Combined chemohormonal therapy is an attractive therapeutic strategy for the treatment of Stage IV breast cancer. Between 1977 and 1979, the authors evaluated a new chemohormonal therapy program in 63 evaluable women with advanced breast cancer who previously had not received cytotoxic chemotherapy or tamoxifen. The chemohormonal therapy consisted of 21- to 28-day cycles of tamoxifen (10 mg orally twice daily), Adriamycin (doxorubicin) (40 mg/m2 intravenously on day 1) and cyclophosphamide (200 mg/m2 orally on days 3-6) (TAC). Objective responses were observed in 82% of the patients (22% complete response, 60% partial response). With a median follow-up of 104 weeks (2 years), the median relapse-free survival for the 52 responding patients was 80 weeks. The median survival for the entire group of 63 patients was 118 weeks. Eleven pretreatment patient characteristics were evaluated via univariate and multivariate analysis to determine their effect on response and survival. Prognostic factors with a significant association with longer survivals were as follows: a lack of soft tissue involvement, a lack of pleural involvement, and a long disease-free interval (DFI). Estrogen receptor (ER)-unknown patients, being composed primarily of postmenopausal patients with a long DFI and single-organ involvement (primarily bone), comprised 62% of the patient population and achieved a survival similar to the smaller number of ER-positive patients and was superior to the survival of ER-negative patients. Toxicities were recorded on all patients and overall the treatment was well tolerated. Combined chemohormonal therapy with TAC resulted in a high objective response rate and a long median survival. This study would support additional trials of chemohormonal therapy in patients with ER-positive tumors or in those whose tumors are likely to be ER-positive (e.g., postmenopausal patients with long DFIs).