There are inconsistent and limited data available to assess the relationship between fat intake and risk of
epithelial ovarian cancer (EOC). We examined the consumption of total fat, fat sources and fat subtypes in
relation to risk of EOC and its major histologic subtypes in the European Prospective Investigation into
Cancer and Nutrition which includes incident invasive (n = 1095) and borderline (n = 96) EOC. Cox
proportional hazards regression was used to estimate hazard ratios (HRs) and 95% confidence intervals
(CIs). In multivariate models, we observed no association with consumption of total fat, animal or plant
fat, saturated fat, cholesterol, monounsaturated fat, or fatty fish and risk of invasive EOC. There was,
however, an increased risk of invasive EOC in the highest category of intake (Quartile 4 vs. Quartile 1) of
polyunsaturated fat (HR = 1.22, 95% CI = 1.02–1.48, Ptrend = 0.02). We did not observe heterogeneity in the
risk associations in comparisons of serous and endometrioid histologic subtypes. This study does not
support an etiological role for total fat intake in relation to EOC risk; however, based on observations of a
positive association between intake of polyunsaturated fat and invasive EOC risk in the current and
previous studies, this fat subtype warrants further investigation to determine its potential role in EOC
development.