Long-Term Outcomes of Sentinel Lymph Node Biopsy for Ductal Carcinoma in Situ.

The use of sentinel lymph node biopsy (SLNB) for ductal carcinoma in situ (DCIS) is controversial. Using population-cohort data, we examined whether SLNB improves long-term outcomes among patients with DCIS who underwent breast-conserving surgery. We identified 12 776 women aged 67-94 years diagnosed during 2001-2013 with DCIS who underwent breast-conserving surgery from the US Surveillance, Epidemiology, and End Results-Medicare dataset, 1992 (15.6%) of whom underwent SLNB (median follow-up: 69 months). Tests of statistical significance are two-sided. Patients with and without SLNB did not differ statistically significantly regarding treated recurrence (3.9% vs 3.7%; P = .62), ipsilateral invasive occurrence (1.4% vs 1.7%, P = .33), or breast cancer mortality (1.0% vs 0.9%, P = .86). With Mahalanobis-matching and competing-risks survival analyses, SLNB was not statistically significantly associated with treated recurrence, ipsilateral invasive occurrence, or breast cancer mortality (P ≥ .27). Our findings do not support the routine performance of SLNB for older patients with DCIS amenable to breast conservation.