[Development and validation of a multivariate risk model for distant metastasis of advanced nasopharyngeal carcinoma]

To develop a model based on the clinical variables for evaluating the risk of distant metastasis in patients with advanced nasopharyngeal carcinoma (NPC).

From September,2007 to June,2015,a total of 238 consecutive patients with biopsy-proven NPC in stage Ⅲ-Ⅳ(M0) based on the AJCC TNM staging manual were enrolled in this study,including 106 male and 34 female patients with a median age of 45 years (range 18-68 years).In this cohort,126 patients received concurrent chemoradiotherapy,and 24 received chemotherapy and radiotherapy,and 40 had induction chemotherapy.We used the least absolute shrinkage and selection operator (LASSO) method to select the most significant features for establishing the model for assessing the risks of distant metastasis.

Among the 18 clinical variables tested,5 were significantly associated with distant metastasis in advanced NPC,including plasma Epstein-Barr virus (EBV) DNA,neutrophil/lymphocytes (NLR),VCA-IgA,concurrent chemoradiotherapy,and induction chemotherapy.Based on these 5 clinical variables,we established the following model:risk score=1.73×EBV DNA+0.54×NLR+0.38×VCA-IgA-0.95×concurrent chemoradiotherapy-2.37×induction chemotherapy+0.51.The cutoff point of this model was-0.62,which classified the patients into high-risk and low-risk groups for distant metastasis.This model showed a good performance in predicting distant metastasis in patients with advanced NPC (P<0.01).

The model we established herein can be used for evaluating the risks of distant metastasis in patients with advanced NPC and provides assistance in the clinical decision-making on individualized treatment strategy.