Lumpectomy cavity shaved margins do not impact re-excision rates in breast cancer patients.

BACKGROUND

The benefits of taking shaved cavity margins (SCM) at the time of lumpectomy are unclear. We sought to determine if taking SCM decreases re-excision rates by increasing the total breast tissue volume excised.

METHODS

We undertook a retrospective review of breast cancer patients who underwent lumpectomy from 2004 to 2006. Patients were divided into three groups. Group 1 had lumpectomy alone, group 2 had lumpectomy plus select (1-3) SCM, and group 3 had lumpectomy plus complete (≥4) SCM. Pathologic findings and surgical outcomes were compared between groups.

RESULTS

773 cancers treated by lumpectomy were included in this study; 197 were in group 1, 130 were in group 2, and 446 were in group 3. The mean total volume of breast tissue excised in group 1 (106.6 cm(3)) was significantly larger than the volume excised in groups 2 (79.3 cm(3)) and 3 (76.3 cm(3)). Rates of re-excision and successful breast-conservation therapy (BCT) were not significantly different between groups. Despite a lower total volume of breast tissue excised in groups 2 and 3, there was no significant increase in locoregional recurrence rates (LRR) at median follow-up of 54 months.

CONCLUSIONS

Taking additional SCM during lumpectomy resulted in a significantly lower overall volume of breast tissue excised, with no increase in LRR. Contrary to prior studies, we found that SCM did not decrease re-excision rates or impact the success of BCT. Therefore, the main advantage of taking SCM appears to be that less breast tissue is excised, which could potentially improve cosmetic outcomes.