Alcohol is widely consumed and is known as a major risk factor for several types of cancers. Yet, it is unclear whether alcohol consumption is associated with the risk of prostate cancer (PCa) or not. We conducted linear and non-linear dose-response meta-analyses of cohort studies on alcohol consumption and PCa risk by types of alcohol (total, wine, beer, and liquor) and PCa (non-aggressive and aggressive). Pubmed and Embase were searched through April 2020 to identify relevant studies.
Summary relative risk (RR) and 95% confidence interval (CI) were estimated using a random-effects model. For non-aggressive PCa, by alcohol type, the risk increased linearly with liquor (RR per 14 g/day intake (alcohol content in standard drink) being 1.04 (95% CI = 1.02-1.06, I(2) = 0%, three studies) and non-linearly with beer (Pnon-linearity = 0.045, four studies), with increased risk observed in the lower range (RR = 1.03, 95% CI = 1.01-1.05; 14 g/day), with 1.05 (95% CI = 1.01-1.08) at 28 g/day. Wine was not significantly associated with the risk of non-aggressive PCa. For aggressive PCa, a non-linear relationship of diverse shapes was indicated for all types of alcohol in the sensitivity analysis.
Compared to non-drinking, a significant positive association was more apparent at lower dose for liquor (RR = 1.12, 95% CI = 1.04-1.20 at 14 g/day; RR = 1.16, 95% CI = 1.03-1.31 at 28 g/day; Pnon-linearity = 0.005, three studies) but at higher doses for wine (RR = 1.02, 95% CI = 0.90-1.16 at 28 g/day, RR = 1.35, 95% CI = 1.08-1.67 at 56 g/day; Pnon-linearity = 0.01, four studies). In contrast, decreased risks were indicated at lower doses of beer (RR = 0.85, 95% CI = 0.79-0.92 at 14 g/day; RR = 0.79, 95% CI = 0.70-0.90 at 28 g/day, Pnon-linearity < 0.001, four studies).
Total alcohol consumption was not associated with both types of PCa. In this study, we found heterogeneous associations between alcohol intake and PCa by types of alcohol and PCa.
In 2016, alcohol consumption was one of the leading risk factors for cancer development and cancer death globally, causing an estimated 376 200 cancer deaths, representing 4.2% of all cancer deaths, and 10.3 million cancer disability-adjusted life years lost, representing 4.2% of all cancer disability-adjusted life years lost.
The impact of alcohol consumption on cancer in 2016 varied by age group; the proportion of cancer deaths attributable to alcohol consumption ranged from 13.9% of cancer deaths among people aged 30-34 years to 2.7% of cancer deaths among people aged 80-84 years.
The burden of cancers caused by alcohol consumption might be decreased through (i) individual-level and societal-level interventions that reduce alcohol consumption, and (ii) measures that target those risk factors that interact with alcohol consumption to increase the risk of cancer or that directly affect the risk of alcohol-related cancers.