Ten-year results of a comparison of conservation with mastectomy in the treatment of stage I and II breast cancer.

Background: Breast-conservation therapy for early-stage breast cancer is now an accepted treatment, but there is still controversy about its comparability with mastectomy. Between 1979 and 1987, the National Cancer Institute conducted a randomized, single-institution trial comparing lumpectomy, axillary dissection, and radiation with mastectomy and axillary dissection for stage I and II breast cancer. We update the results of that trial after a median potential follow-up of 10.1 years.
Methods: Two hundred forty-seven patients with clinical stage I and II breast cancer were randomly assigned to undergo either modified radical mastectomy or lumpectomy, axillary dissection, and radiation therapy. The 237 patients who actually underwent randomization have been followed for a median of 10.1 years. The primary end points were overall survival and disease-free survival.
Results: At 10 years overall survival was 75 percent for the patients assigned to mastectomy and 77 percent for those assigned to lumpectomy plus radiation (P = 0.89). Disease-free survival at 10 years was 69 percent for the patients assigned to mastectomy and 72 percent for those assigned to lumpectomy plus radiation (P = 0.93). The rate of local regional recurrence at 10 years was 10 percent after mastectomy and 5 percent after lumpectomy plus radiation (P = 0.17) after recurrences successfully treated by mastectomy were censored from the analysis.
Conclusions: In the management of stage I and II breast cancer, breast conservation with lumpectomy and radiation offers results at 10 years that are equivalent to those with mastectomy.