Evaluation of the Probability of Non-sentinel Lymph Node Metastasis in Breast Cancer Patients with Sentinel Lymph Node Metastasis using Two Different Methods.

Objective: The aim of this retrospective clinical study was to evaluate the accuracy and feasibility of two different clinical scales, namely the Memorial Sloan-Kettering Cancer Center (MSKCC) nomogram and Tenon's axillary scoring system, which were developed for predicting the non-sentinel lymph node (NSLN) status in our breast cancer patients.

Material And Methods: The medical records of patients who were diagnosed with breast cancer between January 2010 and November 2013 were reviewed. Those who underwent sentinel lymph node biopsy (SLNB) for axillary staging were recruited for the study, and patients who were found to have positive SLNB and thus were subsequently subjected to axillary lymph node dissection (ALND) were also included. Patients who had neoadjuvant therapy, who had clinically positive axilla, and who had stage 4 disease were excluded. Patients were divided into two groups. Group 1 included those who had negative NSLNs, whereas Group 2 included those who had positive NSLNs. The following data were collected: age, tumor size, histopathological characteristics of the tumor, presence of lymphovascular invasion, presence of multifocality, number of negative and positive NSLNs, size of metastases, histopathological method used to define metastases, and receptor status of the tumor. The score of each patient was calculated according to the MSKCC nomogram and Tenon's axillary scoring system. Statistical analysis was conducted to investigate the correlation between the scores and the involvement of NSLNs.

Results: The medical records of patients who were diagnosed with breast cancer and found to have SLNB for axillary staging was reviewed. Finally, 50 patients who had positive SLNB and thus were subsequently subjected to ALND were included in the study. There were 17 and 33 patients in Groups 1 and 2, respectively. Both the MSKCC nomogram and Tenon's axillary scoring system were demonstrated to be significantly accurate in the prediction of the involvement of NSLNs (p<0.05 for each). Among all the parameters, the only one that was found to be correlated with the risk of NSLN involvement was the presence of lymphovascular invasion.

Conclusion: The MSKCC nomogram and Tenon's axillary scoring system both seem to be reliable tools for the assessment of NSLN status in SLNB-positive breast cancer in our breast cancer population. Nevertheless, the omission of ALNB in SLNB-positive breast cancer cannot be yet recommended because of the lack of long-term results of current nomograms and scoring systems.