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 neoplasms were significantly more likely to contain advanced histology than polypoid ones (OR 2.89, 95% CI 1.24–6.74, p = 0.01), while this was not the case in men (OR 0.91, 95% CI 0.40–2.06, p = 0.83). Proximal neoplasms with advanced histology were more likely to be nonpolypoid than distal ones (OR 4.68, 95% CI 1.54–14.2, p = 0.006). Conclusion. Nonpolypoid mechanisms may play an important role in colorectal carcinogenesis, in both women and men. Although women have fewer colorectal neoplasms than men, they have nonpolypoid colorectal neoplasms, which frequently contain advanced histology.

Key Words::

• adenoma
• advanced histology
• colorectal
• flat
• gender
• location
• neoplasm
• nonpolypoid
• women

Acknowledgments

We are grateful to all endoscopists, faculties, and trainees, as well as nurses at the endoscopy unit of the Maastricht University Medical Center for their contribution to build up this cohort. Ethics approval: This study was approved by the Institutional Review Board of the Maastricht University Medical Center (MEC 08-4-074) and registered in the Dutch trial registry: (http://www.trialregister.nl/trialreg/admin/rctview.asp?TC=1891).

Declaration of interest: E. J. A. Rondagh was the recipient of an unrestricted educational grant from Pentax B.V., The Netherlands. Pentax B.V. had no role in the design of the study, data collection, analysis and interpretation, writing of the manuscript, or decision to submit for publication. The other authors have nothing to disclose.