A revised staging system for breast cancer.

The sixth edition of the American Joint Committee on Cancer (AJCC) staging system for invasive and in situ breast cancer has significant implications for the maximization of patient care. These evidence-based standards now reflect current standards of care and practice. Guidelines for a more uniform and accurate primary tumor analysis, including grade, size, and histologic classification are now provided, as well as standards for diagnosis and handling of microinvasion, multiple ipsilateral or contralateral carcinomas, and inflammatory carcinomas. The reporting of nodal metastasis has been refined and the characterization of metastatic disease has been revised. These revised guidelines should now be used for patient categorization, data gathering, and clinical categorization. National adaptation of these changes should greatly facilitate inter- and intrainstitutional standardization and data gathering.