Non-viral environmental risk factors for nasopharyngeal carcinoma: a systematic review.

This review aims to systematically summarize the epidemiological studies on nasopharyngeal carcinoma (NPC) conducted over the past half century, covering descriptive epidemiological studies and reports on non-viral risk factors. Multiple lines of epidemiologic evidence for established risk factors are systematically presented in comprehensive tables. The potential interactions among environmental factors and genetic components, and also the impacts of parallel sequencing technology on the aetiology of NPC are discussed. Finally, we propose a modified model for the pathogenesis of nasopharyngeal carcinoma based on the current knowledge.