Sentinel Node Biopsy After Neoadjuvant Chemotherapy In Breast Cancer: Real Life Results

Purpose: compare demographic, clinical and treatment characteristics of women undergoing neoadjuvant chemotherapy (NAC) for breast cancer (BC) treatment according to the axillary approach and analyze factors associated with the indication of sentinel lymph node biopsy (SLNB) in a real-life scenario. Methods: retrospective cohort study in women diagnosed with BC with indication for NAC. Demographic, clinical, tumor, surgical and adjuvant treatment variables were obtained.. A univariate logistic regression was performed to evaluate the independent factors associated with SLNB indication and a multiple model was applied for adjustments. Results: A total of 918 patients were included in this study, 161 (17.5%) of whom underwent SLNB, 105 (11.4%) who underwent SLNB followed by AL and 652 (71.0%) who underwent AL only. Concerning the adjusted model, women in stage III were 95% less likely to be submitted to an SLNB (OR = 0.05 95% CI 0.01-0.17; p<0.001) compared to those in stage I. Women who underwent mastectomies exhibited a 90% lower chance of undergoing SLNB than those who underwent conservative surgery (95% CI 0.06-0.17; p <0.001). Considering NAC responses, cases with no response or presenting disease progression exhibited a 55% lower chance of undergoing SLNB compared to those displaying a total response (OR = 0.45 95% CI 0.24-0.82; p = 0.009). Conclusion: SLNB was performed in 29% of the patients following NAC. Patients presenting a more advanced clinical stage of the disease with a worse NAC response and those who underwent mastectomies were less likely to undergo SLNB.