Abstract 3734: Modified dietary inflammatory index and increased number of colonic aberrant crypt foci

Abstract

Abstract Pro-inflammatory dietary intake has been linked to the development of colorectal cancer (CRC). There is a paucity of data, however, concerning dietary behavior and prevalence of colonic aberrant crypt foci (ACF), an emerging pre-polyp intermediate endpoint thought to be on the pathway to CRC. We assessed this question in a cross-sectional study of 130 patients (mean age = 57.1 yrs) who received colonoscopy at the Colon Cancer Prevention Program at University of Connecticut Health. Typical diet intake was ascertained from the Brief Block Food Frequency Questionnaire, which provided 29 of the 45 food items in the standard Dietary Inflammatory Index (DII). Using advanced chromoendoscopy imaging, ACF were counted by an endoscopist and external reviewer for consensus. In bivariate analyses between ACF quartiles and mean number of daily servings in four food groups, using the Kruskal-Wallis Non-Parametric test, we found evidence of an inverse dose response with reduced intake of grains (3.9, 3.6, 3.1, 2.7, mean servings per ACF quartile, respectively, p = 0.06) and fruit (1.4, 1.2, 1.0, 1.1, mean servings per ACF quartile, respectively, p = 0.06). We observed little variation in vegetable or dairy intake across ACF quartiles. The association between the modified DII (mod-DII) and ACF number (continuous) was assessed using latent variable modeling controlling for continuous variables of age and waist-hip ratio, and, categorical variables of sex, regular aspirin use (≥ 1 pill per week in past 12 months), regular statin use (≥ 1 pill per week in past 12 months), cigarette smoking (ever, never), polyp history (yes, no) and education level. The final model had a good fit (CFI = 0.92, RMSEA<0.05), and showed statistically significant direct associations between ACF number and both increasing mod-DII score (β = 0.18) and ever having smoked cigarettes (β = 0.19). No significant effects were found between ACF number and the remaining variables in the model. In summary, these cross-sectional findings support the growing evidence base about the adverse impact of an overall pro-inflammatory diet in CRC development and potential value of ACF as intermediate endpoints in research. A limitation of this study is lack of information on physical activity, a lifestyle behavior known to reduce CRC risk presumably through anti-inflammatory effects. More research is warranted to explore possible mitigating effects of physical activity, and other factors known to have pro- or anti-inflammatory properties, in the context of inflammation-based classification of diet. Citation Format: Helen Swede, Masteneh Sharafi, Rong Wu, Valerie B. Duffy, Daniel W. Rosenberg, David A. Drew, Thomas Devers, Richard G. Stevens. Modified dietary inflammatory index and increased number of colonic aberrant crypt foci. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 3734. doi:10.1158/1538-7445.AM2015-3734