Bottom line: Lowering dietary omega-6 fats while providing enough omega-3 fats prolonged survival and delayed prostrate cancer formation.  J. Clin. Invest. 117(7): 1866-1875 (2007).

Summary:Animals fed a diet high in omega-3 and low in omega-6 fats, providing a  low ratio of 1:1, demonstrated the following benefits (compared to animals on a high omega-6 diet):
 
• delivered omega-3 PUFA to the prostate, 
• delayed tumor formation
• delayed tumor progression
• prolonged survival

Researchers Conclusion: “…the omega-6/omega-3 ratio appears to be a critical factor in the effectiveness of prostate cancer suppression, with a higher proportion of omega-3 being more effective”


Link to FREE Full Text:
Berquin IM, Min Y, Wu R, Wu J, Perry D, Cline JM, Thomas MJ, Thornburg T, Kulik G, Smith A, Edwards IJ, D'Agostino R, Zhang H, Wu H, Kang JX, Chen YQ. Modulation of prostate cancer genetic risk by omega-3 and omega-6 fatty acids.J. Clin. Invest. 117(7): 1866-1875 (2007).doi:10.1172/JCI31494.