Flat Lesions Becoming More Prevalent in the U.S.

Many have thought that nonpolypoid (flat) colorectal neoplasms were limited to the Japanese population, but there is increasing recognition that these lesions now are prevalent in Western populations. Recently published data have highlighted the prevalence of flat and depressed lesions in the U.S. population and risk for high-grade dysplasia and invasive cancer that is associated with such lesions (Gastroenterology 2006; 130:566).

Now, researchers have performed a high-profile study involving 1819 patients who underwent elective colonoscopies at a California Veterans Affairs hospital from June 2003 to June 2004. The study population was divided into three groups: an asymptomatic screening group, a surveillance group with family histories of …