The recently developed TNM-based breast cancer staging.

Abstract

This study details the modifications made to the Tumor–Node–Metastasis (TNM)-based staging of breast tumors by the most recent, eighth editions of the pertinent publications from the American Joint Committee on Cancer (AJCC) and the Union for International Cancer Control (UICC). After providing some background information on TNM's status as the standard language for cancer staging and associated activities, such as cancer treatment and registration, it summarizes the changes and goes over some key points that pathologists should be aware of. It also lists and discusses the differences between the publications and diagnostic procedures that are based on them. Although not included in the UICC TNM classification of malignant tumors, a part is devoted to the prognostic stages of breast carcinomas that were presented in the AJCC Cancer Staging Manual. The review concludes with some final thoughts that raise the possibility of a loss of the common staging language. These issues include multifocal tumors, larger lymph node metastases identified by molecular methods, and the heterogeneous prognosis of M1-defined stage IV disease, all of which the authors believe are not adequately covered by TNM.