Overview of SEER

The SEER Program is an epidemiologic surveillance system consisting of population-based tumor registries designed to track cancer incidence and survival in the United States. Collection of the SEER data began on January 1, 1973. The registries routinely collect information on newly diagnosed cancer patients residing in geographically defined areas.

The registries collect information about all primary cancers that a person may develop. The SEER data contain information about an incident cancer diagnosis and cancer-directed surgery and radiation therapy provided for first course of treatment. The registries collect information about all primary cancers that a person may develop. The SEER data do not capture information about surgery and radiation provided past four months of diagnosis, nor is there information about recurrence or metastasis that is detected subsequent to the initial diagnosis.

For more information about the SEER program and data, please see the SEER homepageExternal Web Site Policy.

The SEER data file

The cancer registry data released as part of SEER-MHOS are included in a customized file known as the SEER-MHOS Cancer file. This file is an expanded SEER Research Plus file (e.g., it includes additional information variables (e.g., on place of residence, registry-determined first course of therapy and biomarker test results) not typically released by SEER, but is limited to Medicare beneficiaries. As such, the SEER-MHOS Cancer file includes one record per tumor diagnosed among persons in the SEER database who have been matched with Medicare enrollment records. Each record includes information about the person (e.g., age at diagnosis, sex, race, ethnicity, and marital status) and the tumor (e.g., site, stage, histology, and grade). Refer to the 5-digit Site Recode Web Site PolicyExternal Web Site Policy for the list of cancers available.

Last Updated: 23 Nov, 2021