Early detection of and screening for colorectal neoplasia

Abstract

There are approximately one million new cases of colorectal cancer (CRC) per year worldwide, with substantial associated morbidity and mortality. The long natural history of colorectal neoplasia affords the opportunity to use preventive measures to improve survival in this disease. Currently screening for adenomatous polyps and early-stage cancers is the best methodology for improving survival. The increasing knowledge of CRC pathogenesis and its natural history is allowing the development of new tools to identify patients who will benefit most from colon cancer screening and the defining of appropriate surveillance intervals. The guidelines for screening for colorectal neoplasia have recently been substantially revised by several organizations based on developing technologies and a growing body of data on the efficacy of CRC screening.

Keywords: Adenoma; Colon cancer screening; Colonoscopy; Computed tomographic colonography; Fecal occult blood testing.

Fig. 1

CT colonography ("virtual colonoscopy"). (A) Two-dimensional CT image of an annular CRC. (B) Three-dimensional reconstruction of image in A. (C) Large sessile colon polyp evident in colonoscopy. (D) Three-dimensional image of lesion in C obtained by CT colonography.