Alcohol Drinking and Bladder Cancer Risk From a Pooled Analysis of Ten Cohort Studies in Japan

J Epidemiol. 2020 Jul 7;30(7):309-313. doi: 10.2188/jea.JE20190014. Epub 2019 Jun 15.


Background: The association of alcohol drinking with bladder cancer risk remains unclear in East Asian populations. Aldehyde dehydrogenase 2 (ALDH2) enzyme oxidizes alcohol-metabolized carcinogenic acetaldehyde into acetate. It is well known that the inactive ALDH2 carriers, specific to East Asian populations, have an increased risk of several cancer types because of increased exposure to acetaldehyde after alcohol consumption. The aim of this study was to examine the association between alcohol drinking and bladder cancer risk using data from ten population-based prospective cohort studies in Japan, where approximately 40% of the population has inactive ALDH2 enzyme.

Methods: We analyzed 340,497 Japanese participants with average follow-up of 13.4 years. The association between alcohol drinking and bladder cancer risk was evaluated using Cox regression models within each study, and random-effects models were used to estimate pooled hazard ratios (HRs) with corresponding 95% confidence intervals (CIs).

Results: During 4,729,071 person-years, 936 men and 325 women were newly diagnosed with bladder cancer. Our results showed no evidence of significant association between alcohol drinking and bladder cancer risk even among men who consumed alcohol of ≥69 g/week, with HR of 1.02 (95% CI, 0.79-1.33). The null result was observed consistently among women.

Conclusions: Our findings do not support an association between alcohol drinking and bladder cancer risk in the Japanese, at least without consideration of the polymorphisms of alcohol-metabolizing enzymes.

Keywords: Japan; alcohol drinking; bladder cancer; cohort study; pooled analysis.

MeSH terms

  • Adult
  • Alcohol Dehydrogenase / genetics*
  • Alcohol Drinking / adverse effects*
  • Alcohol Drinking / epidemiology
  • Aldehyde Dehydrogenase / genetics
  • Aldehyde Dehydrogenase, Mitochondrial / genetics
  • Aldehyde Dehydrogenase, Mitochondrial / metabolism*
  • Asians / genetics
  • Female
  • Humans
  • Japan / epidemiology
  • Male
  • Middle Aged
  • Polymerase Chain Reaction
  • Polymorphism, Genetic
  • Prospective Studies
  • Urinary Bladder Neoplasms / epidemiology
  • Urinary Bladder Neoplasms / etiology*


  • Alcohol Dehydrogenase
  • ALDH2 protein, human
  • Aldehyde Dehydrogenase
  • Aldehyde Dehydrogenase, Mitochondrial