|1.||any type of malignant growth or tumour, caused by abnormal and uncontrolled cell division: it may spread through the lymphatic system or blood stream to other parts of the body|
|2.||the condition resulting from this|
|3.||an evil influence that spreads dangerously|
|[C14: from Latin: crab, a creeping tumour; related to Greek karkinos crab, Sanskrit karkata]|
|Cancer (ˈkænsə, kænˈsɪərɪən)|
|—n , Latin genitive Cancri|
|1.||astronomy a small faint zodiacal constellation in the N hemisphere, lying between Gemini and Leo on the ecliptic and containing the star cluster Praesepe|
|a. Also called: the Crab the fourth sign of the zodiac, symbol ♋, having a cardinal water classification and ruled by the moon. The sun is in this sign between about June 21 and July 22|
|b. Also called: Moonchild a person born during a period when the sun is in this sign|
|3.||tropic of Cancer See tropic|
|4.||astrology born under or characteristic of Cancer|
|1.||(sometimes capital) either of the parallel lines of latitude at about 23½°N (tropic of Cancer) and 23½°S (tropic of Capricorn) of the equator|
|2.||(often capital) the tropics that part of the earth's surface between the tropics of Cancer and Capricorn; the Torrid Zone|
|3.||astronomy either of the two parallel circles on the celestial sphere having the same latitudes and names as the corresponding lines on the earth|
|4.||a less common word for tropical|
|[C14: from Late Latin tropicus belonging to a turn, from Greek tropikos, from tropos a turn; from the ancient belief that the sun turned back at the solstices]|
cancer can·cer (kān'sər)
Abbr. CA Any of various malignant neoplasms characterized by the proliferation of anaplastic cells that tend to invade surrounding tissue and metastasize to new body sites.
The pathological condition characterized by such growths.
|cancer (kān'sər) Pronunciation Key
Our Living Language : The human immune system often fights off stray cancer cells just as it does bacteria and viruses. However, when cancer cells establish themselves in the body with their own blood supply and begin replicating out of control, cancer becomes a threatening neoplasm, or tumor. It takes a minimum of one billion cancer cells for a neoplasm to be detectable by conventional radiology and physical examinations. Cancer, which represents more than 100 separate diseases, destroys tissues and organs through invasive growth in a particular part of the body and by metastasizing to distant tissues and organs through the bloodstream or lymph system. Heredity, lifestyle habits (such as smoking), and a person's exposure to certain viruses, toxic chemicals, and excessive radiation can trigger genetic changes that affect cell growth. The altered genes, or oncogenes, direct cells to multiply abnormally, thereby taking on the aggressive and destructive characteristics of cancer. Treatments such as surgery, chemotherapy, and radiation are effective with many cancers, but they also end up killing healthy cells. Gene therapy attempts to correct the faulty DNA that causes the uncontrolled growth of cancer cells. Researchers are investigating other treatments, such as immunotherapy (the stimulation of the body's natural defenses), vectorization (aiming chemicals specifically at cancer cells), and nanotechnology (targeting cancer cells with minute objects the size of atoms).
A faint constellation in the Northern Hemisphere near Leo and Gemini. Cancer (the Crab) is the fourth sign of the zodiac.
|tropic (trŏp'ĭk) Pronunciation Key
|Tropic of Cancer
The parallel of latitude approximately 23°27' north. It forms the boundary between the Torrid and North Temperate zones.
A disease characterized by rapid growth of cells in the body, often in the form of a tumor. Cancer is invasive — that is, it can spread to surrounding tissues. Although this disease is a leading cause of death in the United States, research has provided considerable insight into its many causes (which may include diet, viruses, or environmental factors) and options for treatment (which include radiation, chemotherapy, surgery, and possibly gene therapy).
Note: The term cancer is often used to describe a nonmedical condition that is undesirable, destructive, and invasive: “Watergate was a cancer on the presidency.”