Common Terms in Cancer Data

Age-adjusted rate - Cancer rates vary with age, and populations vary by their age distributions. Age adjustment allows for comparison of rates between different populations with different age structure. The "effect of age" is no longer present upon age-adjustment. Age-adjusted rates are calculated using the age distribution of the 2000 US standard population, and they are usually expressed per 100,000 population.

Age-specific rate - The number of new cases diagnosed per 100,000 individuals over a specific time period for a specific age group.

Cancer site - The body organ or system where cancer originates; the anatomical site of origin.

Centers for Disease Control (CDC) - Located in Atlanta, GA, the CDC is an agency of the Department of Health and Human Services. The CDC serves as the national focus for developing and applying disease prevention and control, environmental health, and health promotion and education activities designed to improve the health of people of the United States.

Crude rate - The number of new cases or deaths during a specific time period per 100,000 individuals. There is no consideration (adjustment) given to the age factor.

Distant stage - Classification of cancer spread beyond adjacent organs or tissues, and/or metastasis to distant lymph nodes or tissues.

Early stage - Grouping which includes in situ and localized stages of disease.

Five-year survival - The percentage of people with a given cancer who are expected to survive five years or longer with the disease.

In situ stage - Classification for pre-invasive malignancies, those that do not invade the basement membrane.

Incidence - The number of new cases diagnosed during a specific time period (i.e. one year).

Late stage - Grouping which includes regional and distant stages of disease.

Localized stage - Classification for invasive malignancies that are confined to the organ of origin.

Metastasis - Movement of disease from one organ or part to another not directly connected.

Mortality - The number of deaths occurring during a specific time period. Diagnosis may have occurred prior to that specific time period.

National Program of Cancer Registries (NPCR) - Funded by the CDC, the NPCR is a population-based system of cancer registries established in 1992 by the Central Cancer Registries Amendment Act (Public Law 102-515). When fully implemented, programs funded by the NPCR will collect data on cancer for 96% of the US population.

Prevalence - A measure of the proportion of persons in a population with a certain disease at a given time. The SCCCR does not collect prevalence.

Regional stage - Classification for cancer spread by direct extension to adjacent organs or tissues, and/or spread to lymph nodes considered regional to the organ of origin, but no further spread has occurred.

Risk factor - Anything that increases a person's chances of getting a disease. Examples include smoking, diet, and age.

Surveillance, Epidemiology and End Results (SEER) - Program of the National Cancer Institute that collects and publishes cancer incidence and survival data from 19 population-based cancer registries.

Stage at diagnosis - The extent of disease spread from the organ of origin at time of diagnosis. The SCCCR uses the SEER General Summary Staging System. This system includes five stages: in situ, localized, regional, distant, and unstaged. In situ and localized are classified as "early stage." Regional and distant are considered "late stage." Cancers diagnosed as in situ are considered pre-invasive. Localized, regional, and distant staged cancers are invasive.

Unstaged - Classification resulting from insufficient information available to determine stage of disease at diagnosis.

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Cancer Health Statistics & Reports