Forskning

April 4, 2016

Coffee drinking an risk of lung cancer – a meta-analysis

P Boffetta and V Galarraga, 2016,Coffee drinking an risk of lung cancer – a meta-analysis, Caner Epidemiology Biomarkers and Prevention, published online ahead of print.

ABSTRACT

BACKGROUND: Previous epidemiologic results on coffee consumption and lung cancer risk have not been consistent. Furthermore, not all studies have addressed the potential role of tobacco as a confounder in this association. A meta-analysis was conducted to assess the effect of coffee consumption on lung cancer risk independent of tobacco use.

METHODS: A systematic review and a meta-analysis based on random effects models were performed using studies from the PubMed and EMBASE databases, and the references from the retrieved articles. Included were 8 prospective cohorts and 13 case-control studies, which provided data for 19,892 cases and 623,645 non-cases, timeframe 1986-2015.

RESULTS: The meta-relative risk for coffee drinking, not controlling for tobacco smoking, was 1.09 (95%CI 1.00-1.19), reference group was never drinkers. There was significant heterogeneity among the study results (Q= 84.39, I² = 75.1%, heterog. p- value < .001). Among non-smokers, coffee was not associated with lung cancer risk (RR= 0.92, 95%CI 0.75-1.10), reference group was never drinkers. The meta-RR for 1 cup/day increase, unadjusted for smoking, was 1.04 (95%CI 1.03-1.05); the corresponding RR for non-smokers was 0.95 (95%CI 0.83-1.09).

CONCLUSIONS: The pooled estimates indicated that when the potential confounding effect from smoking is controlled for, coffee drinking does not appear to be a lung cancer risk factor. Further pooled analyses, with larger non-smokers population size, are encouraged to confirm these results.

IMPACT: This study illustrates that the association between coffee consumption and lung cancer can be confounded by tobacco smoking.