Abstract PR04: Prostate cancer risk and dietary folate in a multiethnic population: Higher intake increases risk in the California Collaborative Prostate Cancer Study.

Abstract

Background: High intake of dietary folate has been associated with both increased and decreased risk of prostate cancer in some previous epidemiologic studies which included mostly non-Hispanic white men. Timing of high folate intake may determine its impact on lesion development. In studies of colon cancer, for instance, high dietary folate appears protective in prelesion men, whereas high folate consumption in postlesion men accelerates cancer cell proliferation. We investigated the association between dietary folate intake and risk of advanced and localized prostate cancer among African American and White men from the California Collaborative Prostate Cancer Study.

Methods: We examined 737 African American cases (233 advanced stage at diagnosis; 264 localized) and controls (N=240); and 1357 White cases (905 advanced stage; 452 localized) and controls (N=855). Folate intake during the reference year (1 year prior to diagnosis for cases or study selection for controls) was assessed by modified Block Food Frequency Questionnaire and categorized by quartiles. Risk was estimated by fitting conditional logistic regression models adjusted for race/ethnicity, age, and family history of prostate cancer.

Results: Dietary folate intake was linearly related to risk of prostate cancer (p<0.001). Risk increased by 16% for each increase of one quartile. Men in the upper quartile of intake (>632 mg/day) were at 45% increased risk compared to men in the lowest quartile (OR=1.45, 95% CI 1.16-1.81). The associations for advanced (OR=1.41, 95% CI 1.11, 1.81) and localized (OR=1.57, 95% CI 1.17, 2.11) disease were similar. The results were similar for African Americans and Whites.

Conclusions: Recent high folate intake appears to be a risk factor. Men who consume high levels of dietary folate in the postlesion period may be at substantially greater risk for both advanced stage and localized prostate cancer in this multi-ethnic study.

This abstract is also presented as Poster B43.

Citation Format: Glovioell W. Rowland, Esther M. John, Sue A. Ingles. Prostate cancer risk and dietary folate in a multiethnic population: Higher intake increases risk in the California Collaborative Prostate Cancer Study. [abstract]. In: Proceedings of the Fifth AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2012 Oct 27-30; San Diego, CA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2012;21(10 Suppl):Abstract nr PR04.