Objective: To evaluate the risk factors for non-sentinel lymph node (NSLN) metastasis in patients after neoadjuvant chemotherapy (NCT) so as to develop a new predictive model.
Methods: A total of 512 consecutive patients with metastasis in sentinel lymph node (SLN) on neoadjuvant chemotherapy between August 2005 and March 2013 were recruited to evaluate the factors affecting the involvement of NSLN. Logistic regression analysis was performed to construct a predictive model.
Results: There were 115 (22.4%) patients with metastasis in NSLN after axillary lymph node dissection. Univariate analysis showed that tumor size, number of positive SLN, hormone receptor (HR), micrometastasis and clinical response of primary tumor after NCT were associated with the involvement of NSLN (P < 0.05). Multivariate analysis indicated that tumor size, number of positive SLN, HR, micrometastasis and clinical response of primary tumor after NCT were significant independent predictors for NSLN metastasis. Area under the curve was 0.779.
Conclusion: Tumor size, number of positive SLN, HR, micrometastasis and clinical response of primary tumor after NCT were significant independent predictors for NSLN metastasis in patients after NCT. The new model is to be further validated.