Colorectal Endoscopy, Advanced Adenomas, and Sessile Serrated Polyps: Implications for Proximal Colon Cancer

Abstract

OBJECTIVES Colonoscopy is associated with a decreased risk of colorectal cancer but may be more effective in reducing the risk of distal than proximal malignancies. To gain insight into the differences between proximal and distal colon endoscopic performance, we conducted a case-control study of advanced adenomas, the primary targets of colorectal endoscopy screening, and sessile serrated polyps (SSPs), newly recognized precursor lesions for a colorectal cancer subset that occurs most often in the proximal colon. METHODS The Group Health-based study population included: 213 advanced adenoma cases, 172 SSP cases, and 1,704 controls ages 50–79, who received an index colonoscopy from 1998–2007. All participants completed a structured questionnaire covering endoscopy history. Participants with polyps underwent a standard pathology review to confirm the diagnosis and reclassify a subset as advanced adenomas or SSPs. Logistic regression analyses were conducted to estimate adjusted odds ratios (OR) and 95% confidence intervals (CI) for the association between endoscopy and advanced adenomas and SSPs separately; site-specific analyses were completed. RESULTS Previous endoscopy was associated with decreased risk of advanced adenomas in both the rectum/distal colon (OR=0.38; 95% CI: 0.26–0.56) and proximal colon (OR=0.31; 95% CI: 0.19–0.52), but there was no statistically significant association between prior endoscopy and SSPs (OR=0.80; 95%CI: 0.56–1.13). CONCLUSIONS Our results support the hypothesis that the effect of endoscopy differs between advanced adenomas and SSPs. This may have implications for proximal colon cancer prevention and be due to the failure of endoscopy to detect/remove SSPs, or the hypothesized rapid development of SSPs.

Prevalence and Characteristics of Colorectal Polyps in Symptomatic and Asymptomatic Iranian Patients Undergoing Colonoscopy from 2009-2013

“…Among screening methods colonoscopy remains the best technics to detect the high risk patients. study on 213 advanced adenomas and 172 sessile serrated polyps(SSP) patients In 2012 revealed that previous endoscopy had a significant decrease in development of advanced adenoma in both the rectum/ distal colon and proximal colon but their findings wasn't significant in SSps cases (Burnett-Hartman et al, 2012) Most of the polyps in our study located in rectosigmoid (63.1%). This is similar to study of Bafandeh et al (2008), Mirzaie et al (2012) and Hodadoostan et al (2010) in which they found rectum and sigmoid together the most common site of the lesions in Iranian patients with colon polyps.…”

Impact of fair bowel preparation quality on adenoma and serrated polyp detection: data from the New Hampshire Colonoscopy Registry by using a standardized preparation-quality rating

“…A recent study found that colonoscopy conferred a statistically significant reduction in the future risk of proximal advanced adenomas, but not proximal sessile serrated polyps. 27 It is unclear whether inadequate colonic preparation in the proximal colon might have played a role in this finding. To date, there have been little data in the medical literature regarding ADR and SDR in the proximal colon of patients with inadequate or suboptimal preparations, leading to our current investigation.…”

Multi-Target Stool DNA Test: A New High Bar for Noninvasive Screening

“…Importantly, fecal blood tests fail entirely to detect the subset of sessile serrated polyps [4,43], lesions which are also often missed by colonoscopy and may help to explain its lesser effect on proximal disease [58].…”