Breast cancer sentinel lymph node biopsy efficacy after neoadjuvant chemotherapy as axillary staging predictor.

Abstract

Introduction: Selective sentinel lymph node biopsy (SLNB) in breast cancer is the standard method for axillary staging in patients with clinically negative axilla. Studies indicate avoiding axillary lymphadenectomy in patients with negative SLNB, including those who previously received neoadjuvant chemotherapy (NQT). This study aims to determine the efficacy of SLNB in detecting sentinel lymph nodes after QTN in a reference cancer institute in Ecuador.

Materials and Methods: An observational, analytical, and retrospective study was conducted at Hospital SOLCA Guayaquil from January 2015 to December 2020. Eighty-one clinically negative axillary breast cancer patients who received CTN before surgery were evaluated. The variables are sentinel node biopsy, neoadjuvant chemotherapy, diagnostic accuracy, and axillary staging. An odds ratio of 95% was considered, with P <0.05.

Results: Of 81 operated patients, 52 received SLNB, with sampling detecting sentinel nodes in 92.3% of the cases. The percentage of false negatives is 21.7% after QTN. The remaining 29 patients received axillary lymphadenectomy.

Conclusion: SLNB effectively detects the sentinel node in patients with clinically negative breast and axillary cancer, even after neoadjuvant chemotherapy. However, there is a significant risk of false negatives after CTN, which may lead to the need to perform additional axillary lymphadenectomy for a more accurate assessment of axillary staging.