Introduction: Epidemiologic data support a positive association between hypercholesterolemia and aggressive prostate cancer, and an inverse association between statin use and aggressive prostate cancer. Saturated fat intake is an important dietary determinant of serum cholesterol levels. However, epidemiologic evidence supporting a role for saturated fat in prostate cancer aggressiveness is mixed. We hypothesized that high saturated fat intake would be associated with increased prostate cancer aggressiveness, and that this association would be modified by statin use.
Methods: Of 1,854 prostate cancer cases in the North Carolina-Louisiana Prostate Cancer Project (PCaP), 321 (17%) were classified as high aggressive based on clinical criteria. Saturated fat intake was adjusted for total fat intake using the residual method, and categorized into tertiles based on the distribution among all research subjects. Using low and intermediate aggressive cases as the reference group, logistic regression was used to examine the association between tertiles of saturated fat intake and prostate cancer aggressiveness, overall and stratified by race and by statin use. In addition to demographic and screening variables, energy-adjusted total fat intake and energy intake were included as covariates in our models. In secondary analysis, we examined associations for total fat, monounsaturated and polyunsaturated fatty acids (MUFA and PUFA, respectively), trans fat, and cholesterol intake.
Results: High saturated fat intake was associated with an elevated odds ratio (OR) for aggressive prostate cancer (ORupper tertile (T3) vs. lower (T1) 1.44; 95% CI 1.06-1.96; p-trend = 0.020). The magnitude of this association was weaker in statin users (ORT3 vs. T1 1.10; 95% CI 0.63-1.91; p-trend = 0.790) compared to men not using statins (ORT3 vs. T1 1.63; 95% CI 1.11-2.37; p-trend = 0.015). There was a suggestion of a positive association between high cholesterol intake and aggressive prostate cancer among all men (ORT3 vs. T1 1.28; 95% CI 0.94-1.75; p-trend = 0.074), and this association was more pronounced in European Americans (ORT3 vs. T1 1.82; 95% CI 1.15-2.88; p-trend = 0.012). Elevated PUFA intake was inversely associated with prostate cancer aggressiveness (ORT3 vs. T1 0.66; 95% CI 0.48-0.90; p-trend = 0.009), with similar effect estimates in both races. There were no associations between trans fat or MUFA and prostate cancer aggressiveness.
Conclusions: Elevated intake of saturated fat was positively associated, while high intake of PUFA was inversely associated, with aggressive prostate cancer. Weaker associations between saturated fat and prostate cancer aggressiveness in statin users suggest that the impact of saturated fat on serum cholesterol levels may be one potential mechanism by which saturated fat impacts prostate cancer aggressiveness.
Citation Format: Emma H. Allott, Lenore Arab, L. Joseph Su, Laura Farnan, Elizabeth T.H. Fontham, James L. Mohler, Jeannette T. Bensen, Susan E. Steck. Saturated fat intake and prostate cancer aggressiveness: Results from the population-based North Carolina-Louisiana prostate cancer project. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 1760.