Effect of T Stages on the Choice of Axillary Evaluation Modality in Breast Cancer Patients With 1-2 Sentinel Lymph Node Metastases

Abstract

Introduction: The survival benefit of axillary lymph node dissection (ALND), sentinel lymph node biopsy (SLNB) combined with radiation, and ALND combined with radiation remains unclear in breast cancer (BC) patients with 1-2 metastatic sentinel lymph nodes (SLNs). This study aims to rigorously evaluate the prognostic impact of these axillary evaluation modalities on BC patients with varying T-stages and to construct a survival prediction nomogram.

Methods: Following screening for inclusion and exclusion criteria, data pertaining to BC patients were extracted from the SEER database. Overall survival (OS) and breast cancer-specific survival (BCSS) were assessed using Kaplan-Meier curves and Cox proportional hazards model among patients with different stages who underwent various axillary evaluation modalities. A nomogram was constructed to predict the probability of OS and BCSS.

Results: A total of 20,283 patients were included, comprising 9626 who underwent breast-conserving surgery (BCS) and 10,657 who underwent mastectomy. In the T₄ stage stratified analysis, both BCS and mastectomy groups exhibited superior OS and BCSS with ALND compared to SLNB combined with radiation. Further, ALND combined with radiation improved OS. However, for T_1-3 stages, patients treated with ALND experienced similar or worse survival compared to those treated with SLNB combined with radiation. The calibration curve and C-index (0.746-0.794) of the nomogram demonstrated the efficacy of the survival prediction model.

Conclusion: In T_1-3 BC patients with 1-2 metastatic SLNs, SLNB combined with radiation is a safe alternative to ALND. Conversely, for T₄ patients, ALND combined with radiation may offer a preferable choice.

Keywords: Axillary lymph node dissection; Axillary radiation; SEER; Sentinel lymph node biopsy; Stratified analysis of T-stage.