Abstract 708: A balanced ratio of omega-6 to omega-3 fatty acids intake and prostate cancer prevention, and the potential for effect modification from organophosphate pesticides
Authors: Sadeghi Homa , Lynch Charles , Beane-Freeman Laura , Field William , Snetselaar Linda , Jones Michael , Torner James 
Published: June 2022

Abstract
Purpose: Although the protective effect of omega-3 fatty acids on some cancers (e.g., breast cancer) has been found, dietary effect of a balanced ratio of omega-6 to omega-3 (N-6/N-3) on prostate cancer (PCa), remains unknown. Given the positive association of terbufos and fonofos with PCa in Agricultural Health Study (AHS), we evaluated the association between N-6/N-3 and PCa, and any potential effect modification by terbufos and fonofos exposure.
Study Design: This case-control study was nested within AHS cohort of farmers with dietary data. Cases with all PCa were identified through the statewide cancer registries. Self-administrated questionnaires assessed diet in 1999-2003 and pesticide in 1993-1997. We summed percentages of energy intake from N-6 (Linoleic acid+arachidonic acid) and N-3 (Eicosapentaenoic acid+docosapentaenoic acid+docosahexaenoic acid+α-linolenic acid) and categorized the N-6/N-3 into quartiles. Multivariate logistic regression was used to calculate adjusted odds ratios (aORs), controlling for age at dietary assessment, race, physical activity, smoking, terbufos, fonofos, diabetes, lycopene, family history of PCa, and the interaction of N-6/N-3 with age, terbufos and fonofos. We also conducted a stratified regression analysis by ever-never exposure to terbufos and fonofos.
Results: The multivariate analysis revealed that the lowest N-6/N-3 quartile was significantly associated with a decreased risk of PCa (aOR=0.61, 95% CI: 0.41-0.9) relative to the top quartile. Comparing two strata of terbufos and fonofos exposure (ever-never), the OR in each N-6/N-3 quartile was slightly smaller within “never” group versus the same quartile in ever-exposure with nonsignificant CI limits.
Conclusion: A lower N-6/N-3 was associated with decreased risk of PCa. No significant interactions between organophosphate pesticides and N-6/N-3 were observed.
Category OR 95% CI Pr&gt;ChiSq Odds Ratio of PCa by Quartiles of N-6/N-3; Multivariate Logistic Regression Model (Cases: 681, Controls: 8,184) N-6/N-3 Ratio Q1 0.61 (0.41-0.9) 0.01 N-6/N-3 Ratio Q2 0.87 (0.63-1.21) 0.41 N-6/N-3 Ratio Q3 0.91 (0.69-1.21) 0.52 N-6/N-3 Ratio Q4 1 N-6/N-3 and Terbufos Interaction (1,193 PCa cases and 14,872 controls) Never Exposure to Terbufos N-6/N-3 Q1 0.69 (0.53-0.9) 0.007 N-6/N-3 Q2 0.87 (0.66-1.14) 0.31 N-6/N-3 Q3 0.84 (0.65-1.08) 0.16 N-6/N-3 Q4 1.02 (0.79-1.33) 0.86 Ever Exposure to Terbufos N-6/N-3 Q1 0.86 (0.67-1.10) 0.24 N-6/N-3 Q2 0.92 (0.7-1.21) 0.55 N-6/N-3 Q3 0.91 (0.72-1.16) 0.44 N-6/N-3 Q4 1 Never Exposure to Fonofos N-6/N-3 Q1 0.73 (0.54-0.98) 0.04 N-6/N-3 Q2 0.94 (0.66-1.33) 0.73 N-6/N-3 Q3 0.86 (0.64-1.15) 0.3 N-6/N-3 Q4 1.18 (0.85-1.64) 0.33 Ever Exposure to Fonofos N-6/N-3 Q1 0.85 (0.64-1.14) 0.27 N-6/N-3 Q2 1.14 (0.81-1.59) 0.47 N-6/N-3 Q3 0.96 (0.72-1.27) 0.75 N-6/N-3 Q4 1 1
Citation Format: Homa Sadeghi, Charles Lynch, Laura Beane-Freeman, William Field, Linda Snetselaar, Michael Jones, James Torner. A balanced ratio of omega-6 to omega-3 fatty acids intake and prostate cancer prevention, and the potential for effect modification from organophosphate pesticides [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 708.