SSO, ASTRO Issue Guidelines for Margin Removal in Breast Surgery

Removing a wider margin around the edge of a cancerous breast tumor can potentially reduce additional breast surgeries and improve patient outcomes, according to guidelines issued by the Society of Surgical Oncology (SSO) and the American Society for Radiation Oncology (ASTRO).

In a joint statement from SSO and ASTRO, the organizations note that about “25% of breast cancer patients are asked to return to the operating room following a lumpectomy to obtain a wider margin by removing more normal tissue around the cancer, known as re-excision of the breast.”

A debate in the medical community revolves around this second surgery—namely, if it is beneficial in reducing the risk of local recurrence, and how much tissue should be removed.

To investigate, the Susan G. Komen Foundation provided funding to Monica Morrow, MD, of the SSO to convene leaders in surgical oncology, radiation oncology, medical oncology, pathology, and patient advocacy to conduct a meta-analysis of margin width and ipsilateral breast tumor recurrence (IBTR) based on a systemic review of 33 studies, including 28,162 patients as the primary evidence-base for consensus. The panel was asked to determine the optimal margin width in breast-conserving surgery for stage I and II invasive breast cancer. The results of randomized clinical trials, reproducibility of margin assessment, and current patterns of multimodality care were also considered.

The panel concluded that “positive margins (ink on invasive carcinoma or ductal carcinoma in situ) are associated with a two-fold increase in the risk of IBTR compared to negative margins. This increased risk is not mitigated by favorable biology, endocrine therapy or a radiation boost. More widely clear margins than no ink on tumor do not significantly decrease the rate of IBTR. There is no evidence that more widely clear margins reduce IBTR for young patients, unfavorable biology, lobular cancers, or cancers with an extensive intraductal component.”

The panel said that “evidence does not support the routine removal of larger amounts of healthy breast tissue beyond the edge of the tumor for any women, including those with aggressive triple negative breast cancer.” SSO and ASTRO are releasing the guidelines to doctors and oncologists today in hopes of influencing clinical practice.

Read the SSO-ASTRO guidelines on the SSO web site or in Annals of Surgical Oncology.