Revision of the American Joint Committee on Cancer Staging System for Breast Cancer

A Breast Task Force submitted recommended changes and additions to the existing staging system that were (1) evidence-based and/or consistent with widespread clinical consensus about appropriate diagnostic and treatment standards and (2) useful for the uniform accrual of outcome information in national databases.

Major changes included the following: size-based discrimination between micrometastases and isolated tumor cells; identifiers to indicate usage of innovative technical approaches; classification of lymph node status by number of involved axillary lymph nodes; and new classifications for metastasis to the infraclavicular, internal mammary, and supraclavicular lymph nodes.