Welcome to the SEER*RSA (Registrar Staging Assistant) website. This site is intended for use by cancer registrars to help with cancer stage assignment and the coding of predictive and prognostic factors.


The data on this site can be used to help you do the following:

  • Determine the Union for International Cancer Control (UICC) TNM 7th edition stage and Collaborative Stage v.02.05.50.
    UICC 7th edition and AJCC 7th edition TNM categories and stage groups are very similar; however, there are some differences between UICC 7th edition and AJCC 7th edition.

  • Code predictive and prognostic factors.

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



Beginning with cancer cases diagnosed January 1, 2016, 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 continue to collect stage using the CS system.

SEER*RSA references the UICC TNM 7th edition classification. The licensing and use of the AJCC TNM tables and definitions, with additional notes for registrars as an integral component of SEER*RSA, are still under discussion. The UICC 7th edition staging classification will continue to be a component of SEER*RSA in the future because the UICC TNM 7th edition represents the international approach to cancer staging and because SEER data are combined with international surveillance data. Once the use agreement has been finalized between AJCC and NCI, the AJCC staging tables will also be incorporated.

All of the standard setting organizations agreed to continue collection of predictive and prognostic factors through the CS Site Specific Factors (SSFs) as they were collected prior to 1/1/2016. We will continue to use the CS data and variable definitions for SSFs until there has been a thorough review of the predictive and prognostic factors to determine which are clinically relevant, available to be collected by cancer registrars, and until the best NAACCR data structure for collection of the SSFs has been established.