Impact of smoking on survival in nasopharyngeal carcinoma: A cohort study with 23,325 patients diagnosed from 1990 to 2016

We aimed to compare the survival outcomes of patients with nasopharyngeal carcinoma (NPC) who had different smoking behaviors and were treated with two- or three-dimensional radiotherapy (2D/3DRT) or intensity-modulated radiotherapy (IMRT) with a long-term follow up.From 1990 to 2016, 23,325 patients with NPC were included. The primary endpoint of this study was overall survival (OS). The log-rank test and Cox proportional hazards regression...