8/14/2019 Cancer15

1/2

Cancer (medical term: malignantneoplasm) is a class ofdiseases in which a group ofcells display the traits ofuncontrolled growth (growth and division beyond the normallimits), invasion (intrusion on and destruction of adjacent tissues), and sometimesmetastasis (spread to other locations in the body via lymph or blood). These threemalignant properties of cancers differentiate them from benign tumors, which are self-limited, do not invade or metastasize. Most cancers form a tumor but some, likeleukemia, do not.

Cancer may affect people at all ages, even fetuses, but risk for the more commonvarieties tends to increase with age.[1] Cancer causes about 13% of all deaths.[2]

According to the American Cancer Society, 7.6 million people died from cancer in theworld during 2007.[3] Apart from humans, forms of cancer may affect other animalsand plants.

Nearly all cancers are caused by abnormalities in the genetic material of thetransformed cells. These abnormalities may be due to the effects ofcarcinogens, suchas tobacco smoke, radiation, chemicals, or infectious agents. Other cancer-promotinggenetic abnormalities may be randomly acquired through errors in DNA replication, orare inherited, and thus present in all cells from birth. Complex interactions betweencarcinogens and the host genome may explain why only some develop cancer afterexposure to a known carcinogen. New aspects of the genetics of cancer pathogenesis,such as DNA methylation, and microRNAs are increasingly being recognized asimportant.

Genetic abnormalities found in cancer typically affect two general classes of genes.Cancer-promoting oncogenes are often activated in cancer cells, giving those cellsnew properties, such as hyperactive growth and division, protection againstprogrammed cell death, loss of respect for normal tissue boundaries, and the ability tobecome established in diverse tissue environments. Tumor suppressor genes are ofteninactivated in cancer cells, resulting in the loss of normal functions in those cells, such

as accurate DNA replication, control over the cell cycle, orientation and adhesionwithin tissues, and interaction with protective cells of the immune system.

Cancer is usually classified according to the tissue from which the cancerous cellsoriginate, the primary tumor, as well as the normal cell type they most resemble.These are location and histology, respectively. A definitive diagnosis usually requiresthe histologic examination of a tissue biopsy specimen by a pathologist, although theinitial indication of malignancy can be symptoms or radiographic imagingabnormalities. Most cancers can be treated and some cured, depending on thespecific type, location, and stage. Once diagnosed, cancer is usually treated with acombination of surgery, chemotherapy and radiotherapy. As research develops,

treatments are becoming more specific for different varieties of cancer. There hasbeen significant progress in the development of targeted therapy drugs that actspecifically on detectable molecular abnormalities in certain tumors, and whichminimize damage to normal cells. The prognosis of cancer patients is most influencedby the type of cancer, as well as the stage, or extent of the disease. In addition,histologicgrading and the presence of specific molecular markers can also be usefulin establishing prognosis, as well as in determining individual treatments.

http://en.wikipedia.org/wiki/Malignanthttp://en.wikipedia.org/wiki/Neoplasmhttp://en.wikipedia.org/wiki/Diseasehttp://en.wikipedia.org/wiki/Cell_(biology)http://en.wikipedia.org/wiki/Cell_divisionhttp://en.wikipedia.org/wiki/Metastasishttp://en.wikipedia.org/wiki/Malignanthttp://en.wikipedia.org/wiki/Benign_tumorhttp://en.wikipedia.org/wiki/Tumorhttp://en.wikipedia.org/wiki/Leukemiahttp://en.wikipedia.org/wiki/Fetushttp://en.wikipedia.org/wiki/Causes_of_deathhttp://en.wikipedia.org/wiki/American_Cancer_Societyhttp://en.wikipedia.org/wiki/Genomehttp://en.wikipedia.org/wiki/Malignant_transformationhttp://en.wikipedia.org/wiki/Carcinogenshttp://en.wikipedia.org/wiki/Tobacco_smokehttp://en.wikipedia.org/wiki/Electromagnetic_radiationhttp://en.wikipedia.org/wiki/Chemicalshttp://en.wikipedia.org/wiki/Pathogenhttp://en.wikipedia.org/wiki/DNA_replicationhttp://en.wikipedia.org/wiki/Genetic_disorderhttp://en.wikipedia.org/wiki/Genomehttp://en.wikipedia.org/wiki/DNA_methylationhttp://en.wikipedia.org/wiki/MicroRNAshttp://en.wikipedia.org/wiki/Oncogenehttp://en.wikipedia.org/wiki/Programmed_cell_deathhttp://en.wikipedia.org/wiki/Tumor_suppressor_genehttp://en.wikipedia.org/wiki/Cell_cyclehttp://en.wikipedia.org/wiki/Immune_systemhttp://en.wikipedia.org/wiki/Histologyhttp://en.wikipedia.org/wiki/Biopsyhttp://en.wikipedia.org/wiki/Anatomical_pathologyhttp://en.wikipedia.org/wiki/Radiographichttp://en.wikipedia.org/wiki/Cancer_staginghttp://en.wikipedia.org/wiki/Surgeryhttp://en.wikipedia.org/wiki/Chemotherapyhttp://en.wikipedia.org/wiki/Radiation_therapyhttp://en.wikipedia.org/wiki/Targeted_therapyhttp://en.wikipedia.org/wiki/Cancer_staginghttp://en.wikipedia.org/wiki/Histologyhttp://en.wikipedia.org/wiki/Grading_(tumors)http://en.wikipedia.org/wiki/Malignanthttp://en.wikipedia.org/wiki/Malignanthttp://en.wikipedia.org/wiki/Neoplasmhttp://en.wikipedia.org/wiki/Neoplasmhttp://en.wikipedia.org/wiki/Neoplasmhttp://en.wikipedia.org/wiki/Diseasehttp://en.wikipedia.org/wiki/Diseasehttp://en.wikipedia.org/wiki/Diseasehttp://en.wikipedia.org/wiki/Cell_(biology)http://en.wikipedia.org/wiki/Cell_(biology)http://en.wikipedia.org/wiki/Cell_(biology)http://en.wikipedia.org/wiki/Cell_divisionhttp://en.wikipedia.org/wiki/Cell_divisionhttp://en.wikipedia.org/wiki/Cell_divisionhttp://en.wikipedia.org/wiki/Metastasishttp://en.wikipedia.org/wiki/Metastasishttp://en.wikipedia.org/wiki/Metastasishttp://en.wikipedia.org/wiki/Malignanthttp://en.wikipedia.org/wiki/Malignanthttp://en.wikipedia.org/wiki/Malignanthttp://en.wikipedia.org/wiki/Benign_tumorhttp://en.wikipedia.org/wiki/Benign_tumorhttp://en.wikipedia.org/wiki/Benign_tumorhttp://en.wikipedia.org/wiki/Tumorhttp://en.wikipedia.org/wiki/Tumorhttp://en.wikipedia.org/wiki/Tumorhttp://en.wikipedia.org/wiki/Leukemiahttp://en.wikipedia.org/wiki/Leukemiahttp://en.wikipedia.org/wiki/Leukemiahttp://en.wikipedia.org/wiki/Fetushttp://en.wikipedia.org/wiki/Fetushttp://en.wikipedia.org/wiki/Fetushttp://en.wikipedia.org/wiki/Causes_of_deathhttp://en.wikipedia.org/wiki/Causes_of_deathhttp://en.wikipedia.org/wiki/Causes_of_deathhttp://en.wikipedia.org/wiki/American_Cancer_Societyhttp://en.wikipedia.org/wiki/American_Cancer_Societyhttp://en.wikipedia.org/wiki/American_Cancer_Societyhttp://en.wikipedia.org/wiki/Genomehttp://en.wikipedia.org/wiki/Genomehttp://en.wikipedia.org/wiki/Genomehttp://en.wikipedia.org/wiki/Malignant_transformationhttp://en.wikipedia.org/wiki/Malignant_transformationhttp://en.wikipedia.org/wiki/Malignant_transformationhttp://en.wikipedia.org/wiki/Carcinogenshttp://en.wikipedia.org/wiki/Carcinogenshttp://en.wikipedia.org/wiki/Carcinogenshttp://en.wikipedia.org/wiki/Tobacco_smokehttp://en.wikipedia.org/wiki/Tobacco_smokehttp://en.wikipedia.org/wiki/Tobacco_smokehttp://en.wikipedia.org/wiki/Electromagnetic_radiationhttp://en.wikipedia.org/wiki/Electromagnetic_radiationhttp://en.wikipedia.org/wiki/Electromagnetic_radiationhttp://en.wikipedia.org/wiki/Chemicalshttp://en.wikipedia.org/wiki/Chemicalshttp://en.wikipedia.org/wiki/Chemicalshttp://en.wikipedia.org/wiki/Pathogenhttp://en.wikipedia.org/wiki/Pathogenhttp://en.wikipedia.org/wiki/Pathogenhttp://en.wikipedia.org/wiki/DNA_replicationhttp://en.wikipedia.org/wiki/DNA_replicationhttp://en.wikipedia.org/wiki/DNA_replicationhttp://en.wikipedia.org/wiki/Genetic_disorderhttp://en.wikipedia.org/wiki/Genetic_disorderhttp://en.wikipedia.org/wiki/Genetic_disorderhttp://en.wikipedia.org/wiki/Genomehttp://en.wikipedia.org/wiki/Genomehttp://en.wikipedia.org/wiki/Genomehttp://en.wikipedia.org/wiki/DNA_methylationhttp://en.wikipedia.org/wiki/DNA_methylationhttp://en.wikipedia.org/wiki/DNA_methylationhttp://en.wikipedia.org/wiki/MicroRNAshttp://en.wikipedia.org/wiki/MicroRNAshttp://en.wikipedia.org/wiki/MicroRNAshttp://en.wikipedia.org/wiki/Oncogenehttp://en.wikipedia.org/wiki/Oncogenehttp://en.wikipedia.org/wiki/Oncogenehttp://en.wikipedia.org/wiki/Programmed_cell_deathhttp://en.wikipedia.org/wiki/Programmed_cell_deathhttp://en.wikipedia.org/wiki/Programmed_cell_deathhttp://en.wikipedia.org/wiki/Tumor_suppressor_genehttp://en.wikipedia.org/wiki/Tumor_suppressor_genehttp://en.wikipedia.org/wiki/Tumor_suppressor_genehttp://en.wikipedia.org/wiki/Cell_cyclehttp://en.wikipedia.org/wiki/Cell_cyclehttp://en.wikipedia.org/wiki/Cell_cyclehttp://en.wikipedia.org/wiki/Immune_systemhttp://en.wikipedia.org/wiki/Immune_systemhttp://en.wikipedia.org/wiki/Immune_systemhttp://en.wikipedia.org/wiki/Histologyhttp://en.wikipedia.org/wiki/Histologyhttp://en.wikipedia.org/wiki/Histologyhttp://en.wikipedia.org/wiki/Biopsyhttp://en.wikipedia.org/wiki/Biopsyhttp://en.wikipedia.org/wiki/Biopsyhttp://en.wikipedia.org/wiki/Anatomical_pathologyhttp://en.wikipedia.org/wiki/Anatomical_pathologyhttp://en.wikipedia.org/wiki/Anatomical_pathologyhttp://en.wikipedia.org/wiki/Radiographichttp://en.wikipedia.org/wiki/Radiographichttp://en.wikipedia.org/wiki/Radiographichttp://en.wikipedia.org/wiki/Cancer_staginghttp://en.wikipedia.org/wiki/Cancer_staginghttp://en.wikipedia.org/wiki/Cancer_staginghttp://en.wikipedia.org/wiki/Surgeryhttp://en.wikipedia.org/wiki/Surgeryhttp://en.wikipedia.org/wiki/Surgeryhttp://en.wikipedia.org/wiki/Chemotherapyhttp://en.wikipedia.org/wiki/Chemotherapyhttp://en.wikipedia.org/wiki/Chemotherapyhttp://en.wikipedia.org/wiki/Radiation_therapyhttp://en.wikipedia.org/wiki/Radiation_therapyhttp://en.wikipedia.org/wiki/Radiation_therapyhttp://en.wikipedia.org/wiki/Targeted_therapyhttp://en.wikipedia.org/wiki/Targeted_therapyhttp://en.wikipedia.org/wiki/Targeted_therapyhttp://en.wikipedia.org/wiki/Cancer_staginghttp://en.wikipedia.org/wiki/Cancer_staginghttp://en.wikipedia.org/wiki/Cancer_staginghttp://en.wikipedia.org/wiki/Histologyhttp://en.wikipedia.org/wiki/Histologyhttp://en.wikipedia.org/wiki/Histologyhttp://en.wikipedia.org/wiki/Grading_(tumors)http://en.wikipedia.org/wiki/Grading_(tumors)http://en.wikipedia.org/wiki/Grading_(tumors)http://en.wikipedia.org/wiki/Malignant

8/14/2019 Cancer15

2/2

Male

most common (byoccurrence)

most common (bymortality)

prostate cancer(33%) lung cancer (31%)

lung cancer(13%) prostate cancer (10%)

colorectal cancer(10%) colorectal cancer (10%)

bladder cancer(7%) pancreatic cancer(5%)

cutaneous melanoma(5%)

leukemia (4%)

Female

most common (byoccurrence)

most common (bymortality)

breast cancer(32%) lung cancer (27%)

lung cancer (12%) breast cancer (15%)

colorectal cancer (11%) colorectal cancer (10%)

endometrial cancer(6%) ovarian cancer(6%)

non-Hodgkin lymphoma(4%)

pancreatic cancer (6%)

http://en.wikipedia.org/wiki/Prostate_cancerhttp://en.wikipedia.org/wiki/Lung_cancerhttp://en.wikipedia.org/wiki/Colorectal_cancerhttp://en.wikipedia.org/wiki/Bladder_cancerhttp://en.wikipedia.org/wiki/Pancreatic_cancerhttp://en.wikipedia.org/wiki/Melanomahttp://en.wikipedia.org/wiki/Leukemiahttp://en.wikipedia.org/wiki/Breast_cancerhttp://en.wikipedia.org/wiki/Endometrial_cancerhttp://en.wikipedia.org/wiki/Ovarian_cancerhttp://en.wikipedia.org/wiki/Non-Hodgkin_lymphomahttp://en.wikipedia.org/wiki/Prostate_cancerhttp://en.wikipedia.org/wiki/Prostate_cancerhttp://en.wikipedia.org/wiki/Prostate_cancerhttp://en.wikipedia.org/wiki/Breast_cancerhttp://en.wikipedia.org/wiki/Breast_cancerhttp://en.wikipedia.org/wiki/Breast_cancerhttp://en.wikipedia.org/wiki/Lung_cancerhttp://en.wikipedia.org/wiki/Lung_cancerhttp://en.wikipedia.org/wiki/Lung_cancerhttp://en.wikipedia.org/wiki/Colorectal_cancerhttp://en.wikipedia.org/wiki/Colorectal_cancerhttp://en.wikipedia.org/wiki/Colorectal_cancerhttp://en.wikipedia.org/wiki/Bladder_cancerhttp://en.wikipedia.org/wiki/Bladder_cancerhttp://en.wikipedia.org/wiki/Bladder_cancerhttp://en.wikipedia.org/wiki/Pancreatic_cancerhttp://en.wikipedia.org/wiki/Pancreatic_cancerhttp://en.wikipedia.org/wiki/Pancreatic_cancerhttp://en.wikipedia.org/wiki/Endometrial_cancerhttp://en.wikipedia.org/wiki/Endometrial_cancerhttp://en.wikipedia.org/wiki/Endometrial_cancerhttp://en.wikipedia.org/wiki/Ovarian_cancerhttp://en.wikipedia.org/wiki/Ovarian_cancerhttp://en.wikipedia.org/wiki/Ovarian_cancerhttp://en.wikipedia.org/wiki/Melanomahttp://en.wikipedia.org/wiki/Melanomahttp://en.wikipedia.org/wiki/Melanomahttp://en.wikipedia.org/wiki/Leukemiahttp://en.wikipedia.org/wiki/Leukemiahttp://en.wikipedia.org/wiki/Leukemiahttp://en.wikipedia.org/wiki/Non-Hodgkin_lymphomahttp://en.wikipedia.org/wiki/Non-Hodgkin_lymphomahttp://en.wikipedia.org/wiki/Non-Hodgkin_lymphoma