Abstract 1903: Reported behavior of eating anything at anytime and risk of colorectal cancer in women

Background: Colorectal cancer is the 2nd leading cause of cancer deaths in the United States. Although numerous studies have assessed the effect of foods and nutrients on colorectal carcinogenesis, few studies have investigated human eating behavior in relation to this cancer. In 1994, to assess behavior control and attitude toward eating, we asked the participants of the Nurses’ Health Study to respond “yes” or “no” to the question “I eat anything I want, anytime I want.” This question was selected because our pilot study showed that it was the most predictive of the total dietary restraint score from the three factor eating questionnaire, a recognized instrument for quantifying eating behavior. In the present study, we assessed whether the reported behavior of eating anything at anytime influenced risk of colorectal cancer. To further understand the biologic effects of this behavior, we examined the relation between reports of eating anything at anytime and various circulating biomarkers. Methods: We prospectively followed 55,540 women in the Nurses’ Health Study who were aged 48 to 73 years, had no history of cancer, ulcerative colitis, or diabetes, and responded to the item “I eat anything I want, anytime I want” in the 1994 questionnaire. From 1994 to 2006, 552 colorectal cancer cases were documented. Blood samples were collected in 1989-1990 and analyzed for 1,994 women. Cox proportional hazards regression was used to assess the association between reported eating behavior and subsequent risk of colorectal cancer; linear regression was used to examine the association between reported eating behavior and levels of circulating biomarkers. Results: We observed a statistically significant positive association between eating anything at anytime and risk of colorectal cancer. After adjusting for age, smoking, body mass index, physical activity, red and processed meat, and other potential risk factors for colorectal cancer, women who reported eating anything at anytime experienced an increased risk of colorectal cancer (RR=1.28, 95% CI=1.06-1.56) compared with those who did not report this behavior. This positive association was largely unchanged in women who underwent lower endoscopy examinations. In analysis of biomarkers, reported behavior of eating anything at anytime was positively associated with fasting plasma levels of insulin (P=0.04) and C-peptide (P=0.05). Conclusion: The positive association between reported behavior of eating anything at anytime and risk of colorectal cancer provides an insight in understanding the impact of eating habits and related lifestyle choices on the development of colorectal cancer. This observed positive association appears to be independent of known or suspected risk factors for colorectal cancer and may be mediated through insulin resistance and the resulting hyperinsulinemia. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 1903. doi:10.1158/1538-7445.AM2011-1903