title: Quantitative association of tobacco smoking with the risk of nasopharyngeal carcinoma: a comprehensive meta-analysis of studies conducted between 1979 and 2011.
abstract: Over the years, many studies have attempted to establish a link between tobacco smoking and an increased risk of nasopharyngeal carcinoma (NPC), but their results have been inconsistent. To clarify this link, we first conducted a comprehensive meta-analysis to integrate the findings of epidemiologic studies from the last half-century. The methodology used for this study followed the checklist proposed by the Meta-analysis of Observational Studies in Epidemiology (MOOSE) Group. Pooled risk estimates were generated using a random-effects model. Twenty-eight case-control studies and 4 cohort studies involving a total of 10,274 NPC cases and 415,266 comparison subjects were included. A substantial effect of smoking on the risk of NPC was identified in this study. The results showed that ever smokers had a 60% greater risk of developing the disease than never smokers (95% confidence interval: 1.38, 1.87); this was a robust dose-dependent association. More importantly, stronger associations were observed in low-risk populations and among persons with the predominant histological type of differentiated NPC than in high-risk populations and persons with an undifferentiated type; the odds ratios were 1.76 and 2.20, respectively, versus 1.29 and 1.27. In this comprehensive meta-analysis, well-established statistical evidence was provided about the role of tobacco smoking in the etiology of NPC.
authors.affiliation: State Key Laboratory of Oncology in Southern China, Department of Experimental Research, Sun Yat-Sen University Cancer Center, Guangzhou 510060, People’s Republic of China.
authors.forename: Wen-Qiong
authors.initials: WQ
authors.lastname: Xue
authors.forename: Hai-De
authors.initials: HD
authors.lastname: Qin
authors.forename: Hong-Lian
authors.initials: HL
authors.lastname: Ruan
authors.forename: Yin Yao
authors.initials: YY
authors.lastname: Shugart
authors.forename: Wei-Hua
authors.initials: WH
authors.lastname: Jia
mesh_terms: D002277:Carcinoma; D016022:Case-Control Studies; D015984:Causality; D015331:Cohort Studies; D015897:Comorbidity; D016001:Confidence Intervals; D004781:Environmental Exposure / Q000032:analysis; D004784:Environmental Monitoring / Q000706:statistics & numerical data*; D005260:Female; D006801:Humans; D008297:Male; D000077274:Nasopharyngeal Carcinoma; D009303:Nasopharyngeal Neoplasms / Q000453:epidemiology*; D016017:Odds Ratio; D012307:Risk Factors; D012907:Smoking / Q000453:epidemiology*
keywords: case-control studies; cohort studies; meta-analysis; nasopharyngeal carcinoma; odds ratio; tobacco smoking