Quantitative association of tobacco smoking with the risk of nasopharyngeal carcinoma: a comprehensive meta-analysis of studies conducted between 1979 and 2011

Am J Epidemiol. 2013 Aug 1;178(3):325-38. doi: 10.1093/aje/kws479. Epub 2013 Jun 19.


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.

Keywords: case-control studies; cohort studies; meta-analysis; nasopharyngeal carcinoma; odds ratio; tobacco smoking.

Publication types

  • Meta-Analysis
  • Research Support, Non-U.S. Gov't
  • Review

MeSH terms

  • Carcinoma
  • Case-Control Studies
  • Causality
  • Cohort Studies
  • Comorbidity
  • Confidence Intervals
  • Environmental Exposure / analysis
  • Environmental Monitoring / statistics & numerical data*
  • Female
  • Humans
  • Male
  • Nasopharyngeal Carcinoma
  • Nasopharyngeal Neoplasms / epidemiology*
  • Odds Ratio
  • Risk Factors
  • Smoking / epidemiology*