SEER collects cancer incidence data from population-based cancer registries covering approximately 34.6 percent of the U.S. population. The SEER registries collect data on patient demographics, primary tumor site, tumor morphology, stage at diagnosis, and first course of treatment, and they follow up with patients for vital status.

How to Access SEER Data

SEER Research Data

SEER releases a standard set of research data every spring based on the previous November’s submission of data from the registries. ┬áThe SEER Research Data includes the fields and variables SEER has made available to the public with a signed SEER Data-Use Agreement form.

For access options and datasets included in the release, see Accessing the Data.

Number of Records in the SEER Research Data

The numbers provided in the table below are for the most recent SEER research data release and the previous release. Malignant and In Situ cases are defined using the SEER Behavior Recode for Analysis. Starting with the November 2018 Submission, the SEER Research Data include cases diagnosed starting with 1975 instead of 1973, and three new registries were added to a SEER 21 databases covering 2000-2016 cases.

SEER 18 Databases*
  All Cases ** Malignant Cases Malignant +
In Situ Cases
1975-2016 Data (Nov 2018 Submission) 10,450,709 9,428,053 10,146,162
1975-2015 Data (Nov 2017 Submission) 9,934,630 8,985,826 9,659,955
Increase from 2017 to 2018 Submission 516,079 442,227 486,207
Number of 2016 cases for SEER 18 497,931 430,095 473,440
SEER 21 Databases*
  All Cases ** Malignant Cases Malignant +
In Situ Cases
2000-2016 Data (Nov 2018 Submission) 10,411,062 9,201,572 10,001,075
2000-2016 for 3 New Registries (ID, NY, MA) 2,814,195 2,490,874 2,703,498
Number of 2016 cases for SEER 21 672,996 582,352 640,486

* Registries included in the SEER 18 and SEER 21 data are defined in Registry Groupings in SEER Data and Statistics.
** All Cases includes benign and borderline brain and CNS tumors, cases coded as no longer reportable in ICD-O-3 and as only malignant in ICD-O-3 or 2010+. See SEER Behavior Recode for more information.

Specialized Databases

There are additional fields that SEER collects and makes available through databases that are not part of the standard SEER Research Data files. SEER makes these available in specialized databases that can be accessed through the SEER*Stat software with additional approvals.

For more information, refer to the list of Specialized Databases.

SEER Database Details