Breast Cancer Staging
The American Joint Committee on Cancer stages breast malignancies according to the TNM system that describes characteristics of the primary tumor, involvement of regional lymph nodes, and distant metastasis. Surgical stage helps determine the appropriate types of therapy (Tables 31.4 and 31.5).
In addition to stage, receptor status is another impor-tant indicator of breast cancer prognosis. Expression ofestrogen or progesterone receptors positively affects prognosis. The Her2/neu (or c-erb-B2) is an oncogene encoding a membrane-bound growth-factor receptor. Overexpression confers a poor prognosis and is noted in 20% to 30% of invasive ductal cancers.