Alcohol Drinking and Second Primary Cancer Risk in Patients with Upper Aerodigestive Tract Cancers: A Systematic Review and Meta-analysis of Observational Studies

Background: We conducted a systematic review and meta-analysis of existing data from observational studies to assess the strength of the association of alcohol drinking with second primary cancer risk in patients with upper aerodigestive tract (UADT; oral cavity, pharynx, larynx, and esophagus) cancer. Methods: PubMed and Embase were searched up to July 2012 and the reference lists of studies included in the analysis were examined. Random-effects models were used to estimate summary relative risks (RR) and 95% confidence interval (CI). Results: Nineteen studies, 8 cohort and 11 case-control studies, were included. In highest versus lowest meta-analyses, alcohol drinking was associated with significantly increased risk of UADT second primary cancers (RR, 2.97; 95% CI, 1.96-4.50). Significantly increased risks were also observed for UADT and lung combined (RR, 1.90; 95% CI, 1.16-3.11) and all sites (RR, 1.60; 95% CI, 1.22-2.10) second primary cancers. For an increase in the alcohol intake of 10 grams per day, dose-response meta-analysis resulted in a significantly increased RR of 1.09 (95% CI, 1.04-1.14) for UADT second primary cancers. Conclusions: Alcohol drinking in patients with UADT cancer is associated with an increased risk of second primary cancers. Studies conducted in alcohol drinking patients with UADT cancer and evaluating the effect of alcohol cessation on second primary cancer and other outcomes are needed. Impact: Our results emphasize the importance of prevention policies aiming to reduce alcohol drinking. Health-care professionals should encourage alcohol drinking patients with UADT cancer to reduce their consumption and reinforce the surveillance of this at-risk subpopulation.