Effect Modification by Time Since Blood Draw on the Association Between Circulating Fatty Acids and Prostate Cancer Risk

Glucose, lipids and gamma-glutamyl transferase measured before prostate cancer diagnosis and secondly diagnosed primary tumours: a prospective study in the Swedish AMORIS cohort

Background

Improvements in detection and treatment of prostate cancer (PCa) translate into more men living with PCa, who are therefore potentially at risk of a secondly diagnosed primary tumour (SDPTs). Little is known about potential biochemical mechanisms linking PCa with the occurrence of SDPTs. The current study aims to investigate serum biomarkers of glucose and lipid metabolism and gamma-glutamyl transferase (GGT) measured prior to PCa diagnosis and their association with the occurrence of SDPTS.

Methods

From the Swedish AMORIS cohort, we selected all men diagnosed with PCa between 1996 and 2011, with at least one of the five biomarkers of interest (glucose, fructosamine, triglycerides, total cholesterol (TC), GGT) measured on average 16 years before PCa diagnosis (n = 10,791). Multivariate Cox proportional hazards models were used to determine hazard ratios (HR) for risk of SDPTs (overall and subtypes) by levels of the five biomarkers. Effect modification of treatment was assessed.

Results

811 SDPTS were diagnosed during a median follow-up time of 5 years. Elevated levels of triglycerides (HR: 1.37, 95%CI: 1.17–1.60), TC (HR: 1.22, 95%CI: 1.04–1.42) and GGT (HR: 1.32, 95%CI: 1.02–1.71) were associated with an increased risk of SDPTs. Risk of SDPTs subtypes varied by biomarkers.

Conclusion

Elevated levels of biomarkers of lipid metabolism and GGT measured prior to PCa diagnosis were associated with an increased risk of SDPTs, suggesting a potential common biochemical background for development of PCa and SDPTs.

The Association of Fatty Acid Levels and Gleason Grade among Men Undergoing Radical Prostatectomy

Background

Epidemiological data suggest that omega-6 (ω-6) fatty acids (FAs) may be associated with cancer incidence and/or cancer mortality, whereas ω-3 FAs are potentially protective. We examined the association of the ratio of ω-6 to ω-3 FA (ω-6:ω-3) and individual FA components with pathological results among men with prostate cancer (PCa) undergoing radical prostatectomy.

Methods

Sixty-nine men were included in the study. Components of ω-6 (linoleic acid (LA), arachidonic acid (AA), and dihomo-γ-linolenic acid (DGLA)) and ω-3 (docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA)) were analyzed by liquid chromatography/mass selective detector separation. Logistic regression analysis was performed to determine association of FA with pathological high grade (Gleason ≥4+3) disease.

Results

The were 35 men with low grade disease (Gleason ≤3+4) and 34 men with high grade disease. Men with low grade disease were significantly younger (58y vs 61y, p = 0.012) and had lower D’Amico clinical classification (p = 0.001) compared to men with high grade disease. There was no significant association of ω-6:ω-3 with high grade disease (OR 0.93, p = 0.78), however overall ω-6, ω-3, and individual components of ω-6 and ω-3 FAs except EPA were significantly associated with high grade disease (ω-6: OR 3.37, 95% CI: 1.27,8.98; LA: OR 3.33, 95% CI:1.24,8.94; AA: OR 2.93, 95% CI:1.24,6.94; DGLA: OR 3.21, 95% CI:1.28,8.04; ω-3: OR 3.47, 95% CI:1.22,9.83; DHA: OR 3.13, 95% CI:1.26,7.74). ω-6 and ω-3 FA components were highly correlated (Spearman ρ = 0.77).

Conclusion

Higher levels of individual components of ω-6 and ω-3FAs may be associated with higher-grade PCa.

Impact

Studies into the causative factors/pathways regarding FAs and prostate carcinogenesis may prove a potential association with PCa aggressiveness.