Impact of Sentinel Lymph Node Biopsy on Treatment Decision and Survival in Patients Aged 70 Years with Breast Cancer: A Retrospective Study

Background: Whether sentinel lymph node biopsy should be performed in patients >= 70 years old with early-stage invasive breast cancer is controversial. We examined the effect of sentinel lymph node biopsy on the treatment and outcomes in this population. Materials and Methods: In this retrospective study, patients aged >= 70 years who were treated for invasive breast cancer with sentinel lymph node biopsy followed by mastectomy or lumpectomy between 2010 and 2019 were identified from our database. Patients were compared according to sentinel lymph node status. Outcomes were analyzed using the Kaplan-Meier method and Cox multivariate analysis. Results: Of the 376 patients enrolled in this study, 311 (82.7%) were sentinel lymph node-negative and 65 (17.3%) were sentinel lymph node-positive. The median follow-up duration for all patients was 70 months. Systemic treatment and radiation were similar between sentinel lymph node-negative and -positive groups. Disease-free survival, distant disease-free survival, breast cancer-specific survival, overall survival were not significantly different between groups (88.2% vs 87.6%, 96.7% vs 94.8%, 96.2% vs 93.6%, and 93.5% vs 90.0%, respectively). Sentinel lymph node status, tumor size, chemotherapy, endocrine therapy, and adjuvant radiation were included in Cox multivariate analysis. None of the variables were found to significantly affect disease-free survival, distant disease-free survival, breast cancer-specific survival, and overall survival. Conclusions: Our analysis indicated that sentinel lymph node status may not affect systemic treatment decisions or survival in patients aged >= 70 years with breast cancer.