Systematic construction and external validation of an immune-related prognostic model for nasopharyngeal carcinoma

Background We attempted to identify the most reliable immune-related index for predicting nasopharyngeal carcinoma (NPC) prognosis and to reveal its precise and integrated relationship with NPC progression. Method One thousand seven hundred and six patients with newly diagnosed NPC (1320 from the primary cohort and 386 from the validated cohort) from January 2010 to March 2014 were enrolled. Clinical features and 12 immune-related variables were analyzed. Results A high absolute lymphocyte count (ALC; >3.2 x 10(9)/L) correlated with a poor prognosis of patients with NPC. Significant OS differences were discovered between patients with high ALC and no ALC elevation (p < 0.05, in primary cohort), showing similar prognostic risk to patients with advanced NPC (p > 0.05, in validated cohort). ALC improved the predictive performance of the basic tumor-node-metastasis prognostic model (p = 0.025), which was reliably validated in the external independent cohort. Conclusion High ALC is a surrogate marker for improved prognostic risk stratification in NPC.