Mo Allen, Wu Rong, Grady James P, Hanley Matthew P, Toro Margaret, Swede Helen, Devers Thomas J, Hartman Terryl J, Rosenberg Daniel W
Center for Molecular Medicine, University of Connecticut Health Center, 263 Farmington Ave., Farmington, CT, 06030-3101, USA.
Colon Cancer Prevention Program, Neag Comprehensive Cancer Center, UConn Health, Farmington, CT, USA.
Cancer Causes Control. 2018 Jul;29(7):667-674. doi: 10.1007/s10552-018-1039-7. Epub 2018 May 30.
Excess dietary fat consumption is strongly associated with the risk of colorectal cancer, but less is known about its role in the earliest stages of carcinogenesis, particularly within the proximal colon. In the following case-control study, we evaluated the relationship between the intake of dietary fats and the frequency of early proximal neoplasia [aberrant crypt foci (ACF) or polyps], detectable by high-definition colonoscopy with contrast dye-spray.
Average-risk screening individuals underwent a high-definition colonoscopy procedure as part of larger ongoing clinical study of precancerous lesions in the proximal colon. Dietary fat intake was assessed using the Block Brief Food Frequency Questionnaire, which estimates average dietary intake based on 70 food items. The diets of individuals with no endoscopically identifiable lesions (n = 36) were compared to those with either ACF or polyps detected in the proximal colon.
In multivariate analysis, high dietary intake of total polyunsaturated fatty acids (PUFAs) and intake of omega-6 and omega-3 fatty acids were positively associated with neoplastic lesions in the proximal colon. When comparing ACF and polyp groups separately, a positive association was observed for both proximal polyps (OR 2.28; CI 1.16-7.09) and ACF (OR 2.86; CI 1.16-7.09) for total PUFA intake. Furthermore, the prevalence of proximal ACF was increased with higher intake of omega-6 (OR 3.54; CI 1.32-9.47) and omega-3 fatty acids (OR 2.29; CI 1.02-5.13), although there was no discernible difference in the omega-6/omega-3 ratio.
These results suggest that dietary PUFAs may be positively associated with risk of early neoplasia in the proximal colon. This study provides further evidence that dietary PUFA composition may play an important role in altering the microenvironment within the human colon.
过量摄入膳食脂肪与结直肠癌风险密切相关，但对于其在致癌作用最早阶段，尤其是近端结肠中的作用，人们了解较少。在以下病例对照研究中，我们评估了膳食脂肪摄入量与早期近端肿瘤形成（异常隐窝灶[ACF]或息肉）发生频率之间的关系，这些可通过高清结肠镜检查及造影剂喷洒检测出来。
作为一项正在进行的关于近端结肠癌前病变的大型临床研究的一部分，平均风险筛查个体接受了高清结肠镜检查。使用Block简易食物频率问卷评估膳食脂肪摄入量，该问卷基于70种食物估算平均膳食摄入量。将内镜检查未发现病变的个体（n = 36）的饮食与近端结肠中检测到ACF或息肉的个体的饮食进行比较。
在多变量分析中，高膳食总多不饱和脂肪酸（PUFA）摄入量以及ω-6和ω-3脂肪酸摄入量与近端结肠肿瘤性病变呈正相关。分别比较ACF组和息肉组时，总PUFA摄入量与近端息肉（比值比[OR] 2.28；置信区间[CI] 1.16 - 7.09）和ACF（OR 2.86；CI 1.16 - 7.09）均呈正相关。此外，尽管ω-6/ω-3比值无明显差异，但随着ω-6（OR 3.54；CI 1.32 - 9.47）和ω-3脂肪酸摄入量增加，近端ACF的患病率升高（OR 2.29；CI 1.02 - 5.13）。
这些结果表明，膳食PUFA可能与近端结肠早期肿瘤形成风险呈正相关。本研究进一步证明，膳食PUFA组成可能在改变人类结肠微环境中起重要作用。
