Prognostic indicators in node-negative early stage breast cancer

With the increasing availability of screening mammography, more women are diagnosed as having breast cancers at an early, node-negative stage. The majority of these patients would be cured with total mastectomy or breast conservation treatment. However, about 30% of the patients would have recurrence of disease in distant sites. In recent randomized clinical trials, adjuvant systemic therapy has been shown to reduce the rate of recurrence in these patients. Proper selection of patients for adjuvant therapy is necessary to avoid exposing many patients with low risk of recurrence to treatments for whom the benefit is not justified by the toxicity and the cost. In this article, we review the clinical and pathologic prognostic factors in early stage, node-negative breast cancer patients, including tumor size, nuclear and histologic grades, estrogen and progesterone receptors, menopausal status, proliferative rate, HER2/neu oncogene amplification, and cathepsin D level. Favorable prognostic factors include tumor size less than or equal to 2 cm, low nuclear and histologic grades, low S-phase fraction, diploid state, low cathepsin-D level, and positive estrogen and progesterone receptor status. The value of HER-2/neu oncogene overexpression is controversial, and further studies are needed to define its role as a prognostic factor in patients with node-negative breast cancer. Based on these prognostic factors, it is possible to identify subsets of patients who have a low risk of recurrence and would not benefit significantly from adjuvant systemic therapy.