malignant tumor derived from epithelial cells. It is Celsus who translated carcinos into the Latin cancer, also meaning crab. Galen used "oncos" to describe all tumours, the root for the modern word oncology.
Hippocrates described several kinds of cancers. He called benign tumours oncos, Greek for swelling, and malignant tumours carcinos, Greek for crab or crayfish. This name probably comes from the appearance of the cut surface of a solid malignant tumour, with a roundish hard center surrounded by pointy projections, vaguely resembling the shape of a crab (see photo). He later added the suffix -oma, Greek for swelling, giving the name carcinoma. Since it was against Greek tradition to open the body, Hippocrates only described and made drawings of outwardly visible tumors on the skin, nose, and breasts. Treatment was based on the humor theory of four bodily fluids (black and yellow bile, blood, and phlegm). According to the patient's humor, treatment consisted of diet, blood-letting, and/or laxatives. Through the centuries it was discovered that cancer could occur anywhere in the body, but humor-theory based treatment remained popular until the 19th century with the discovery of cells.
Though treatment remained the same, in the 16th and 17th centuries it became more acceptable for doctors to dissect bodies to discover the cause of death. The German professor Wilhelm Fabry believed that breast cancer was caused by a milk clot in a mammary duct. The Dutch professor Francois de la Boe Sylvius, a follower of Descartes, believed that all disease was the outcome of chemical processes, and that acidic lymph fluid was the cause of cancer. His contemporary Nicolaes Tulp believed that cancer was a poison that slowly spreads, and concluded that it was contagious.
With the widespread use of the microscope in the 18th century, it was discovered that the 'cancer poison' spread from the primary tumor through the lymph nodes to other sites ("metastasis"). The use of surgery to treat cancer had poor results due to problems with hygiene. The renowned Scottish surgeon Alexander Monro saw only 2 breast tumor patients out of 60 surviving surgery for two years. In the 19th century, asepsis improved surgical hygiene and as the survival statistics went up, surgical removal of the tumor became the primary treatment for cancer. With the exception of William Coley who in the late 1800s felt that the rate of cure after surgery had been higher before asepsis (and who injected bacteria into tumors with mixed results), cancer treatment became dependent on the individual art of the surgeon at removing a tumor. During the same period, the idea that the body was made up of various tissues, that in turn were made up of millions of cells, laid rest the humor-theories about chemical imbalances in the body. The age of cellular pathology was born.
When Marie Curie and Pierre Curie discovered radiation at the end of the 19th century, they stumbled upon the first medical community observed that the bone marrow of bomb victims in Hiroshima and Nagasaki was completely destroyed. They concluded that diseased bone marrow could also be with cancer. Advocating for healthy public policy.
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- Ralph W. Moss, Ph.D Galen on Cancer - How Ancient Physicians Viewed Malignant Disease 1989 Speech
- Marilyn Yalom "A history of the breast" 1997 Publisher: New York : Alfred A. Knopf ISBN 0-679-43459-3