Staging

A short definition for staging is "the grouping of cases into broad categories based on extent of disease." Elements used in any staging system are the primary tumor site, tumor size, multiplicity (number of tumors), depth of invasion and extension to regional or distant tissues, involvement of regional lymph nodes, and distant metastases. In recent years, the addition of biomarkers have also been added that help with the staging of breast cancer.

See Staging a Cancer Case | SEER Training for more information on the basics of staging.

Document all staging details (EOD Primary Tumor, EOD Regional Nodes, EOD Mets, Mets at Dx fields [Bone, Brain, Lung, Liver, Distant Lymph Nodes, Other and Summary Stage] in NAACCR Item # 2600: Text-Staging. This is addition to documenting information from the pathology report, imaging, or other sources.

For more information on staging

• See Extent of Disease 2018 (EOD 2018) | SEER Training website for general information on EOD (including why SEER collects Extent of Disease).
• See Extent of Disease (EOD) 2018 for the EOD general instructions.
• See SEER*RSA for the current version of the breast schema for EOD.
• See Summary Stage 2018 (SS2018) | SEER Training website for general information on Summary Stage.
• See American Joint Committee on Cancer (AJCC) for general information on AJCC Staging or Training.

Updated: January 10, 2025