Alcohol drinking and laryngeal cancer: overall and dose-risk relation--a systematic review and meta-analysis

Alcohol drinking is a known risk factor for laryngeal cancer. However, little information is available on the risk associated with light alcohol drinking. To address this issue, we conducted a meta-analysis using two methods: (i) random-effects models with reconstruction of alcohol consumption categories and calculation of risk estimates associated with predefined consumption levels using Hamling method and (ii) random-effects meta-regression models. The PubMed database was searched for all case-control or cohort studies published in the English language on the association between alcohol consumption and risk of laryngeal cancer. Forty studies (38 case-control, 2 cohort) reporting on at least three levels of consumption were included. Overall, alcohol drinking versus non-drinking was associated with an approximately 2-fold increase in risk of laryngeal cancer (RR=1.90; 95% CI: 1.59-2.28). While light alcohol drinking (≥1 drink/day) did not show any significant association with risk of laryngeal cancer (12 studies. RR=0.88; 95% CI: 0.71-1.08), moderate drinking (>1 to <4drinks/day) was associated with a 1.5-fold increase in risk (35 studies. RR=1.47; 95% CI: 1.25-1.72) and heavy drinking (⩾4drinks/day) was associated with a 2.5-fold increased risk (33 studies. RR=2.62; 95% CI: 2.13-3.23). Subgroup analyses for studies that adjusted for main potential confounding factors (age, sex, and tobacco use) and several further subgroup analyses showed similar results, which suggest the robustness of the results.