Margin status and local recurrence after breast-conserving surgery.

OBJECTIVE

To examine the effect of microscopic tumor at the margins on local recurrence after breast-conserving surgery for invasive carcinoma.

DESIGN

Retrospective review of patients treated with surgical resection followed by radiation therapy.

SETTING

A university-based radiation department and a community-based cancer referral center.

PATIENTS

A consecutive series of 272 women treated between 1982 and 1990.

MAIN OUTCOME MEASURE

Local recurrence according to the histopathologic status of excised margins and the total dose of radiation.

RESULTS

During 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 patients with histologically positive margins (18.2%) than in those with unknown margins (7.1%) or negative margins (3.7%). In the 44 patients with positive margins, the local recurrence rate was 8.3% after radiation 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 invasive carcinoma. Therefore, every effort should be made to achieve negative margins intraoperatively.