Coffee consumption and risk of renal cancer: a meta-analysis of cohort evidence

Purpose There is increasing evidence that coffee consumption is related to reduced risks for some cancers, but the evidence for renal cancer is inconclusive. Therefore, we conducted a meta-analysis to summarize the cohort evidence of this relationship. Methods A literature search was performed in PubMed and Embase through February 2021. Meta-analyses using a random effects model were conducted for reported relative risk estimates (RRs) relating coffee intake and renal cancer incidence or mortality. We also performed a two-stage random effects exposure-response meta-analysis. Between-study heterogeneity was assessed. Results In a meta-analysis of the ten identified cohort studies, we found a summary RR of 0.88 [95% confidence interval (CI) 0.78-0.99] relating the highest vs. the lowest category of coffee intake and renal cancer, with no significant between-study heterogeneity observed (I-2 = 35%, p = 0.13). This inverse association remained among studies of incident cancers (RR 0.85, 95% CI 0.76-0.96) and studies adjusting for smoking and body mass index (RR 0.87, 95% CI 0.77-0.99). Conclusions Our findings from this meta-analysis of the published cohort evidence are suggestive of an inverse association between coffee consumption and renal cancer risk.