Coffee and caffeine intake and risk of ovarian cancer: a systematic review and meta-analysis

Abstract

BACKGROUND: Results from earlier publications on the association of coffee and caffeine and risk of ovarian cancer are inconsistent. OBJECTIVE: To evaluate the link between coffee, caffeine, caffeinated coffee, and decaffeinated coffee consumption and risk of ovarian cancer. METHODS: We searched PubMed/Medline, ISI Web of Science, Scopus, and Google Scholar to identify relevant publications up to April 2018. All case-control studies that considered coffee, caffeine, caffeinated coffee, or decaffeinated coffee as the exposure variables and ovarian cancer as the main outcome variable or as one of the outcomes were included in the systematic review. Publications in which odds ratios (ORs) or rate or risk ratios (RRs) and 95 confidence intervals (CIs) were reported, were included in the meta-analysis. RESULTS: A total of 22 case-control studies were included in the systematic review, and 20 studies in the meta-analysis. Overall, 40 140 participants, including 8568 patients with ovarian cancer, aged >/= 17 years were included. Combining 21 effect sizes from 18 studies, no significant association was observed between total coffee intake and risk of ovarian cancer (OR=1.09; 95 CI 0.94 to 1.26). There was no significant association between total caffeine intake and ovarian cancer risk (OR=0.89; 95 CI 0.55 to 1.45). In addition, caffeinated coffee intake was not significantly associated with ovarian cancer (OR=1.05; 95 CI 0.87 to 1.28). However, combining effect sizes from five studies, we found an inverse significant association between decaffeinated coffee intake and risk of ovarian cancer (OR=0.72; 95 CI 0.58 to 0.90). CONCLUSIONS: Our findings indicated an inverse association between decaffeinated coffee consumption and risk of ovarian cancer. No significant association was found between coffee, caffeine or caffeinated coffee intake and risk of ovarian cancer.