Mastectomy versus breast-conserving therapy in the treatment of stage I and II carcinoma of the breast: a randomized trial at the National Cancer Institute

Mastectomy versus excisional biopsy (lumpectomy) plus radiation for the treatment of stage I and II breast cancer was compared in a prospective randomized study. From 1979 to 1987, 247 women were randomized and 237 were treated on this study. All patients received a full axillary dissection and all node-positive patients received adjuvant chemotherapy with cyclophosphamide and doxorubicin. Radiation consisted of external-beam therapy to the whole breast with or without supraclavicular nodal irradiation followed by a boost to the tumor bed. The minimum time on the study was 18 months and the median time on the study was 68 months. No differences in overall survival or disease-free survival were observed. Actuarial estimates at 5 years showed that 85% of mastectomy-treated patients were alive compared with 89% of the lumpectomy/radiation patients (P2 = .49; 95% two-sided confidence interval [CI] about this difference, 0% to 9% favoring lumpectomy plus radiation). The probability of failure in the irradiated breast was 12% by 5 years and 20% by 8 years according to actuarial estimates. Of 15 local breast failures, 14 were treated with and 12 were controlled by mastectomy; the ultimate local-regional control was similar in both arms of the trial. These data add further weight to the conclusion that breast conservation using lumpectomy and breast irradiation is equivalent to mastectomy in terms of survival and ultimate local control for stage I and II breast cancer patients.