Risk Factors Of Non-sentinel Lymph Nodes Metastasis And Validation Of MSKCC Nomogram In A Chinese Breast Cancer Population With Positive Sentinel Lymph Nodes

Objectives:To explore the risk factors influencing the non-sentinel lymph nodes status, and to assess the clinical application value of Memorial Sloan-Kattering Cancer Center (MSKCC) nomogram in predicting NSLN metastases in breast cancer patients with positive sentinel lymph nodes (SLN) in Zhejiang, China.Methods:Retrospective analysis of breast cancer patients who were diagnosed with pathological positive sentinel lymph nodes and received further axillary lymph node dissection (ALND) in the Second Affiliated hospital of Zhejiang University School of Medicine from January 2015 to December 2015. The status of the SLN and NSLN were diagnosed by frozen section during the operation and hematoxylin-eosin staining post operation. MSKCC nomogram was used to calculate each patient’s NSLN metastasis risk score, and the predictive accuracy of the MSKCC nomogram was assessed by calculating the area under the receiver-operating characteristic(ROC) curve (AUC).Results:Among the 315 patients who received SLNB,68 SLN positive patients who received ALND were enrolled in the study. In the univariate analysis, the number of positive SLNs (x2=.613, p=0.020) and SLN+/SLN ratio (x2=7.631, p=0.006) were the influencing factors of NSLN metastases. In the multivariate Logistic regression analysis, SLN+/SLN≥0.5 (OR=1.414 95% CI:0.785-2.548, p=0.033) was the independent influencing factors of NSLN metastases. The AUC of MSKCC nomogram in this population is 0.726(95% CI:0.573-0.880). The false-negative rate of the MSKCC nomogram is 7.1% for the predicted probability cut-off of 14%, the false-negative rate of the MSKCC nomogram is 0 for the predicted probability cut-off of 7%.Conclusion:For breast cancer patients with positive SLN, the number of positive SLNs and SLN+/SLN ratio is related to NSLN metastasis. MSKCC has general accuracy in predicting NSLN status of this population.