Caffeine, type of coffee and risk of ovarian cancer: a dose-response meta-analysis of prospective studies.

Abstract

CONTEXT\nProspective studies on caffeine and different types of coffee intake in relation to the risk of ovarian cancer have shown conflicting results.\n\n\nOBJECTIVE\nThe aim of this study was to perform a dose-response meta-analysis of cohort studies on the association between dietary caffeine intake, different types of coffee consumption and risk of ovarian cancer.\n\n\nDATA SOURCES\nPubMed/Medline, ISI Web of Science, Scopus and EMBASE were searched to identify relevant articles published until October 2018.\n\n\nSTUDY SELECTION\nProspective cohort studies that considered caffeine and different types of coffee as the exposure variable and ovarian cancer as the main outcome variable or as one of the outcome variables were included in this systematic review and meta-analysis. Two authors independently screened 9344 publications. A total of 14 cohort studies were included in the meta-analysis.\n\n\nDATA EXTRACTION\nTwo authors independently extracted the data. Any disagreements were resolved in consultation with the principal investigator.\n\n\nRESULTS\nIn total, 940359 participants, including 4434 subjects with ovarian cancer, aged >20 years were included in this systematic review and meta-analysis. Combining 13 effect sizes, we found no significant association between coffee consumption and risk of ovarian cancer (RR: 1.08; 95% CI: 0.89, 1.33). Also, one additional cup per day of coffee consumption was marginally significantly associated with increased risk of ovarian cancer (RR: 1.02; 95% CI: 0.99, 1.05; P=0.21; I2=0.0%; Pheterogeneity=0.68). No significant association was observed between caffeine intake, caffeinated or decaffeinated coffee consumption and risk of ovarian cancer.\n\n\nCONCLUSIONS\nWe found no significant association between caffeine, different types of coffee and risk of ovarian cancer.