Nutritional Epidemiology Branch, Division of Cancer Epidemiology and Genetics, National Cancer Institute, NIH, Department of Health and Human Services, Bethesda, MD, USA.
Cancer Epidemiol Biomarkers Prev. 2012 Jul;21(7):1222-5. doi: 10.1158/1055-9965.EPI-12-0439. Epub 2012 May 23.
The one previous prospective study of vitamin D status and risk of urinary bladder cancer found that male smokers with low serum 25-hydroxy-vitamin D [25(OH)D] were at a nearly two-fold increased risk. We conducted an analysis of serum 25(OH)D and risk of bladder cancer in the Prostate, Lung, Colorectal, and Ovarian (PLCO) Cancer Screening Study and examined whether serum vitamin D binding protein (DBP) concentration confounded or modified the association.
Three hundred and seventy-five cases of bladder cancer were matched 1:1 with controls based on age (±5 years), race, sex, and date of blood collection (±30 days). Conditional logistic regression was used to estimate ORs and 95% confidence intervals (CI) of bladder cancer by prediagnosis levels of 25(OH)D.
We found no strong or statistically significant association between serum 25(OH)D and bladder cancer risk (Q1 vs. Q4: OR, 0.84; 95% CI, 0.52-1.36; P(trend) = 0.56). Further adjustment for, or stratification by, serum DBP did not alter the findings, nor was there a main effect association between DBP and risk.
In contrast to an earlier report, we observed no association between vitamin D status and risk of bladder cancer; this difference could be due to the inclusion of women and nonsmokers in the current study population or due to the differences in the distribution of vitamin D concentrations between the two study populations.
These findings may contribute to future meta-analyses and help elucidate whether the vitamin D-bladder cancer association varies across populations.
此前仅有一项关于维生素 D 状态与膀胱癌风险的前瞻性研究发现，血清 25-羟维生素 D [25(OH)D] 水平较低的男性吸烟者膀胱癌风险增加近两倍。我们对前列腺癌、肺癌、结直肠癌和卵巢癌筛查研究（Prostate, Lung, Colorectal, and Ovarian Cancer Screening Study，PLCO）中的血清 25(OH)D 与膀胱癌风险进行了分析，并检验了血清维生素 D 结合蛋白（DBP）浓度是否会使这种关联产生混杂或改变这种关联。
根据年龄（±5 岁）、种族、性别和采血日期（±30 天），将 375 例膀胱癌病例与对照组进行 1:1 匹配。采用条件 logistic 回归分析，根据诊断前血清 25(OH)D 水平估计膀胱癌的比值比（OR）和 95%置信区间（CI）。
我们发现血清 25(OH)D 与膀胱癌风险之间无明显或统计学显著的相关性（Q1 与 Q4：OR，0.84；95%CI，0.52-1.36；P（趋势）=0.56）。进一步调整或分层血清 DBP 并未改变这些发现，DBP 与风险之间也没有主要的关联。
与早期的报告相反，我们观察到维生素 D 状态与膀胱癌风险之间没有关联；这种差异可能是由于当前研究人群中纳入了女性和不吸烟者，或者是由于两个研究人群中维生素 D 浓度的分布不同。
这些发现可能有助于未来的荟萃分析，并有助于阐明维生素 D-膀胱癌关联是否在不同人群中存在差异。
