Reoperation for Margins After Breast Conservation Surgery

Abstract

More than 30 years after demonstration that survival after breast conservation surgery (BCS) and adjuvant radiotherapy is equivalent to survival after mastectomy,1 significant variability in the implementation of BCS remains, particularly in the rates of reoperation for margins. Breast conservation surgery is the most common oncologic operation performed in the United States, with a measurable financial and physical burden caused by repeated excisions. In this issue of JAMA Surgery, the study by Isaacs et al2 reports a mean 90-day reoperation rate of 30.9% from 2003 to 2013 in New York State, with a significant decrease over time from 38.5% to 23.1%. This study shows that almost onethird of the reoperations results in mastectomy. In 2014, Wilke et al3 similarly demonstrated that within the National Cancer Database from 2004 to 2010, the rates of repeated operations after BCS decreased from 25% to 22%. This change is seen within the context of efforts to define adequate margins for BCS.4 The recent Society for Surgical Oncology–American Society for Radiation Oncology (SSOASTRO) consensus guidelines encourage the use of “no ink on tumor” as the current standard in an era of multimodal treatment and evolving understanding of tumor biology along with tumor burden. In fact, this approach to reexcisions echoes the conclusion of Fisher et al5(p1722) in 1986 after review of pathologic findings from the National Surgical Adjuvant Breast Project that “it is most appropriate to regard lines of resection involved only when cancer is transected,” because subjective designations of close margins resulted in second operations with a low yield of residual cancer. Isaacs et al2 report notable intersurgeon variability, with rates of reoperations ranging from 0% to 100%. Studies have shown significant surgeon and institutional variation in clinical practice,6 althoughwithout data regardingmarginwidth, the proportion of this variation attributable to interpretation ofmargin status isunknown. Sourcesof inconsistencymay include surgeon training and volume, radiographic evaluation, andpathologic processing. In addition, subjective elements of surgeon bias may play a role because the authors’ multivariable analysis demonstrated that repeated excisions were significantlymore likely inyoungerpatients and thosewith fewer comorbidities.2 Establishing a rational, evidence-based approach to reexcision as originally proposedbyFisher et al5 and that has been supported by the new SSO-ASTRO guidelines has the potential to provide substantial national cost savings by eliminating reexcisions for closebutnegativemargins.7As theseguidelines for margin status are widely adopted, identification of persistent outliers to these guidelines and assessment of the effect of this practice change on surgical outcomes and value of care for early stage breast cancer should remain important goals.