School of Social and Community Medicine, University of Bristol, Bristol, United Kingdom.
Int J Cancer. 2012 Sep 1;131(5):1187-96. doi: 10.1002/ijc.27327. Epub 2011 Dec 21.
Epidemiological studies suggest that vitamin D protects against prostate cancer, although evidence is limited and inconsistent. We investigated associations of circulating total 25-hydroxyvitamin D (25(OH)D) with prostate specific antigen-detected prostate cancer in a case-control study nested within the prostate testing for cancer and treatment (ProtecT) trial. Conditional logistic regression was used to estimate odds ratios (ORs) and 95% confidence intervals (CIs) quantifying the association between circulating total 25(OH)D and prostate cancer. In case-only analyses, we used unconditional logistic regression to quantify associations of total 25(OH)D with stage (advanced vs. localized) and Gleason grade (high-grade (≥7) vs. low-grade (<7)). Predetermined categories of total 25(OH)D were defined as: high: ≥30 ng/mL; adequate: 20-<30 ng/mL; insufficient: 12-<20 ng/mL; deficient: <12 ng/mL. Fractional polynomials were used to investigate the existence of any U-shaped relationship. We included 1,447 prostate cancer cases (153 advanced, 469 high-grade) and 1,449 healthy controls. There was evidence that men deficient in vitamin D had a 2-fold increased risk of advanced versus localized cancer (OR for deficient vs. adequate total 25(OH)D=2.33, 95% CI: 1.26, 4.28) and high-grade versus low-grade cancer (OR for deficient vs. adequate total 25(OH)D=1.78, 95% CI: 1.15, 2.77). There was no evidence of a linear association between total 25(OH)D and prostate cancer (p=0.44) or of an increased risk of prostate cancer with high and low vitamin D levels. Our study provides evidence that lower 25(OH)D concentrations were associated with more aggressive cancers (advanced versus localized cancers and high- versus low-Gleason grade), but there was no evidence of an association with overall prostate cancer risk.
流行病学研究表明，维生素 D 可预防前列腺癌，尽管证据有限且不一致。我们在前列腺癌检测和治疗（ProtecT）试验中进行了一项巢式病例对照研究，调查了循环总 25-羟维生素 D（25（OH）D）与前列腺特异性抗原检测到的前列腺癌之间的关联。条件逻辑回归用于估计比值比（OR）和 95％置信区间（CI），以量化循环总 25（OH）D 与前列腺癌之间的关联。在仅病例分析中，我们使用非条件逻辑回归来量化总 25（OH）D 与分期（晚期与局限性）和 Gleason 分级（高级（≥7）与低级（<7））之间的关联。总 25（OH）D 的预定类别定义为：高：≥30ng/mL；充足：20-<30ng/mL；不足：12-<20ng/mL；缺乏：<12ng/mL。分数多项式用于研究是否存在任何 U 形关系。我们纳入了 1447 例前列腺癌病例（153 例晚期，469 例高级）和 1449 例健康对照者。有证据表明，维生素 D 缺乏的男性患晚期前列腺癌的风险增加了 2 倍，而局限性癌症（缺乏与充足的总 25（OH）D 相比，OR=2.33，95％CI：1.26，4.28）和高级与低级癌症（缺乏与充足的总 25（OH）D 相比，OR=1.78，95％CI：1.15，2.77）。总 25（OH）D 与前列腺癌之间没有线性关联（p=0.44），也没有证据表明高维生素 D 水平和低维生素 D 水平会增加前列腺癌的风险。我们的研究提供了证据，表明较低的 25（OH）D 浓度与更具侵袭性的癌症（晚期与局限性癌症以及高级与低级 Gleason 分级）相关，但没有证据表明与总体前列腺癌风险相关。
