Local recurrence risk factors in women treated with BCT for early-stage breast cancer.

The article by Revesz and Khan is an excellent summary of the state of our knowledge of margin width in relation to breast cancer recurrence. The importance of preventing local recurrence in women who undergo breast-conserving therapy (BCT) for early-stage breast cancer is underscored by the fact that local recurrence is associated with increased cost, psychosocial distress for the patient, and potentially worse distant disease-free and overall survival.[1] With early breast cancer, adequate local control, and more specifically, adequate surgical margins, are arguably key components of therapy. What constitutes an adequate surgical margin in breast-conserving surgery remains controversial, however. Some have advocated for margins of 10 mm or greater for ductal carcinoma in situ (DCIS), but there are no data from large randomized controlled trials to guide us as to what are safe margins for resection in BCT. In National Surgical Adjuvant Breast and Bowel Project (NSABP) trials, which demonstrated the safety and efficacy of BCT, local recurrence rates were low, and a negative margin was defined as simply no tumor cells at the inked edges of the specimen.[2] Revesz and Khan note that a 2-mm margin is generally considered acceptable for DCIS, although the evidence in favor of a 2-mm margin over a 1-mm margin is primarily derived from retrospective, single-institution studies, not all of which demonstrate an advantage for greater margin width.