Optimal margin width in breast conservation therapy: A review of the current guidelines and literature

Randomized trials have clearly established breast conservation therapy (BCT) as appropriate treatment for early-stage invasive breast cancer. Current evidence shows that positive margins confer a greater than twofold risk of ipsilateral breast tumor recurrence. Thus, patients who have positive margins after BCT warrant re-excision. With regard to negative margins, however, the optimal negative margin width remains unclear. This article reviews the recent guidelines set forth by the Society of Surgical Oncology and the American Society of Radiation Oncology regarding the margin width in stage I and II invasive breast cancer. We also discuss the controversies related to implementation of these guidelines.