99m Tc-rituximab as a tracer for sentinel lymph node biopsy in breast cancer patients: a single-center analysis

Purpose This study aimed to determine the long-term prognosis of breast cancer patients with 99m Tc-rituximab for sentinel lymph node biopsy (SLNB). Methods A total of 2947 patients with negative sentinel lymph nodes (SLNs) omitting axillary lymph node dissection (ALND), treated between June 2005 and December 2013, were retrospectively analyzed. SLNB was performed prior to adjuvant therapy. Results After a median follow-up of 62 months, 22 cases of axillary recurrence (AR) were observed. The 5-year AR rate (ARR) was 0.7% [95% confidence interval (CI) 0.3–1.1%] and the 5-year relapse-free survival (RFS) was 95.2% (95% CI 94.4–96.0%). Multivariate analysis showed that abnormal axillary ultrasound with negative fine-needle aspiration (FNA) [hazard ratio (HR) 3.79, 95% CI 1.55–9.28; P = 0.004], not receiving radiotherapy (HR 4.38, 95% CI 1.47–13.05; P = 0.008), and age ≤ 40 years (HR 2.93, 95% CI 1.19–7.20; P = 0.020) were independent risk factors for AR. Conclusions ARR of SLNB-negative patients with 99m Tc-rituximab is low. Abnormal axillary ultrasound with negative FNA, not receiving radiotherapy, and age ≤ 40 years were prognostic factors for higher ARRs.