Clinical Edge

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Guideline on Margins for Breast-Conserving Surgery

J Clin Oncol; ePub 2016 Aug 15; Morrow, et al

A consensus guideline on margins for breast-conserving surgery with whole-breast irradiation in ductal carcinoma in situ (DCIS) advises using a 2 mm margin as the standard. The guideline was jointly developed by SSO, ASTRO, and ASCO.

A panel looked at 20 studies involving nearly 7,900 individuals to form its recommendations. Among the findings:

• Negative margins halve the risk of ipsilateral breast tumor recurrence (IBTR) compared with positive margins defined as ink on DCIS.

• A 2 mm margin minimizes IBTR risk compared with smaller negative margins.

• More widely clear margins do not significantly decrease IBTR vs 2 mm margins.

• Negative margins less than 2 mm alone are not an indication for mastectomy.

The panel advises considering factors known to impact rates of IBTR when determining the need to re-excise.

Citation:

Morrow M, Van Zee K, Solin L, et al. Society of Surgical Oncology–American Society for Radiation Oncology–American Society of Clinical Oncology consensus guideline on margins for breast-conserving surgery with whole-breast irradiation in ductal carcinoma in situ. [Published online ahead of print August 15. 2016]. J Clin Oncol. doi:10.1200/JCO.2016.68.3573.