Delay in surgery is associated with axillary upstaging of clinically node negative breast cancer patients

Background and Objectives: Most breast cancer (BC) patients present with early disease and clinically negative lymph nodes (cN0). Timing of surgery has not been standardized. We hypothesized that surgical delay results in an increased likelihood of nodal metastasis. Methods: Patients diagnosed with cN0 BC undergoing surgery with sentinel lymph node biopsy as initial therapy between 2006 and 2014 were identified in the NCDB and divided into four groups based on time intervals between diagnosis and surgery (<4 weeks, 4–8 weeks, 8–12 weeks, and >12 weeks). Regression analysis evaluated the independent impact of surgical timing on axillary upstaging and survival. Results: Of 355,443 patients with cN0 BC, 39.6% had surgery within 4 weeks and 5.4% more than 12 weeks from diagnosis. After controlling for relevant factors, a month delay in surgery was associated with an increased likelihood of nodal positivity (odds ratio: 1.04; 95% confidence interval [CI]: 1.04–1.05; p <.001) and decreased overall survival (hazard ratio: 1.03; 95% CI: 1.02–1.04; p <.001). When compared to patients who underwent surgery less than 4 weeks from diagnosis, the absolute increase in nodal positivity and relative risks were 5.3% (95% CI: 0.047–0.059) and 1.34 (95% CI: 1.30–1.38), respectively, in the more than 12 weeks group. Conclusions: Delay in BC surgery in cN0 patients was associated with an increased likelihood of axillary upstaging and decreased survival.