Coffee, tea, and caffeine consumption and risk of epithelial ovarian cancer and borderline ovarian tumors: Results from a Danish case-control study

Background. Epidemiological studies that have investigated the association between coffee, tea and caffeine consumption and ovarian cancer risk have produced conflicting results. Furthermore, only few studies have examined the role of coffee and tea consumption separately for borderline ovarian tumors. By use of data from a large Danish population-based case-control study, we examined the risk of ovarian tumors associated with coffee, tea, and caffeine consumption with a particular focus on characterizing risks by tumor behavior and histology. Material and methods. From 1995 through 1999, we included 267 women with ovarian cancer, 115 women with borderline ovarian tumors and 911 randomly selected control women. All women completed a beverage frequency questionnaire with detailed information on coffee and tea consumption. Analyses were performed using multiple logistic regression models. Results. Both coffee (OR = 0.90; 95% CI 0.84-0.97 per cup/day) and total caffeine consumption from coffee and tea combined (OR = 0.93; 95% CI 0.88-0.98 per 100 mg/day) decreased the risk of ovarian cancer. These associations were significant only for the serous and "other" subtypes of ovarian cancer. No relation between tea consumption and ovarian cancer risk was observed. The risk estimates for borderline ovarian tumors resembled those observed for ovarian cancer, but did not reach statistical significance. Conclusions. Our results indicate that coffee consumption and total caffeine consumption from coffee and tea combined is associated with a modest decreased risk of ovarian cancer. However, more biological studies are needed to identify bioactive chemical compounds in coffee that potentially could affect ovarian cancer development.