Predictive Factors for Non-sentinel Lymph Node Metastasis of Breast Cancer

Abstract

Objective: The indications for axillary dissection after sentinel lymph node biopsy (SLNB) in breast cancer (BC) is gradually decreasing, even for selected patients with positive SLNB. Increased predictability of Non-sentinel lymph node (Non-SLN) metastasis could prevent unnecessary axillary dissection and even eliminate the need for SLNB. In this study we aimed to investigate the clinical and the pathological factors that affect Non-SLN metastasis. Methods: Early breast cancer patients who underwent SLNB between 2013 and 2018 were retrospectively included in the study. Patients were divided into 3 groups; Group-1 SLNB negative patients, Group-2 SLNB positive but Non-SLN negative patients and Group-3 both SLNB and non-SLN positive patients. Groups were compared in terms of demographic data, tumor size, SLN size, Ki-67 percentages, and hormone receptor status. Results: Seventy-six (36.4%) out of 206 patients had positive SLNB. Non-SLN metastases were detected in 33 (42.7%) patients. Mean tumor size found significantly higher in Group 3 (Group-1, 2 and 3 respectively; 20.5 +/- 9.7mm, 21.9 +/- 9.3mm, 25.1 +/- 9.5mm; p<.01). The mean SLN size was significantly bigger in Group-3 (Group-1, 2 and 3 respectively, 13.1 +/- 5.6mm, 13.9 +/- 8.2mm, 16.8 +/- 6.5mm; p<.01). Rate of patients with Ki-67 index higher than 14% was 84.3% in Group-3, 59.1% in Group-2 and 49.2% in Group-1(p<.01). A statistically significant difference was not detected between the groups in terms of hormone receptor status. Conclusion: Tumor size, SLN size and Ki-67 percentages have importance in predicting the presence of Non-SLN metastasis in BC patients. These factors should also be taken into account for the management of the axillary metastasis and adjuvant treatment for BC.