Serum Phospholipid Fatty Acids, Genetic Variation in Myeloperoxidase, and Prostate Cancer Risk in Heavy Smokers: A Gene-Nutrient Interaction in the Carotene and Retinol Efficacy Trial
Menée sur 641 patients atteints d'un cancer de la prostate et sur 1 398 témoins, cet essai évalue l'association entre le niveau sérique des acides gras phospholipidiques, des variations du gène codant pour la myéloperoxydase et le risque de cancer de la prostate chez les gros fumeurs
The authors investigated associations of serum phospholipid n-3 and n-6 polyunsaturated fatty acids (PUFAs) and trans-fatty acids with prostate cancer risk, and whether myeloperoxidase G-463A (rs2333227) modified the associations in the Carotene and Retinol Efficacy Trial (CARET) (Seattle, Washington; Irvine, California; New Haven, Connecticut; San Francisco, California; Baltimore, Maryland; and Portland, Oregon, 1985–2003). Prerandomization sera were assayed for fatty acids among 641 men with incident prostate cancer (368 nonaggressive and 273 aggressive (stage III/IV or Gleason score ≥7)) and 1,398 controls. Overall, dihomo-γ-linolenic (quartiles 4 vs. 1: odds ratio (OR) = 0.66, 95% confidence interval (CI): 0.49, 0.95; Ptrend = 0.024) and docosatetraenoic (OR = 0.69, 95% CI: 0.46, 1.02; Ptrend = 0.011) acids were inversely associated with nonaggressive and aggressive prostate cancer risks, respectively. Among men with MPO GG, the genotype upregulating oxidative stress, quartiles 4 versus 1 eicosapentaenoic plus docosahexaenoic acids were suggestively associated with an increased risk of aggressive prostate cancer (OR = 1.66, 95% CI: 0.95, 2.92; Ptrend = 0.07). However, the association was the inverse among men with MPO GA/AA genotypes (Pinteraction = 0.011). Interactions were also observed for docosapentaenoic acid, total n-3 PUFAs, and arachidonic acid. MPO GA/AA vs. GG was associated with a 2-fold increase in aggressive prostate cancer risk among men with low (quartile 1) n-3 PUFAs. This study adds important evidence linking oxidative stress with prostate carcinogenesis.