Cancer i/ˈkænsər/, known medically as a malignant neoplasm, is a broad group of various diseases, all involving unregulated cell growth. In cancer, cells divide and grow uncontrollably, forming malignant tumors, and invade nearby parts of the body. The cancer may also spread to more distant parts of the body through the lymphatic system or bloodstream. Not all tumors are cancerous. Benign tumors do not grow uncontrollably, do not invade neighboring tissues, and do not spread throughout the body. There are over 200 different known cancers that afflict humans.
Determining what causes cancer is complex. Many things are known to increase the risk of cancer, including tobacco use, certain infections, radiation, lack of physical activity, obesity, and environmental pollutants. These can directly damage genes or combine with existing genetic faults within cells to cause the disease. Approximately five to ten percent of cancers are entirely hereditary.
Cancer can be detected in a number of ways, including the presence of certain signs and symptoms, screening tests, or medical imaging. Once a possible cancer is detected it is diagnosed by microscopic examination of a tissue sample. Cancer is usually treated with chemotherapy, radiation therapy and surgery. The chances of surviving the disease vary greatly by the type and location of the cancer and the extent of disease at the start of treatment. While cancer can affect people of all ages, and a few types of cancer are more common in children, the risk of developing cancer generally increases with age. In 2007, cancer caused about 13% of all human deaths worldwide (7.9 million). Rates are rising as more people live to an old age and as mass lifestyle changes occur in the developing world.
Read more about Cancer: Signs and Symptoms, Causes, Pathophysiology, Diagnosis, Prevention, Screening, Management, Prognosis, Epidemiology, History, Society and Culture, Research, In Pregnancy
Other articles related to "cancers, cancer":
... expression or activity of methylation-regulating enzymes has been noted in some types of human cancers, suggesting associations between histone methylation and malignant transformation of cells or formation ... the histone proteins, especially the methylation of the histone H3, in cancer development has been an area of emerging research ... It is now generally accepted that in addition to genetic aberrations, cancer can be initiated by epigenetic changes in which gene expression is altered without genomic abnormalities ...
... Testicular cancer is cancer that develops in the testicles, a part of the male reproductive system ... States, between 7,500 and 8,000 diagnoses of testicular cancer are made each year ... Over his lifetime, a man's risk of testicular cancer is roughly 1 in 250 (0.4%) ...
... Thompson has non-Hodgkin's lymphoma (NHL), a form of cancer ... Thompson's cancer, though currently incurable, is reportedly indolent, the lowest of three grades of NHL ... The cancer is nodal marginal zone lymphoma, a rare form of NHL, that accounts for only one to three percent of all cases ...
... Because cancer is largely a disease of older adults, it is not common in pregnant women ... Cancer affects approximately 1 in 1,000 pregnant women ... The most common cancers found during pregnancy are the same as the most common cancers found in non-pregnant women during childbearing ages breast cancer, cervical cancer, leukemia ...
... radiation and radiation therapy - uncontrolled study—see clinical trial - unconventional cancer treatments—see experimental cancer treatment - undifferentiated—see cellular differentiation - unilateral ...
Famous quotes containing the word cancer:
“I’m beginning to believe that Killer Illiteracy ought to rank near heart disease and cancer as one of the leading causes of death among Americans. What you don’t know can indeed hurt you, and so those who can neither read nor write lead miserable lives, like Richard Wright’s character, Bigger Thomas, born dead with no past or future.”
—Ishmael Reed (b. 1938)
“We “need” cancer because, by the very fact of its incurability, it makes all other diseases, however virulent, not cancer.”
—Gilbert Adair, British author, critic. “Under the Sign of Cancer,” Myths and Memories (1986)
“I wish more and more that health were studied half as much as disease is. Why, with all the endowment of research against cancer is no study made of those who are free from cancer? Why not inquire what foods they eat, what habits of body and mind they cultivate? And why never study animals in health and natural surroundings? why always sickened and in an environment of strangeness and artificiality?”
—Sarah N. Cleghorn (1976–1959)