The Society of Surgical Oncology and the American Society for Radiation Oncology have announced new surgical guidelines indicating that although negative margins (no ink on tumor) reduce the risk of local recurrence, wider margin widths do not significantly lower this risk—and the routine practice of removing larger amounts of healthy breast tissue beyond the edge of the tumor is not indicated for any women, including those with aggressive triple negative breast cancer.
The new guidelines, published in the Annals of Surgical Oncology, could significantly reduce unnecessary breast surgeries, improve outcomes, and help women make better decisions about surgery.
There has long been controversy regarding the optimal margin width in breast-conserving surgery for invasive breast cancer. Approximately 25 percent of breast cancer patients return to the operating room after breast-conserving surgery so that surgeons can obtain a wider margin by removing more normal tissue around the cancer—a procedure known as re-excision of the breast. Thus far, there has been little data to determine whether re-excision is beneficial in reducing the risk of local recurrence.
A panel of experts convened in 2013 to determine the optimal margin width in breast-conserving surgery for stage I and II invasive breast cancer. The panel performed a meta-analysis of margin width and local recurrence from a systematic review of 33 studies that included a total of 28,162 patients.
The researchers found that positive margins (ink on invasive carcinoma or ductal carcinoma in situ) are associated with a two-fold increase in the risk of local recurrence compared to negative margins. Negative margins (no ink on tumor) minimize the risk of local recurrence; however, wider margin widths do not significantly lower this risk. Therefore, the routine practice to obtain wider negative margin widths than no ink on tumor is not indicated.
The panel recommends that surgeons use “no ink on tumor” as the standard for an adequate margin. This standard is associated with low rates of local recurrence—and could also reduce re-excision rates, improve outcomes, and reduce healthcare costs.
Moran MS, Schnitt SJ, Giuliano AE, et al: Society of Surgical Oncology–American Society for Radiation Oncology Consensus Guideline on Margins for Breast-Conserving Surgery With Whole-Breast Irradiation in Stages I and II Invasive Breast Cancer. Annals of Surgical Oncology. 2014; 21(3): 704-716.