Department of Internal Medicine, Division of Cancer Prevention and Control, The Ohio State University College of Medicine, Columbus, OH, USA.
J Natl Cancer Inst. 2013 Aug 7;105(15):1132-41. doi: 10.1093/jnci/djt174. Epub 2013 Jul 10.
Studies of dietary ω-3 fatty acid intake and prostate cancer risk are inconsistent; however, recent large prospective studies have found increased risk of prostate cancer among men with high blood concentrations of long-chain ω-3 polyunsaturated fatty acids ([LCω-3PUFA] 20:5ω3; 22:5ω3; 22:6ω3]. This case-cohort study examines associations between plasma phospholipid fatty acids and prostate cancer risk among participants in the Selenium and Vitamin E Cancer Prevention Trial.
Case subjects were 834 men diagnosed with prostate cancer, of which 156 had high-grade cancer. The subcohort consisted of 1393 men selected randomly at baseline and from within strata frequency matched to case subjects on age and race. Proportional hazards models estimated hazard ratios (HR) and 95% confidence intervals (CI) for associations between fatty acids and prostate cancer risk overall and by grade. All statistical tests were two-sided.
Compared with men in the lowest quartiles of LCω-3PUFA, men in the highest quartile had increased risks for low-grade (HR = 1.44, 95% CI = 1.08 to 1.93), high-grade (HR = 1.71, 95% CI = 1.00 to 2.94), and total prostate cancer (HR = 1.43, 95% CI = 1.09 to 1.88). Associations were similar for individual long-chain ω-3 fatty acids. Higher linoleic acid (ω-6) was associated with reduced risks of low-grade (HR = 0.75, 95% CI = 0.56 to 0.99) and total prostate cancer (HR = 0.77, 95% CI = 0.59 to 1.01); however, there was no dose response.
This study confirms previous reports of increased prostate cancer risk among men with high blood concentrations of LCω-3PUFA. The consistency of these findings suggests that these fatty acids are involved in prostate tumorigenesis. Recommendations to increase LCω-3PUFA intake should consider its potential risks.
关于饮食ω-3 脂肪酸摄入量与前列腺癌风险的研究结果并不一致；然而，最近的大型前瞻性研究发现，血液中长链 ω-3 多不饱和脂肪酸（[LCω-3PUFA]20:5ω3；22:5ω3；22:6ω3）浓度较高的男性患前列腺癌的风险增加。本病例-队列研究检查了在硒和维生素 E 癌症预防试验中参与者的血浆磷脂脂肪酸与前列腺癌风险之间的关联。
病例组为 834 名被诊断患有前列腺癌的男性，其中 156 名患有高级别癌症。子队列由 1393 名男性组成，这些男性在基线时随机选择，并根据年龄和种族与病例组进行分层频率匹配。比例风险模型估计脂肪酸与前列腺癌总体风险和分级风险之间的风险比（HR）和 95%置信区间（CI）。所有统计检验均为双侧检验。
与 LCω-3PUFA 最低四分位的男性相比，LCω-3PUFA 最高四分位的男性患低级别（HR=1.44，95%CI=1.08 至 1.93）、高级别（HR=1.71，95%CI=1.00 至 2.94）和总前列腺癌（HR=1.43，95%CI=1.09 至 1.88）的风险增加。个别长链 ω-3 脂肪酸的相关性也相似。较高的亚油酸（ω-6）与低级别（HR=0.75，95%CI=0.56 至 0.99）和总前列腺癌（HR=0.77，95%CI=0.59 至 1.01）的风险降低相关；然而，不存在剂量反应关系。
本研究证实了先前关于血液中 LCω-3PUFA 浓度较高的男性前列腺癌风险增加的报告。这些发现的一致性表明，这些脂肪酸参与了前列腺肿瘤的发生。增加 LCω-3PUFA 摄入量的建议应考虑其潜在风险。
