Staging Systems


The Surveillance, Epidemiology and End Results (SEER) Program of the National Cancer Institute collects cancer data from designated populated-based cancer registries in various areas of the country. There are two staging classifications developed by SEER: extent of disease and summary stage. Extent of disease (EOD) coding is required for all SEER programs funded through the National Cancer Institute.

The Commission on Cancer (CoCExternal Website Policy) of the American College of Surgeons requires that the American Joint Committee on Cancer (AJCCExternal Website Policy) staging system be completed on all applicable sites and histologies. The COC and NPCR require summary staging on the sites or histologies not included in AJCC staging.

General Guidelines for Staging all Schemes

  • Stage grouping can only be applied to cancers that are alike in site, histology, or both.
  • Accurate and complete assessment of the cancer is necessary before staging.
  • Rule out distant disease first. When metastatic disease is documented, there may be no need to look for information about the primary tumor and regional lymph node status.
  • A few cases are unstageable. The "unstageable" category should be assigned only after all efforts to identify the extent of the disease have been exhausted or the site or histology does not meet criteria for staging.
  • It is mandatory to stage uniformly using the same staging classification in order to compare data or results.
  • If staging information is unclear, it is important to seek further information in order to ensure the quality of data.