Abstract

In 1976 we began a randomized trial to evaluate breast conservation by a segmental mastectomy in the treatment of Stage I and II breast tumors ≤4 cm in size. The operation removes only sufficient tissue to ensure that margins of resected specimens are free of tumor. Women were randomly assigned to total mastectomy, segmental mastectomy alone, or segmental mastectomy followed by breast irradiation. All patients had axillary dissections, and patients with positive nodes received chemotherapy. Life-table estimates based on data from 1843 women indicated that treatment by segmental mastectomy, with or without breast irradiation, resulted in disease-free, distant-disease–free, and overall survival at five years that was no worse than that after total breast removal. In fact, disease-free survival after segmental mastectomy plus radiation was better than disease-free survival after total mastectomy (P = 0.04), and overall survival after segmental mastectomy, with or without radiation, was better than overall survival after total mastectomy (P = 0.07, and 0.06, respectively). A total of 92.3 per cent of women treated with radiation remained free of breast tumor at five years, as compared with 72.1 per cent of those receiving no radiation (P<0.001). Among patients with positive nodes 97.9 per cent of women treated with radiation and 63.8 per cent of those receiving no radiation remained tumor-free (P<0.001), although both groups received chemotherapy. We conclude that segmental mastectomy, followed by breast irradiation in all patients and adjuvant chemotherapy in women with positive nodes, is appropriate therapy for Stage I and II breast tumors ≤4 cm, provided that margins of resected specimens are free of tumor. (N Engl J Med 1985; 312:665–73.)