Serum Phospholipid Fatty Acids and Prostate Cancer Risk: Results From the Prostate Cancer Prevention Trial

Abstract

Inflammation may be involved in prostate cancer development and progression. This study examined the associations between inflammation-related phospholipid fatty acids and the 7-year-period prevalence of prostate cancer in a nested case-control analysis of participants, aged 55-84 years, in the Prostate Cancer Prevention Trial during 1994-2003. Cases (n = 1,658) were frequency matched to controls (n = 1,803) on age, treatment, and prostate cancer family history. Phospholipid fatty acids were extracted from serum, and concentrations of ω-3, ω-6, and trans-fatty acids (TFAs) were expressed as proportions of the total. Logistic regression models estimated odds ratios and 95% confidence intervals of associations of fatty acids with prostate cancer by grade. No fatty acids were associated with low-grade prostate cancer risk. Docosahexaenoic acid was positively associated with high-grade disease (quartile 4 vs. 1: odds ratio (OR) = 2.50, 95% confidence interval (CI): 1.34, 4.65); TFA 18:1 and TFA 18:2 were linearly and inversely associated with risk of high-grade prostate cancer (quartile 4 vs. 1: TFA 18:1, OR = 0.55, 95% CI: 0.30, 0.98; TFA 18:2, OR = 0.48, 95% CI: 0.27, 0.84). The study findings are contrary to those expected from the pro- and antiinflammatory effects of these fatty acids and suggest a greater complexity of effects of these nutrients with regard to prostate cancer risk.

Scientific Opinion on the extension of use for DHA and EPA-rich algal oil fromSchizochytriumsp. as a Novel Food ingredient

“…No significant associations were found between individual blood levels of EPA or DHA and total prostate cancer risk, risk of advanced prostate cancer, or risk of highgrade prostate cancer. In a further analysis, the authors combined the results obtained for DHA and for EPA individually and found a positive association in this combined analysis of EPA and DHA and risk of high-grade prostate cancer (pooled RR = 1.39, 95 % CI = 1.07-1.80; p = 0.021; I 2 = 17.6 %, p = 0.291), based on one case-control and three nested case-control studies (Crowe et al, 2008;Park et al, 2009;Shannon et al, 2010;Brasky et al, 2011). However, the Panel notes that there is no rationale for combining the results obtained for DHA and for EPA individually in a pooled estimate.…”

“…Considering the individual results of available nested case-control studies which looked at DHA alone and total prostate cancer risk, three reported a positive association (Crowe et al, 2008;Brasky et al, 2011;Brasky et al, 2013), three found no significant association (Harvei et al, 1997;Mannisto et al, 2003;Park et al, 2009) and two found a negative association (Norrish et al, 1999;Chavarro et al, 2007); no significant association was found in the five available case-control studies (Godley et al, 1996;Newcomer et al, 2001;Ukoli et al, 2009;Shannon et al, 2010;Ukoli et al, 2010). With respect to DHA and low-or high-grade prostate cancer risk, one nested case-control study reported a positive association for low-but not high-grade prostate cancer (Brasky et al, 2013), while another nested case-control study reported opposite findings (Brasky et al, 2011); three nestedcase control (Chavarro et al, 2007;Crowe et al, 2008;Park et al, 2009) and one case-control study (Shannon et al, 2010) found no significant association with either low-or high-grade prostate cancer. Overall, the Panel notes that results from studies on an association between blood biomarkers of DHA and EPA and prostate cancer risk are inconsistent, with a majority of nested case-control and casecontrol studies finding null or negative associations.…”

The relevance of serum levels of long chain omega-3 polyunsaturated fatty acids and prostate cancer risk: A Meta-analysis

“…[33][34][35][36][37][38] All studies uniformly compared prostate cancer risk with the groups of involved population with the highest blood level of long chain n-3 PUFA and the reference group (lowest blood level). Most studies analyzed risk of prostate cancer development as part of their studies' outcome.…”

“…28,[35][36][37] Five studies included high-grade tumour (defined as tumour Gleason score ≥7) in their analysis of outcome. 30,[35][36][37][38] The age range of the study population was 40 to 86 years old. Overall, we analyzed 4516 prostate cancer cases and 5728 matching controls.…”

Omega-3 long-chain polyunsaturated fatty acids and aquaculture in perspective

“…Two recent studies have associated n-3 LC-PUFA status with prostate cancer (Brasky et al, 2011(Brasky et al, , 2013. The interpretation of these data has been criticized on a number of grounds including the fact that n-3 LC-PUFA intake was not monitored in these studies and, as n-3 LC-PUFA supplementation is not uncommon in cancer patients (see above), the reason for the observed association between n-3 LC-PUFA and prostate cancer cannot be established.…”