Colonoscopy Quality is the Answer for the Emerging Issue of Interval Cancer

Abstract

Colonoscopy is currently regarded as the gold standard and preferred screening method for colorectal cancer (CRC). Recently, however, a limitation of colonoscopy in the prevention of CRCs has been identified, particularly in the right-sided colon, and the problem of so-called interval cancers has emerged. The prevalence of interval cancer is estimated to be between 4% and 8% of CRCs detected. Although the exact etiology of interval cancer remains unknown, factors implicated in the development of interval cancers include missed lesions at the time of colonoscopy, incomplete resection of previous neoplastic lesions, different tumor biology, and serrated pathway of carcinogenesis. However, recent evidence suggests that interval cancers are related to the training of the endoscopist and quality of the colonoscopy rather than tumor biology. Therefore, the importance of adequate training and continuous monitoring of the colonoscopy quality, which are amenable to improvement, cannot be overstated in order to prevent the risk of interval cancers. In this study, the current literature regarding the prevalence and potential factors related to interval cancers and colonoscopy quality-related issues are reviewed.

Do surveillance intervals in patients with more than five adenomas at index colonoscopy be shorter than those in patients with three to four adenomas? A Korean Association for the Study of Intestinal Disease study

“…When five polyps were found, the miss rate of polyps was increased by 4.48 times (95% CI, 1.91–10.5) . However, although interval cancers could arise from missed lesions, as most missed polyps were non‐neoplastic polyps or hyperplastic neoplasia, there was no concern of malignant transformation of these polyps in a short period, when quality of colonoscopy was appropriate …”

Microsatellite Instability Status of Interval Colorectal Cancers in a Korean Population

“…MSI, even in patients without Lynch syndrome is associated with proximal tumor location and improved survival compared with MSS cancers and more rapid lesion growth 20,21. Tumors that arise from sessile serrated polyps also may contribute to interval cancers because of their proximal colon predominance and difficulty of detection at colonoscopy 1,22. These flat-type lesions in particular have a tendency to invade the submucosal layer even when they are small.…”

Characteristics of the Patients Undergoing Colonoscopy in a Single Center within an 8-year Period

“…Colonoscopy, which is accepted as the gold standard method for the examination of colon mucosa, allows for both performing a biopsy for diagnostic purposes and interventions (polypectomy, stopping bleeding, etc.) for the lesions [3,4]. On the other hand, the success of a colonoscopy depends on a good preparation phase and largely on the skills of the team performing the procedure [5,6].…”