Welcome to the SEER*RSA (SEER Registrar Staging Assistant) website. This site is to be used by cancer registrars who abstract and code extent of disease information, and important site-specific predictive and prognostic factors. Instructional manuals are provided elsewhere.


Use the information on this site to:

  • Code EOD 2018 data items

  • Code Summary Stage 2018

  • Code Site-Specific Data Items (SSDIs)

  • Code TNM or CS data items, as appropriate, for 2017 and prior cases

In addition to this site, SEER*RSA data are provided via both an API and software libraries. To learn more, choose from the following links:



For cancer cases diagnosed from January 1, 2016 through December 31, 2017, cancer registries in the United States transitioned from collecting cancer stage information using CS to collecting stage using the TNM classification. Approximately one half of registries reporting to the NCI SEER program continued collecting stage using the CS system.

For these years, SEER*RSA references the UICC TNM 7th edition classification. UICC TNM 7th edition represents the international approach to cancer staging and SEER data are combined with international surveillance data.

All of the standard setting organizations continued collection of predictive and prognostic factors through the CS Site Specific Factors (SSFs) for 2016 and 2017.

For cancer cases diagnosed January 1, 2018 and later, the NCI SEER program will collect Extent of Disease (EOD) revised for 2018 and Summary Stage 2018. The schemas have been developed to be compatible with the AJCC 8th Edition chapter definitions.

All of the standard setting organizations will collect the predictive and prognostic factors through Site Specific Data Items (SSDIs). Unlike the SSFs, these data items have formats and code structures specific to the data item.

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