Importance of margin status in outcome of breast-conserving surgery for carcinoma.

Overview

BACKGROUND: The importance of margin status in breast-conserving therapy (BCT) for breast cancer remains unclear. We reviewed our experience with BCT to determine the risk of local recurrence as a function of margin status. METHODS: Stages I and II breast cancers treated with BCT between 1985 and 1990 were reviewed. Two hundred eleven patients were classified based on initial margin status: negative (more than 3 mm), close (3 mm or less), positive, or unknown. The incidence of reexcision and residual tumor is reported in each group. Patients with 36 months or more of follow-up (n = 183) were also stratified by final margin to examine rates of local recurrence and distant recurrence. RESULTS: Residual carcinoma was found in 0%, 24%, 44%, and 48% of the negative, close, positive, and unknown initial margin groups, respectively. The local recurrence rate was equivalent by Fisher exact test in patients with negative and close final margins (3%). The negative and close groups were not different by chi-squared analysis in terms of T stage, estrogen receptor status, and nodal status. CONCLUSIONS: Although one fourth of patients with close margins have residual tumor, recurrence rates are similar to those with negative margins. Reexcision of close margins is not necessary in patients who undergo BCT for carcinoma.