Cyclophosphamide, methotrexate, and fluorouracil versus tamoxifen plus ovarian suppression as adjuvant treatment of estrogen receptor-positive pre-/perimenopausal breast cancer patients: Results of the italian breast cancer adjuvant study group O2 randomized trial

Purpose: To compare the efficacy of chemotherapy versus that of tamoxifen plus ovarian suppression in pre-/perimenopausal estrogen receptor-positive patients with early breast cancer. Patients and Methods: Patients were randomly assigned to receive either six cycles of a standard regimen of cyclophosphamide 100 mg/m² orally days 1 to 14, methotrexate 40 mg/m² intravenously (IV) days 1 and 8, and fluorouracil 600 mg/m² IV days 1 and 8 (CMF), with all drugs restarted on day 29, or 5 years of tamoxifen, 30 mg/d, plus ovarian suppression with surgical oophorectomy, ovarian irradiation, or monthly goserelin 3.6-mg injections. Disease-free survival was the main study end point. Overall survival and toxicity were additional end points. Results: Between 1989 and 1997, 120 patients were assisted to CMF and 124 to tamoxifen and ovarian suppression (oophorectomy, n = 6; ovarian irradiation, n = 31; and goserelin injections, n = 87). At the time of analysis (median follow-up time, 76 months; range, 9 to 121 months), 82 patients had relapsed and 39 had died. No difference between groups had emerged with respect to either disease-free or overall survival. Treatment were comparable even in respect to age, tumor size, and nodal status, although a nonsignificant trend favored patients with poorly differentiated tumors treated with CMF. Leukopenia, nausea, vomiting, stomatitis, and alopecia were significantly more common in patients treated with CMF. There were few patients who developed benign gynecologic changes in either group, and numbers were comparable. Conclusion: The combination of tamoxifen with ovarian suppression seems to be safe and to yield comparable results relative to standard CMF.