ASO Author Reflections: The Diminishing Impact of Margin Definitions and Width on Local Recurrence Rates following Breast-Conserving Therapy for Early-Stage Invasive Cancer: A Meta-analysis

Excerpt

The question regarding optimal margin width following breast conserving surgery (BCS) has persisted since the inception of breast conserving therapy. While studies initially utilized a “no tumor on ink” paradigm, evolving data led to larger margin width utilization and significant heterogeneity in how clinicians defined negative margins following BCS. The challenge of defining the optimal margin revolves around concerns of higher rates of local recurrence with narrow margins vs negative cosmetic outcomes, morbidity, and the cost of pursuing wider margins with re-excisions. In 2014, a meta-analysis was performed and subsequently a clinical guideline developed from the American Society for Radiation Oncology (ASTRO) and the Society of Surgical Oncology (SSO), concluding “no tumor on ink” should be the standard negative margin definition following BCS.1,2 However, the meta-analysis demonstrated that patients with “close” margins had a higher risk of local recurrence (OR 1.74). …