Weinstein Stephanie J, Albanes Demetrius, Selhub Jacob, Graubard Barry, Lim Unhee, Taylor Philip R, Virtamo Jarmo, Stolzenberg-Solomon Rachael
Division of Cancer Epidemiology and Genetics, National Cancer Institute, NIH, Nutritional Epidemiology Branch, Suite 320, 6120 Executive Boulevard, Bethesda, MD 20892, USA.
Cancer Epidemiol Biomarkers Prev. 2008 Nov;17(11):3233-40. doi: 10.1158/1055-9965.EPI-08-0459.
Folate intake has been associated with reduced colorectal cancer risk; however, few studies have prospectively examined circulating folate or other related one-carbon biomarkers.
We conducted a nested case-control study within the Alpha-Tocopherol, Beta-Carotene Cancer Prevention Study cohort of 50- to 69-year-old Finnish men to investigate associations between serum folate, vitamin B6, vitamin B12, riboflavin, and homocysteine and risk of colon and rectal cancers. Controls were alive and cancer-free at the time of case diagnosis and matched 1:1 on age and date of baseline fasting serum collection with cases (152 colon and 126 rectal cancers). Multivariate-adjusted odds ratios and 95% confidence intervals were calculated using conditional logistic regression.
Serum vitamin B6 was inversely associated with colon cancer [odds ratio, 0.30 (95% confidence interval, 0.11-0.82) in the highest versus lowest quintile]. An increased risk of colon cancer was suggested for men in the middle quintile of serum folate, but without indication of a dose-response relationship. None of the other serum biomarkers were associated with colon or rectal cancer, and we observed no interactions with alcohol consumption or methionine or protein intake. A priori combinations of the five one-carbon serum biomarkers provided no clear evidence to support a collective influence on colorectal cancer risk.
Our results support the hypothesis that higher vitamin B6 status may play a role in inhibiting colon cancer carcinogenesis; however, folate and other one-carbon related biomarkers were not associated with colon or rectal cancer.
叶酸摄入与降低结直肠癌风险相关；然而，很少有研究前瞻性地检测循环叶酸或其他相关的一碳生物标志物。
我们在α-生育酚、β-胡萝卜素癌症预防研究队列中对50至69岁的芬兰男性进行了一项巢式病例对照研究，以调查血清叶酸、维生素B6、维生素B12、核黄素和同型半胱氨酸与结肠癌和直肠癌风险之间的关联。对照在病例诊断时存活且无癌症，按年龄和基线空腹血清采集日期与病例（152例结肠癌和126例直肠癌）1:1匹配。使用条件逻辑回归计算多变量调整后的比值比和95%置信区间。
血清维生素B6与结肠癌呈负相关[最高五分位数与最低五分位数相比，比值比为0.30（95%置信区间为0.11 - 0.82）]。血清叶酸处于中间五分位数的男性患结肠癌的风险增加，但未显示出剂量反应关系。其他血清生物标志物均与结肠癌或直肠癌无关，并且我们未观察到与饮酒、蛋氨酸或蛋白质摄入之间的相互作用。这五种一碳血清生物标志物的先验组合未提供明确证据支持对结直肠癌风险有共同影响。
我们的结果支持以下假设，即较高的维生素B6水平可能在抑制结肠癌发生中起作用；然而，叶酸和其他一碳相关生物标志物与结肠癌或直肠癌无关。
