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

Purpose: Mastectomy versus excisional biopsy (lumpectomy) plus radiation for the treatment of stage I and II breast cancer was compared in a prospective randomized study. Patients and Methods: 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. Results: 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. Conclusion: 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.