Nonpolypoid colorectal neoplasms: Gender differences in prevalence and malignant potential

Abstract Objective. Colonoscopy may fail to prevent colorectal cancer, especially in the proximal colon and in women. Nonpolypoid colorectal neoplasms may potentially explain some of these post-colonoscopy cancers. In the present study, we aimed to examine the prevalence and malignant potential of nonpolypoid colorectal neoplasms in a large population, with special attention to gender and location. Methods. We performed a cross-sectional study of all consecutive patients undergoing elective colonoscopy at a single academic medical center. The endoscopists were familiarized on the detection and treatment of nonpolypoid lesions. Advanced histology was defined by the presence of high-grade dysplasia or early cancer. Results. We included 2310 patients (53.9% women, mean age 58.4 years) with 2143 colorectal polyps. Prevalences of colorectal neoplasms and nonpolypoid colorectal neoplasms were lower in women than in men (20.9% vs. 33.7%, p < 0.001 and 3.0% vs. 5.5%, p = 0.002). In women, nonpolypoid colorectal n...