Predicting Factors of Nonsentinel Lymph Node Metastasis in Breast Cancer Patients with Sentinel Lymph Node Metastasis

ABSTRACT

PURPOSE: The purpose of this study was to investigate the predictors of nonsentinel lymph node (NSLN) metastasis in breast cancer and to evaluate the usefulness of the scoring systems and nomograms. METHODS: In this analysis, we reviewed the clinicopathologic features of 70 patients who had undergone sentinel lymph node (SLN) biopsy and axillary lymph node dissection. The clinical features of patients, histologic parameters and hormonal receptor status of primary tumor and histopathologic features of SLN metastasis were noted retrospectively. Furthermore, the receiver operating characteristic (ROC) curve was drawn and the area under the ROC curve (AUC) was calculated to assess the discriminative power of the scoring systems and nomograms. RESULTS: The metastatic tumor size in SLN (P<0.001), extracapsular invasion (P=0.002), percentage of positive SLNs among the removed SLNs (P=0.011), primary tumor size (P=0.038) were associated significantly with NSLN metastasis, statistically, in univariate analysis. Based on multivariate logistic regression, the metastatic tumor size was the only prognostic factor of NSLN metastasis (P=0.012). The AUC of Memorial Sloan-Kettering Cancer Center scoring system was greater than other systems, significantly (P=0.004). CONCLUSION: We have shown in this study that it would be possible to predict NSLN status based on the metastatic tumor size in SLN. Although the significance was not achieved in multivariate analysis, the size of primary tumor, extracapsular invasion of metastasis in SLN, percentage of positive SLNs among the removed SLNs had the potential to be a predictive factor of NSLN metastasis. MSKCC scoring system appears to be more effective and accurate than other scoring systems for selecting patients for whom axillary lymph node dissection can be avoided.