Analysis of risk factors for axillary metastasis in sentinel lymph node positive breast cancer patients

Objective: To investigate the risk factors for axillary metastasis in patients with sentinel lymph nodes (SLN) positive breast cancer (BC). Methods: Pathological data of 192 BC patients with positive results of sentinel lymph node biopsy who underwent axillary lymph node dissection (ALND) were analyzed. The predictive model of the Memorial Sloan-Kettering Cancer Center (MSKCC) was used to predict the risk of axillary non-SLN metastasis in patients, and the accuracy of the model was evaluated by the receiver operating characteristic (ROC) curves. Results: The results showed no statistical differences in age, tumor type, estrogen receptor expression, tissue differentiation, and the number of negative SLNs (all P > 0.05), but statistical differences in tumor size, tumor number, the number of positive SLNs, and SLN metastasis rates were significant (all P < 0.05). Multivariate logistic analysis showed that the tumor size, the number of tumors, and positive SLN rates were independent risk factors for non-SLN metastasis. The area under the ROC curve of the MSKCC model was 0.771. Conclusion: Tumor size, the number of tumors, and positive SLN rates are independent risk factors for axillary non-SLN metastasis in SLN-positive patients. If the SLN is positive associated with the presence of these clinical symptoms, ALND is therefore advised. The MSKCC model has a high predictive accuracy for breast cancer patients with non-SLN metastasis.