Routine shave margins are not necessary in early stage breast cancer treated with Breast Conserving Surgery

[Interest of systematic shavings to reduce reoperation in breast-conserving surgery of breast cancer]

OBJECTIVE

The INCa and HAS have developed quality and safety indicators for care specific to breast cancer. Among these, in the conservative surgery of this cancer includes the reoperation rate: target˂10%, alert>20%. The main objective of our study was to evaluate whether the practice of systematic recuts still called "shaving" would meet the objectives of the indicators.

METHODS

Observational, retrospective, single-center study over two years in a regional referral center. Two groups of patients were compared: one with "shaving" and one without (no shaving or oriented shaving).

RESULTS

In total, 381 patients were operated on, including 48 (12.6%) with shaving and 333 (87.4%) without. Revision rates for damaged margins were 18.75% (9/48) in the shaving group which met the quality criterias vs. 23.7% (79/333) which did not satisfy them; P=0.4. Furthermore, the rate of discovery of occult sites on recuts was higher in the shaving group: 22.9% (11/48) vs. 9.9% (33/333); P=0.02. In the shaving group, 10.4% (5/48) of the patients were resected again for damaged margins for the initial cancer vs. 18.6% (62/333) in the group without shaving; P=0.23.

CONCLUSION

Our study confirms the interest of performing "shaving" to meet the requirements of the INCa and HAS quality criteria. The absence of systematic cross-sectioning leads to the risk of not recognizing the existence of occult sites. However, the discovery of occult cancers does not significantly reduce the rate of repeat surgery.

Resection of Cavity Shave Margins in Stage 0-III Breast Cancer Patients Undergoing Breast Conserving Surgery: A Prospective Multicenter Randomized Controlled Trial

OBJECTIVE

Single-center studies have demonstrated that resection of cavity shave margins (CSM) halves the rate of positive margins and re-excision in breast cancer patients undergoing partial mastectomy (PM). We sought to determine if these findings were externally generalizable across practice settings.

METHODS

In this multicenter randomized controlled trial occurring in 9 centers across the United States, stage 0-III breast cancer patients undergoing PM were randomly assigned to either have resection of CSM ("shave" group) or not ("no shave" group). Randomization occurred intraoperatively, after the surgeon had completed their standard PM. Primary outcome measures were positive margin and re-excision rates.

RESULTS

Between July 28, 2016 and April 13, 2018, 400 patients were enrolled in this trial. Four patients (2 in each arm) did not meet inclusion criteria after randomization, leaving 396 patients for analysis: 196 in the "shave" group and 200 to the "no shave" group. Median patient age was 65 years (range; 29-94). Groups were well matched at baseline for demographic and clinicopathologic factors. Prior to randomization, positive margin rates were similar in the "shave" and "no shave" groups (76/196 (38.8%) vs. 72/200 (36.0%), respectively, P = 0.604). After randomization, those in the "shave" group were significantly less likely than those in the "no shave" group to have positive margins (19/196 (9.7%) vs. 72/200 (36.0%), P < 0.001), and to require re-excision or mastectomy for margin clearance (17/196 (8.7%) vs. 47/200 (23.5%), P < 0.001).

CONCLUSION

Resection of CSM significantly reduces positive margin and re-excision rates in patients undergoing PM.