Sentinel Lymph Node Study and Its Relationship with Molecular Profile in Breast Cancer After Neoadjuvant Therapy

Sentinel Lymph Node Study and Its Relationship with Molecular Profile in Breast Cancer After Neoadjuvant Therapy Aim: Lymphoscintigraphy (LS)/sentinel lymph node (SLN) study is one of the controversial issues in patients with breast cancer who have undergone neoadjuvant therapy (NAT).The aim of our study is to investigate the value of LS/SLN study after NAT and to evaluate its relationship with the molecular profile in breast cancer.Methods: This retrospective study included 59 female patients diagnosed with breast cancer who received NAT.Tumor biopsy pathology results were recorded.Following NAT, LS was performed, and SLN biopsy (SLNB) was conducted intraoperatively using a dual-tracer technique (methylene blue and radionuclide).Axillary lymph node dissection (ALND) was performed in selected cases.Intraoperative frozen results and ALND findings were documented.Logistic regression analysis was performed to identify the factors predicting SLN positivity in the study.Results: Among patients with SLN detected in the SLN study, 15 (28.8%) had positive results on intraoperative frozen pathology.A significant relationship was found between SLNB positivity and human epidermal growth factor receptor-2 (HER2) status (p=0.003).Both univariate and multivariate analyses conducted to identify the factors predicting SLNB positivity; HER2 negativity (p=0.004) was determined to be an independent risk factor for SLNB positivity.HER2 negativity increased the risk of SLNB positivity by a factor of 34.1. Conclusion:In the HER2 negative group, LS/SLN study alone may be insufficient, and ALND should be considered in selected cases.On the other hand, it has been shown that LS/SLN study can avoid unnecessary ALND in patients with HER2 positivity.