Cross-Sectional Study to Compare Sentinel Lymph Node Biopsy vs. Complete Axillary Lymph Node Dissection for the Evaluation of Lymph Node Metastasis in Females With Locally Advanced Breast Carcinoma Post Neoadjuvant Chemotherapy

Background Accurate axillary staging after neoadjuvant chemotherapy (NACT) in locally advanced breast cancer is essential for treatment planning. Sentinel lymph node biopsy (SLNB) offers a less morbid alternative to complete axillary lymph node dissection (CALND), but its diagnostic performance after NACT requires evaluation. Aim To evaluate the diagnostic accuracy, specifically the sensitivity and false-negative rate, of SLNB compared to CALND in identifying residual axillary metastasis among females with locally advanced breast carcinoma who achieve a clinically node-negative (cN0) status following neoadjuvant chemotherapy in a tertiary care setting. Materials and methods This prospective, cross-sectional, hospital-based observational study was conducted over one year at a tertiary care teaching hospital in central India. Forty-five consenting females (≥18 years) with cytologically or histologically proven locally advanced breast cancer, who were clinically node-negative after NACT, underwent intraoperative dye-guided SLNB with lower axillary sampling followed by completion axillary lymph node dissection. Histopathology from SLNB and axillary lymph node dissection (ALND) specimens was compared. Diagnostic indices (sensitivity, specificity, predictive values, and accuracy) were calculated using ALND as the reference standard. Results Among 45 subjects, 64.44% were younger than 50 years, and tumors were more often left-sided (60.0%). Invasive ductal carcinoma (IDC) was the most common histologic type (64.4%), and no residual tumor (NRT) was reported in 24.4% of patients. Mean tumor size was 2.15 ± 1.00 cm. SLNB was positive in 18 cases and negative in 27 cases; remaining axillary nodes were positive in 11 and negative in 34 subjects. SLNB demonstrated a sensitivity of 88.89%, specificity of 72.22%, false-negative rate of 11.11%, false-positive rate of 27.77%, positive predictive value of 44.44%, negative predictive value of 96.30%, and overall accuracy of 75.56%. Conclusion SLNB showed high sensitivity and a very high negative predictive value as compared with CALND for post-NACT axillary evaluation in clinically node-negative locally advanced breast cancer. The present findings support SLNB as a preliminary and hypothesis-generating alternative to CALND in the post-NACT setting for clinically node-negative LABC in resource-limited settings, while emphasizing that careful patient selection and adherence to best-practice technical standards are essential to maintain diagnostic reliability.