Objective: Studies evaluating the relationships between coffee, tea and caffeine and ovarian cancer risk have given inconsistent results. We have examined these associations using data from an Australian population-based case-control study.
Methods: Women with epithelial ovarian cancer (EOC) (n = 696) and control women selected from the Electoral Roll (n = 786) provided comprehensive reproductive and lifestyle data and completed a food frequency questionnaire.
Results: Increasing coffee consumption was associated with a decreased risk of invasive EOC ( p trend = 0.009) with an odds ratio (OR) of 0.51 (95% confidence interval (CI) 0.32-0.80) for consumption of >/=4 cups of coffee per day compared to non-drinkers. The association was significant only for serous and endometrioid/clear cell histological subtypes. There was no association with borderline tumours (OR: 1.20, 95% CI: 0.58-2.47). An inverse relationship was also seen between caffeine intake and EOC but tea consumption was not related to EOC (OR: 1.10 95% CI: 0.76-1.61 for >/=4 cups/day versus none).
Conclusions: As tea contributed significantly to caffeine intake in this population we conclude that the association we observed with coffee is not due to caffeine, but to other components within coffee. We suggest future studies consider the type as well as the amount of each beverage consumed.