Objectives: Recent narrative reviews have concluded that there is no support for an association between alcohol consumption and urinary tract cancer. Many individual studies, however, have reported positive associations, although rarely statistically significant. The purpose of this meta-analysis is to summarize and quantify this relationship with more statistical power and to perform a sensitivity analysis on the study characteristics.
Methods: We included 16 epidemiological studies published up to April 1999 and calculated summary odds ratios (SORs), both upgraded and adjusted for age, sex and smoking by meta-regression analyses. The age- and smoking-adjusted SORs (current alcohol drinking vs. non-drinking) were 1.3 (95% CI 0.9-2.0) for six studies with men and 1.0 (95% CI 0.4-2.6) for four studies with women.
Results: The age-, sex- and smoking-adjusted SOR was 1.2 (95% CI 0.9-1.7) for seven studies with men and women combined.
Conclusion: Even though studies differed in methodology, the results were rather consistent. Subgroup analyses by type or amount of alcohol were not possible due to sparse data. We conclude that the available data suggest a slightly increased risk of urinary tract cancer from alcohol consumption for men. The risk related to alcohol consumption for women and the influence of the amount and type of alcohol remain unclear.