Coffee consumption and bladder cancer: a meta-analysis of observational studies

Sci Rep. 2015 Mar 12:5:9051. doi: 10.1038/srep09051.

Abstract

Controversial results of the association between coffee consumption and bladder cancer (BC) risk were reported among epidemiological studies. Therefore, we conducted this meta-analysis to clarify the association. Relevant studies were identified according to the inclusion criteria. Totally, 34 case-control studies and 6 cohort studies were included in our meta-analysis. The overall odds ratio (OR) with 95% confidence interval (CI) between coffee consumption and BC risk was 1.33 (95% CI 1.19 to 1.48). The summary ORs of BC for an increase of 1 cup of coffee per day were 1.05 (95% CI 1.03 to 1.06) for case-control studies and 1.03 (95% CI 0.99 to 1.06) for cohort studies. The overall ORs for male coffee drinkers, female coffee drinkers and coffee drinkers of both gender were 1.31 (95% CI: 1.08 to 1.59), 1.30 (95% CI: 0.87 to 1.96) and 1.35 (95% CI: 1.20 to 1.51). Compared with smokers (OR = 1.24, 95% CI: 0.91 to 1.70), non-smokers had a higher risk (OR = 1.72, 95% CI: 1.25 to 2.35) for BC. Results of this meta-analysis suggested that there was an increased risk between coffee consumption and BC. Male coffee drinkers and non-smoking coffee drinkers were more likely to develop BC.

Publication types

  • Meta-Analysis
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Case-Control Studies
  • Coffee / adverse effects*
  • Cohort Studies
  • Female
  • Humans
  • Male
  • Odds Ratio
  • Publication Bias
  • Risk
  • Sex Factors
  • Urinary Bladder Neoplasms / epidemiology*
  • Urinary Bladder Neoplasms / etiology*

Substances

  • Coffee