Prognostic and predictive factors in the adjuvant treatment of breast cancer.

The selection of systemic adjuvant therapy should be based on the appropriate prognostic and predictive factors. The established prognostic factors currently used in cases of primary breast cancer include axillary lymph node involvement, histologic subtype, tumor size, nuclear or histologic grade, estrogen (ER) and progesterone receptor (PR) status and proliferative index. Adjuvant chemotherapy has had an impact on the management of node-positive breast cancer, while the St. Gallen recommendations were established for postoperative adjuvant therapy for node-negative breast cancer. However, there is some contention regarding the histological (or nuclear) grading systems among different pathologists. With regard to biological measurements, the most useful prognostic/predictive factors are hormone receptor status and HER-2 overexpression. ER and PR status can be used to establish the necessity of hormone therapy in the adjuvant setting. If the anti-HER-2 antibody and/or antiangiogenic agents are introduced into the adjuvant setting in the near future, determination of these factors is also recommended.