Dietary lipids and endometrial cancer: the current epidemiologic evidence.

Background: Because dietary fat has been postulated to affect obesity and estrogen levels, two important risk factors for endometrial cancer, its association with this disease has received some attention. We summarize here the current evidence for several dietary lipids.
Methods: Searches were conducted to identify peer-reviewed manuscripts up to December 2006. Two cohort studies and nine case-control studies were included in meta-analyses.
Results: Random-effects summary estimates for case-control studies were 1.24 (95% CI: 1.10, 1.41) per 10% kcal from total fat and 1.28 (95% CI: 1.12, 1.47) per 10 g/1,000 kcal of saturated fat. The only cohort study evaluating total fat and saturated fat did not find an association. We estimated a 35% increased risk (95% CI: 0.96, 1.90) per 150 mg/1,000 kcal of cholesterol intake, based on six case-control studies. For animal fat (per 10 g/1,000 kcal) the summary estimates were 0.78 (95% CI: 0.63, 0.96) and 1.34 (95% CI: 1.06, 1.69) for two cohort and four case-control studies, respectively.
Conclusions: Case-control data suggest an increased risk for total, saturated, and animal fat. However, the limited available cohort data do not support these associations. Additional data, particularly from prospective studies, are needed before conclusions can be drawn.