Lifestyle factors and risk for colorectal polyps and cancer at index colonoscopy in a FIT-positive screening population

Background: Many countries have adopted the fecal immunochemical test (FIT) as the primary colorectal cancer (CRC) screening tool; however, its accuracy is limited. Epidemiological studies have shown that obesity and type 2 diabetes increase risk for the disease. Objective: The objective of this article is to evaluate the association of colorectal polyps and cancer with comorbidities and lifestyle factors in a population that is part of a FIT-based CRC screening program. Methods: Between 2005 and 2013, we analyzed 3894 FIT + patients who underwent total colonoscopy. The impact of lifestyle factors on polyps and cancer was assessed using individuals with a negative colonoscopy as the control group. A multivariate logistic regression analysis was used to estimate odds ratios (ORs) and 95% confidence intervals (CIs). Results: We collected data from 3894 FIT + patients. Obesity (OR 1.29; 95% CI 1.05-1.60) and smoking (OR 1.45; 95% CI 1.24-1.71) were significantly associated with high-risk adenomas. Smoking and heavy alcohol drinking were both independently associated with high risk of CRC (OR 1.50; 95% CI 1.10-2.04 and OR 2.29; 95% CI 1.15-4.58) and colon cancer alone (OR 1.43; 95% CI 1.01-2.02 and OR 3.09; 95% CI 1.53-6.23). Positivity to first round of FIT was associated with high-risk adenomas (OR 1.47; CI 95% 1.26-1.71) and CRC (OR 1.74; 95% CI 1.29-2.36). No associations were found for diabetes. Conclusion: In our FIT + population, lifestyle factors are significantly associated with the risk of carrying high-risk adenomas and CRC. In the future, studies could be aimed at finding better screening strategies through the development of clinical algorithms based on lifestyle changes/comorbidities.