Breast cancer adjuvant therapy

Combined modality trials in early breast cancer have been underway since the 1960s and results are available to indicate varying degrees of success in Stage I and II. The trials have involved more than 29,000 women in 61 randomized trials. The recommendations can be summarized by stage, estrogen receptor (ER) status, and menopausal status. In Stage II patients, chemotherapy has an impact on disease mortality for ER-positive and ER-negative premenopausal women and possibly ER-negative postmenopausal patients. In postmenopausal Stage II ER-positive patients, tamoxifen given for more than 2 years has a beneficial effect on survival. In node-negative patients, the major effects have been on improving disease-free survival (DFS) rather than overall survival. Tamoxifen has a positive effect in ER-positive patients while chemotherapy benefits ER-negative patients. In at least one trial chemotherapy benefitted women with ER-positive tumors, both premenopausal and postmenopausal, with lesions larger than 3.0 cm. Ongoing trials are designed to answer questions regarding optimal therapy for varying subsets including those tumors in which ER cannot be measured. New prognostic features used to determine therapy include flow cytometry studies of DNA synthesis and oncogene expression.