Local recurrence after partial mastectomy: Relation to initial surgical margins

BackgroundLocal recurrence (LR) after partial mastectomy (PM) has been associated with inadequate surgical margins. We assessed LR association with initial margins after PM in patients receiving postoperative radiation therapy (RT).MethodsInitial margins, re-excision status, and ipsilateral LR were identified for all patients having initial PM from 2003 to 2008.ResultsSeven hundred twelve patients underwent PM as their final procedure, and 598 (84.0%) had adjuvant RT. Initial margins were positive or <1-mm margins in 166 patients (27.8%). Re-excision was performed for all positive and 20.2% of patients with margins <1 mm. We observed 10 LRs (1.7%) at the 3.4-year mean follow-up. For patients with initial margins <1 mm, the LR rate was 4.2% (7/167) and just .7% for margins ≥1 mm (P = .006).ConclusionsWe report lower LR rates than traditionally reported. The surgical practice of re-excision to achieve margins of 1 to 5 mm needs closer scrutiny because it may have no impact on LR.