Distant recurrence and margin involvement in invasive breast cancer

The effect of involved margins after breast cancer surgery on distant recurrence (DR) is unknown. We determined the association between margin width or involvement, DR and cancer deaths. PATIENTS AND METHODS: Greater Manchester (GM) and the National Cancer Registry (NCRAS) cohorts were analysed. Margin status after curative surgery was measured. Cox-proportional hazards investigated factors associated with LR, DR and breast cancer deaths. RESULTS: In GM (2010-2014), 2295 (70.2%) patients had clear margins ( > 2 mm), 302 (9.2%) close (1-2 mm) and 673 (20.6%) involved ( < 1 mm) margins. 2030 patients underwent breast conservation surgery (BCS). After multivariable adjustment in BCS patients, involved margins had an increased hazard of DR (HR 1.73, 95% CI:1.03, 2.88, p = 0.037) and LR (HR 2.16, 95% CI:1.31, 3.58, p = 0.003). NCRAS data from 2010-2013 in 16,420 BCS patients included 3,913 patients (23.9%) with final margins