MARGIN STATUS AND LOCAL RECURRENCE AFTER BREAST-CONSERVING SURGERY

Objective: To examine the effect of microscopic tumor at the margins o n local recurrence after breast-conserving surgery for invasive carcin oma. Design: Retrospective review of patients treated with surgical re section followed by radiation therapy. Setting: A university-based rad iation department and a community-based cancer referral center. Patien ts: A consecutive series of 272 women treated between 1982 and 1990. M ain Outcome Measure: Local recurrence according to the histopathologic status of excised margins and the total dose of radiation. Results: D uring a mean follow-up period of 48 months, the overall rate of local recurrence was 6.3%. Local recurrence was more frequent (P=.0001) in p atients with histologically positive margins (18.2%) than in those wit h unknown margins (7.1%) or negative margins (3.7%). In the 44 patient s with positive margins, the local recurrence rate was 8.3% after radi ation doses of 66 Gy or more compared with 21.9% following lower doses . Conclusions: Microscopic involvement of resection margins increases the risk of local recurrence following breast-conserving surgery for i nvasive carcinoma. Therefore, every effort should be made to achieve n egative margins intraoperatively.