Division of Epidemiology and Community Health and Masonic Cancer Center, University of Minnesota, Minneapolis, MN 55454, USA.
Gut. 2011 Jan;60(1):66-72. doi: 10.1136/gut.2010.208074. Epub 2010 Nov 10.
Folate has been implicated as a potential aetiological factor for colorectal cancer. Previous research has not adequately exploited concentrations of folate in normal colonic mucosal biopsies to examine the issue.
Logistic regression models were used to estimate ORs and 95% CIs of adenoma according to the tissue concentration of folate using asymptomatic average-risk women (40-70 years) in a colorectal cancer screening study. Of the 1593 eligible women who were offered enrolment, 1483 (93%) participated. Colonoscopy was complete to the caecum in 98.7% (1463/1483) of the subjects, and normal colonic tissue biopsies were obtained from 813 (56%) of these, of whom 170 had at least one adenoma.
A marginal reduction in risk for proximal adenomas (OR 0.56, 95% CI 0.29 to 1.09) but not distal adenomas (OR 1.01, 95% CI 0.43 to 2.37) was observed among women in the highest quintile of tissue folate concentration. A significant reduction in risk for advanced adenoma was observed for women in the highest quintile of tissue folate concentration (OR 0.24, 95% CI 0.06 to 0.93). Defining the outcome as proximal adenomatous and/or hyperplastic polyps, statistically significant inverse associations with tissue concentrations of folate were also observed (OR 0.54, 95% CI 0.31 to 0.95 for quintile 5 vs quintile 1).
These findings are consistent with the hypothesis that folate status of colonic mucosa is an exposure that is aetiologically important in determining the risk of particular molecular subtypes of colorectal cancer.
叶酸已被认为是结直肠癌的潜在病因之一。之前的研究并没有充分利用正常结直肠黏膜活检中的叶酸浓度来研究这个问题。
使用结直肠癌筛查研究中无症状平均风险女性（40-70 岁）的组织叶酸浓度，使用逻辑回归模型估计腺瘤的 OR 和 95%CI。在 1593 名符合条件的女性中，有 1483 名（93%）参与了研究。98.7%（1463/1483）的受试者结肠镜检查完成至盲肠，其中 813 名（56%）获得了正常结直肠组织活检，其中 170 名至少有一个腺瘤。
在组织叶酸浓度最高五分位的女性中，近端腺瘤（OR 0.56，95%CI 0.29-1.09）的风险略有降低，但远端腺瘤（OR 1.01，95%CI 0.43-2.37）的风险没有降低。在组织叶酸浓度最高五分位的女性中，高级别腺瘤的风险显著降低（OR 0.24，95%CI 0.06-0.93）。当将结局定义为近端腺瘤性和/或增生性息肉时，也观察到与组织叶酸浓度呈显著负相关（五分位 5 与五分位 1 相比，OR 0.54，95%CI 0.31-0.95）。
这些发现与以下假设一致，即结直肠黏膜的叶酸状态是决定特定结直肠癌分子亚型风险的一个重要病因暴露因素。
