Abstract 843: Coffee consumption and risk of renal cell carcinoma: A meta-analysis of cohort evidence

Background: Coffee consumption has been associated with a reduced risk of some cancers, although for renal cell carcinoma (RCC) the evidence is inconclusive. Several cohort analyses investigating coffee intake and RCC have been conducted, although most have been limited by small case numbers. To summarize the cohort evidence of this relationship, we conducted a meta-analysis. Methods: A literature search was performed in PubMed, Embase and The Cochrane Library for all studies published up to May 2020 using the key words “cancer”, “tumor”, “carcinoma”, “malignant neoplasm”, “renal cell carcinoma”, “kidney cancer”, “renal cancer” “coffee”, “caffeine” and “beverages”. Additionally, the reference lists of all retrieved articles and previous meta-analysis studies were checked to identify additional studies. From our collection of full-text articles (n=7219) we excluded irrelevant topic articles (n=7125), non-English articles (n=2), systematic reviews or editorial letter (n=46), relevant articles not reporting measure of association (n=9), case-control studies (n=27). Following these exclusions, 10 cohort studies remained. Meta-analyses using a random effects model were conducted for relative risks (RRs) contrasting the highest vs lowest level of coffee intake per day. In addition, meta-analyses were conducted for reported sex-specific findings as well as findings restricted to non-smokers. Between-study heterogeneity was assessed using Cochran Q-statistic and quantified by Higgins I2 statistic. Results: In a meta-analysis of the 10 identified studies, we found a summary RR of 0.88 (95% CI 0.78-0.99) relating the highest study category of coffee intake (vs. the lowest category or non-drinkers) and renal cancer risk, with no significant between-study heterogeneity observed (I2=35%, p = 0.13). The summary RR was comparable for men and women (0.89 and 0.85 respectively). A slightly stronger inverse association was observed among non-smokers (RR 0.78, 95% CI 0.59-1.03), although with moderate evidence of study heterogeneity (I2=62%, p = 0.07). Conclusions: In this meta-analysis of cohort evidence, we observed overall evidence suggestive of a weak inverse association between higher coffee consumption and lower renal cancer risk. Citation Format: Jongeun Rhee, Rachel Lim, Mark P. Purdue. Coffee consumption and risk of renal cell carcinoma: A meta-analysis of cohort evidence [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 843.