Defeating Cancer by Boosting the Adenoma Detection Rate: The Circle of Life

Sessile serrated lesion detection rates during average risk screening colonoscopy: A systematic review and meta-analysis of the published literature

Background and study aims  Sessile serrated lesion (SSL) detection rate has been variably reported and unlike adenoma detection rate (ADR) is not currently a quality indicator for screening colonoscopy. Composite detection rates of SSL in patients undergoing average risk screening colonoscopy are not available. Methods  Electronic database search (Medline, Embase and Cochrane) was conducted for studies reporting detection rates of serrated polyps (SSL, Hyperplastic polyp, traditional serrated adenoma) among average risk subjects undergoing screening colonoscopy. Primary outcomes were pooled SDR (SSL detection rate) and proximal serrated polyp detection rate (PSPDR). Pooled proportion rates were calculated with 95 %CI with assessment of heterogeneity (I ² ). Publication bias, regression test and 95 %prediction interval were calculated. Results  A total of 280,370 screening colonoscopies among average risk subjects that were eligible with 48.9 % males and an average age of 58.7 years (± 3.2). The pooled SDR was available from 16 studies: 2.5 % (1.8 %-3.4 %) with significant heterogeneity (I ²  = 98.66 %) and the 95 % prediction interval ranging from 0.6 % to 9.89 %. When analysis was restricted to large (n > 1000) and prospective studies (n = 4), SDR was 2 % (1.1 %-3.3 %). Pooled PSPDR was 10 % (8.5 %-11.8 %; 12 studies). There was evidence of publication bias ( P  < 0.01). Conclusion  Definitions of SSL have been varying over years and there exists significant heterogeneity in prevalence reporting of serrated polyps during screening colonoscopy. Prevalence rate of 2 % for SSL and 10 % for proximal serrated polyps could serve as targets while robust high-quality data is awaited to find a future benchmark showing reduction in colorectal cancer arising from serrated pathway.

Efficacy of Per-oral Methylene Blue Formulation for Screening Colonoscopy

BACKGROUND & AIMS

Topically applied methylene blue dye chromoendoscopy is effective in improving detection of colorectal neoplasia. When combined with a pH- and time-dependent multimatrix structure, a per-oral methylene blue formulation (MB-MMX) can be delivered directly to the colorectal mucosa.

METHODS

We performed a phase 3 study of 1205 patients scheduled for colorectal cancer screening or surveillance colonoscopies (50-75 years old) at 20 sites in Europe and the United States, from December 2013 through October 2016. Patients were randomly assigned to groups given 200 mg MB-MMX, placebo, or 100 mg MB-MMX (ratio of 2:2:1). The 100-mg MB-MMX group was included for masking purposes. MB-MMX and placebo tablets were administered with a 4-L polyethylene glycol-based bowel preparation. The patients then underwent colonoscopy by an experienced endoscopist with centralized double-reading. The primary endpoint was the proportion of patients with 1 adenoma or carcinoma (adenoma detection rate [ADR]). We calculated odds ratios (ORs) and 95% confidence intervals (CIs) for differences in detection between the 200-mg MB-MMX and placebo groups. False-positive (resection rate for non-neoplastic polyps) and adverse events were assessed as secondary endpoints.

RESULTS

The ADR was higher for the MB-MMX group (273 of 485 patients, 56.29%) than the placebo group (229 of 479 patients, 47.81%) (OR 1.46; 95% CI 1.09-1.96). The proportion of patients with nonpolypoid lesions was higher in the MB-MMX group (213 of 485 patients, 43.92%) than the placebo group (168 of 479 patients, 35.07%) (OR 1.66; 95% CI 1.21-2.26). The proportion of patients with adenomas ≤5 mm was higher in the MB-MMX group (180 of 485 patients, 37.11%) than the placebo group (148 of 479 patients, 30.90%) (OR 1.36; 95% CI 1.01-1.83), but there was no difference between groups in detection of polypoid or larger lesions. The false-positive rate did not differ significantly between groups (83 [23.31%] of 356 patients with non-neoplastic lesions in the MB-MMX vs 97 [29.75%] of 326 patients with non-neoplastic lesions in the placebo group). Overall, 0.7% of patients had severe adverse events but there was no significant difference between groups.

CONCLUSIONS

In a phase 3 trial of patients undergoing screening or surveillance colonoscopies, we found MB-MMX led to an absolute 8.5% increase in ADR, compared with placebo, without increasing the removal of non-neoplastic lesions. Clinicaltrials.gov no: NCT01694966.

The Natural History of Colorectal Polyps: Overview of Predictive Static and Dynamic Features

For decades, colorectal screening strategies have been largely driven by static features, particularly polyp size. Although cross-sectional features of polyp size, morphology, and location are important determinants of clinical relevance before histology, they lack any dynamic information on polyp growth rates. Computed tomography colonography allows for in vivo surveillance of colorectal polyps, providing volumetric growth rates that are providing new insights into tumorigenesis. In this article, existing cross-sectional and longitudinal data on colorectal polyps are reviewed, with an emphasis on how these features may affect clinical relevance and patient management.