Association of smoking and flat adenomas: results from an asymptomatic population screened with a high-definition colonoscope

Abstract

Background-Flat adenomas represent a morphologically distinct class of polyps that may be difficult to detect but little is known regarding risk factors for these lesions. Identification of risk factors for these lesions may aid in colorectal cancer (CRC) screening since patients at risk for these lesions may require special imaging techniques. Smoking, an important risk factor for CRC, may be associated with molecular changes that increase the risk for flat adenomas.

The Increased Risk of Colon Cancer Due to Cigarette Smoking May Be Greater in Women than Men

“…Also, smoking has been shown to be associated with flat colorectal adenomas, which were located mainly in proximal colon (30). Recently, cigarette smoking has been shown to be strongly associated with molecularly defined subtypes of colorectal cancer, such as MSI-high, CIMP-positive, and BRAF mutation-positive, that originate through epigenetically mediated carcinogenic pathways.…”

Smoking and the Association of Advanced Colorectal Neoplasia in an Asymptomatic Average Risk Population: Analysis of Exposure and Anatomical Location in Men and Women

“…We observed that female and not male smokers were at risk for proximal advanced neoplasia. It has been shown that smoking may be associated with flat polyps [42] as well as serrated tissue [43], both of which can be proximal in location and difficult to detect and thus may explain the rightsided paradox. Serrated polyps have an increased frequency of BRAF mutations [44] which along with other methylation abnormalities have been observed in interval cancers [45,46] and in smokers [47].…”

Higher adenoma detection rates with cap-assisted colonoscopy: a randomised controlled trial

“…Right-sided polyps were those that were proximal to the splenic flexure. We used the polyp morphology classification system described by the Japanese Society for Cancer of the Colon and Rectum27 that has been used by others 28 29. This classification divides the polyps into two broad categories—polypoid and non-polypoid varieties.…”