Cancer Dictionary – C
calcification Deposits of calcium in the tissues. Calcification in the breast can be seen on a mammogram, but cannot be detected by touch. There are two types of breast calcification, macrocalcification and microcalcification. Macrocalcifications are large deposits and are usually not related to cancer. Microcalcifications are specks of calcium that may be found in an area of rapidly dividing cells. Many microcalcifications clustered together may be a sign of cancer.
Calcified Pleural Plaques Fibrous or partially calcified thickened area which can be seen on X-raysof individuals exposed to asbestos. They do not become malignant or cause other lung impairment
cancer (KAN-ser) A term for diseases in which abnormal cells divide without control. Cancer cells can invade nearby tissues and can spread to other parts of the body through the blood and lymph systems. There are several main types of cancer. Carcinoma is cancer that begins in the skin or in tissues that line or cover internal organs. Sarcoma is cancer that begins in bone, cartilage, fat, muscle, blood vessels, or other connective or supportive tissue. Leukemia is cancer that starts in blood-forming tissue such as the bone marrow, and causes large numbers of abnormal blood cells to be produced and enter the blood. Lymphoma and multiple myeloma are cancers that begin in the cells of the immune system. Central nervous system cancers are cancers that begin in the tissues of the brain and spinal cord.
cancer antigen 125 (KAN-ser AN-tih-jen…) A substance that may be found in high amounts in the blood of patients with certain types of cancer, including ovarian cancer. Cancer antigen 125 levels may also help monitor how well cancer treatments are working or if cancer has come back. Also called CA-125.
cancer cluster (KAN-ser KLUS-ter) The occurrence of a larger-than-expected number of cases of cancer within a group of people in a geographic area over a period of time.
Cancer Information Service CIS. The Cancer Information Service is the National Cancer Institute’s link to the public, interpreting and explaining research findings in a clear and understandable manner, and providing personalized responses to specific questions about cancer. Access the CIS by calling 1-800-4-CANCER (1-800-422-6237)
carcinogen (kar-SIN-o-jin) Any substance that causes cancer. Known carcinogens include asbestos and benzene
carcinogenesis The process by which normal cells are transformed into cancer cells.
carcinoid (KAR-sih-noyd) A slow-growing type of tumor usually found in the gastrointestinal system (most often in the appendix), and sometimes in the lungs or other sites. Carcinoid tumors may spread to the liver or other sites in the body, and they may secrete substances such as serotonin or prostaglandins, causing carcinoid syndrome.
carcinoma (KAR-sih-NOH-muh) Cancer that begins in the skin or in tissues that line or cover internal organs.
carcinoma of unknown primary (KAR-sih-NOH-muh…) CUP. A case in which cancer cells are found in the body, but the place where the cells first started growing (the origin or primary site) cannot be determined. Also called cancer of unknown primary origin and CUP.
carcinomatosis (KAR-sih-NOH-muh-TOH-sis) A condition in which cancer is spread widely throughout the body, or, in some cases, to a relatively large region of the body. Also called carcinosis.
carcinosis A condition in which cancer is spread widely throughout the body, or, in some cases, to a relatively large region of the body. Also called carcinomatosis.
case-control study A study that compares two groups of people: those with the disease or condition under study (cases) and a very similar group of people who do not have the disease or condition (controls). Researchers study the medical and lifestyle histories of the people in each group to learn what factors may be associated with the disease or condition. For example, one group may have been exposed to a particular substance that the other was not. Also called a retrospective study.
chemoimmunotherapy (KEE-moh-IH-myoo-noh-THAYR-uh-pee) Chemotherapy combined with immunotherapy. Chemotherapy uses different drugs to kill or slow the growth of cancer cells; immunotherapy uses treatments to stimulate or restore the ability of the immune system to fight cancer.
chemoprevention (KEE-mo-pre-VEN-shun) The use of drugs, vitamins, or other agents to try to reduce the risk of, or delay the development or recurrence of, cancer.
chemoprevention study In cancer prevention, a clinical trial that studies whether taking certain medicines, vitamins, minerals, or food supplements can prevent cancer. Also called agent study.
chemoprotective A quality of some drugs used in cancer treatment. Chemoprotective agents protect healthy tissue from the toxic effects of anticancer drugs.
chemoradiation Treatment that combines chemotherapy with radiation therapy. Also called chemoradiotherapy.
chemoradiotherapy (KEE-moh-RAY-dee-oh-THAYR-uh-pee) Treatment that combines chemotherapy with radiation therapy. Also called chemoradiation.
chemosensitivity The susceptibility of tumor cells to the cell-killing effects of anticancer drugs.
chemosensitivity assay A laboratory test that measures the number of tumor cells that are killed by a cancer drug. The test is done after the tumor cells are removed from the body. A chemosensitivity assay may help in choosing the best drug or drugs for the cancer being treated.
chromosome (KROH-muh-some) Part of a cell that contains genetic information. Except for sperm and eggs, all human cells contain 46 chromosomes.
chronic (KRAHN-ik) A disease or condition that persists or progresses over a long period of time.
Chromosomal Aberrations An abnormality of chromosome number or structure. Chromosome abnormalities usually occur when there is an error incell division
Chromosomal Translocation When a portion of one chromosome is transferred to another chromosome.
clinical study A type of research study that tests how well new medical approaches work in people. These studies test new methods of screening, prevention, diagnosis, or treatment of a disease. Also called a clinical trial.
clinical trial A type of research study that tests how well new medical approaches work in people. These studies test new methods of screening, prevention, diagnosis, or treatment of a disease. Also called a clinical study.
cohort (koh-HORT) A group of individuals who share a common trait, such as birth year. In medicine, a cohort is a group that is part of a clinical trial or study and is observed over a period of time.
cohort study A research study that compares a particular outcome (such as lung cancer) in groups of individuals who are alike in many ways but differ by a certain characteristic (for example, female nurses who smoke compared with those who do not smoke).
core biopsy (… BY-op-see) The removal of a tissue sample with a wide needle for examination under a microscope.
cytology (sy-TAH-loh-jee) The study of cells using a microscope.
cytogenetics (SY-toh-jeh-NEH-tix) The study of chromosomes and chromosomal abnormalities.