Sentinel Lymph Node Biopsy in Early Breast Cancer Using Methylene Blue Dye Alone: a Safe, Simple, and Cost-Effective Procedure in Resource-Constrained Settings

Sentinel lymph node biopsy (SLNB) is done by different techniques in clinically node-negative patients with early breast cancer. In this study, we aim to estimate the identification rates, positivity rates, cost-effectiveness, and outcomes for patients who underwent sentinel node biopsy using methylene blue dye alone. This was a retrospective review of 172 patients with early breast cancer (cT1-3, N0) who underwent SLNB using methylene blue dye alone between January 2014 and December 2018 including their follow-up details until December 2019. The mean age was 51 ± 10.3 (range: 28 to 76) years. There were 63 (36.6%) patients with cT1 tumor, 108 (62.7%) with cT2, and only 1 patient with cT3 tumor. Breast conservation surgery was performed in 62 (36%) while the remaining 110 (64%) underwent simple mastectomy. Sentinel nodes were successfully identified in 165 (95.9%) with a positivity rate of 23.6%. There was no dye-related adverse reactions intra-operatively. The mean duration of follow-up was 26.68 ± 15.9 months (range: 1-60). Chronic arm pain was present in 7 (4%) while none of the patients had lymphedema or restriction of shoulder joint motion. There were no documented axillary nodal recurrences in this cohort. Eight (4.65%) patients were detected to have systemic metastasis. One patient died of brain metastasis from bilateral breast cancer. The mean disease-free survival was 57 months (95% CI: 55-59). Sentinel lymph node biopsy using methylene dye alone is a safe, simple, and cost-effective alternative to isosulfan blue or radio isotope technique in surgical centers with resource constraints.