Cancer: A term for diseases in which abnormal cells divide
without control. Cancer cells can invade nearby tissues and can
spread through the bloodstream and lymphatic system to other parts
of the body.
Cancer incidence: The number of new cases of cancer reported in a specified period of time (e.g., year) divided by the number of persons in the population (e.g., county, region, state, etc.) during this period.
Confidentiality: The Missouri Cancer Registry takes great care to protect the confidentiality of cancer patients. To minimize the possibility of inadvertent disclosure at the county level, three cancer incidence MICAs have been developed. Two show state and Behavioral Risk Factor Surveillance System (BRFSS) region data and one shows state, BRFSS region, and county data. The first two show demographic and clinical detail, while in the latter only sex, stage, major cancer sites and aggregated years are shown.
Ethnicity: Hispanic origin is a required field according to SEER standards, but due to the large number of cases recorded as "unknown ethnicity," ethnicity has not yet been included as a Cancer MICA category. Persons of Hispanic birth or ancestry who are not definitely of African-American, Native American or other designated race are classifed as white.
In situ: In place; confined to one area; non-invasive. A very early stage of cancer.
Invasive cancer: Cancer that has spread beyond the layer of cells where it first developed to involve additional tissues.
Localized: 1) The cancer is limited to the primary site; 2) Cancer that is confined to the place where it started; that is, it has not spread to adjacent areas/tissues or distant parts of the body.
Regional: The cancer has spread from its original site to adjacent organs or tissues and/or regional lymph nodes but not to distant sites such as other organs.
Distant: The cancer has spread to distant organs or nodes, i.e., tumor cells have broken away from the primary tumor, have traveled to other parts of the body and have begun to grow in the new location.
Unknown: The stage of disease is unknown but is assumed to be invasive.
Grading is done to evaluate and report the degree of a cancer's differentiation.
Differentiation: The normal process through which cells mature so they can carry out the jobs they were meant to do. Cancer cells are less differentiated than normal cells. In cancer, differentiation refers to how mature (developed) the cancer cells are in a tumor. Differentiated tumor cells resemble normal cells and tend to grow and spread at a slower rate than undifferentiated or poorly-differentiated tumor cells, which lack the structure and function of normal cells and grow uncontrollably.
T-cells: white blood cells made in the thymus gland. They produce lymphokines and play a large role in the immune response against viruses, transplanted organs and tissues, and cancer cells. (specific to leukemias and lymphomas)
B-cells: White blood cells that are involved in making antibodies. Specific to leukemias and lymphomas.
Null cell: A non-T, non-B cell specific to leukemias and lymphomas.
Cancers are classified according to the Site Recode ICD-O-3/WHO 2008 Definition, available at http://seer.cancer.gov/siterecode/icdo3_dwhoheme/index.html.
Buccal cavity: The portion of the oral cavity bounded by the lips, cheeks, and gums.
Lymphoma: 1)Cancer of the lymphatic system, a network of thin vessels and nodes throughout the body. Its function is to fight infection. Lymphoma involves a type of white blood cells called lymphocytes. The two main types of lymphoma are Hodgkin's disease and non-Hodgkin's lymphoma. The treatment methods for these two types of lymphomas are very different. 2) Cancer that arises in cells of the lymphatic system.
Myeloma: Cancer that arises in plasma cells, a type of white blood cell.
Leukemia: 1) Cancer of blood-forming tissue. 2) Cancer of the blood or blood-forming organs. People with leukemia often have a noticeable increase in white blood cells (leukocytes).
Ill-defined & unspecified: Ill-defined or unspecified tissue of origin.
Note: the definitions above were adapted from the following sources.
National Cancer Institute web site dictionary; American Cancer Society web site glossary; A Dictionary of Epidemiology by John M. Last, 3rd edition; SEER Book 2; and the Compact American Medical Dictionary, 1998.