Incorporating Biology Into Breast Cancer Staging: American Joint Committee on Cancer, Eighth Edition, Revisions and Beyond

The American Joint Committee on Cancer (AJCC) staging system historically has assigned stage on the basis of the size of a patient’s primary tumor, the presence and extent of lymph node disease, and the presence or absence of distant metastasis. The TNM categories are determined, and a corresponding disease stage is defined. At the time of diagnosis, a clinical stage is assigned on the basis of the presenting history, physical examination, and any imaging studies obtained. A pathologic stage, which takes into account the pathologic assessment of the resected tumor and lymph nodes, is assigned after surgery. Although the primary goal of staging is to inform prognosis, staging can also be used to (1) determine a treatment plan, (2) facilitate conversation between providers, (3) identify patient groups for clinical trial participation, and (4) permit standardized data collection that allows for evaluation of the impact of changes in clinical practice. Since the initial publication of the AJCC staging manual in 1977, the breast cancer staging system has been revised multiple times to reflect advances in diagnosis and treatment. These prior revisions have largely reflected improvements in imaging, surgery, and pathology that have resulted in earlier detection and more refined determination of the disease extent. Previous changes have not accounted for biologic factors like grade, estrogen receptor (ER) status, progesterone receptor (PR) status, and HER2 status, which have predictive and prognostic value. Grade and ER, PR, and HER2 status are determined routinely during the pathologic assessment of breast tumors.1,2 The selection of treatment is influenced by these factors, and risk of recurrence after treatment within each stage varies according to these features. The response to treatment also is influenced by these factors; therefore, prognosis within each stage varies according to these features.3-7 Recognizing this, the panel (which included E.A.M.) that was convened to revise the AJCC staging system prioritized incorporation of biologic factors into the revisions for the eighth edition. INCLUSION OF BIOLOGIC FACTORS IN BREAST CANCER STAGING Section: ChooseTop of pageAbstractINCLUSION OF BIOLOGIC FAC... <