Adjuvant CMFVP versus adjuvant CMFVP plus ovariectomy for premenopausal, node-positive, and estrogen receptor-positive breast cancer patients: a Southwest Oncology Group study

Abstract

Purpose: To determine whether the addition of surgical ovariectomy to standard chemotherapy prolongs disease-free survival (DFS) and overall survival in premenopausal patients with estrogen receptor (ER)-positive operable breast cancer with positive axillary nodes.

Patients and methods: Three hundred fourteen premenopausal patients with ER-positive, node-positive breast cancer were enrolled between July 1979 and July 1989. Patients were stratified according to number of involved nodes and type of primary surgery and randomized to receive either of the following: (1) cyclophosphamide 60 mg/m2/d by mouth for 1 year, methotrexate 15 mg/m2 intravenously (i.v.) weekly for 1 year, fluorouracil (5-FU) 400 mg/m2 i.v. weekly for 1 year, vincristine .625 mg/m2 i.v. weekly for the first 10 weeks, and prednisone weeks 1 to 10 with doses decreasing from 30 mg/m2 to 2.5 mg/m2 (CMFVP); or (2) bilateral ovariectomy followed by CMFVP.

Results: The median follow-up time is 7.7 years and the maximum 13.2 years. Treatment arms are not significantly different with respect to either survival or DFS (one-sided log-rank, P = .55 and .70, respectively). The 7-year survival rate is 71% on the CMFVP arm and 73% on CMFVP plus ovariectomy. No significant differences were observed in node or receptor level subsets.

Conclusion: We conclude that, in this study, the addition of ovariectomy did not improve results over chemotherapy alone in the treatment of premenopausal women with node-positive, ER-positive, operable breast cancer. Our sample size was too small to detect a small improvement. The death hazards ratio of CMFVP/CMFVP plus ovariectomy was 1.22 (95% confidence interval [CI], .79 to 1.89).