One hundred thirty-one premenopausal women with metastatic breast cancer who had received no prior systemic treatment for metastases were entered on study. Patients without prior chemotherapy with estrogen receptor (ER)-positive and ER-unknown disease were randomized to receive cyclophosphamide, Adriamycin (Adria Laboratories, Columbus, OH), and 5-fluorouracil (CAF) or surgical oophorectomy followed directly by CAF (O + CAF). ER-negative patients without prior chemotherapy were directly assigned to treatment with CAF. Among randomized patients 83% have responded, and 37% have achieved a complete remission. Among ER-negative patients the complete response rate was 38%, and the complete plus partial response rate was 70%. Characteristics significantly associated with a longer time to treatment failure were age 45 or over, one or two organ sites, and performance status O. The median survival time of ER-positive patients treated with CAF is 29 months, and with O + CAF it has not yet been reached, whereas for ER-unknown patients the equivalent survival times are 41 months and 43 months respectively. For ER-negative patients treated with CAF the median survival time is 17 months. Characteristics associated with significantly longer survival among randomized patients were age 35 or over (P = .009) and only one or two organ sites involved (P = .02). Neither treatment (P = .33) nor ER status (P = .70) was significant.