Adenoma Detection Rate: I Will Show You Mine if You Show Me Yours

Narrow Band Imaging versus White Light for the Detection of Sessile Serrated Colorectal Lesions: A Randomized Clinical Trial

Background

Colorectal cancer (CRC) is a leading cause of cancer. The detection of pre-malignant lesions by colonoscopy is associated with reduced CRC incidence and mortality. Narrow band imaging has shown promising but conflicting results for the detection of serrated lesions.

Methods

We performed a randomized clinical trial to compare the mean detection of serrated lesions and hyperplastic polyps ≥10 mm with NBI or high-definition white light (HD-WL) withdrawal. We also compared all sessile serrated lesions (SSLs), adenoma, and polyp prevalence and rates.

Results

Overall, 782 patients were randomized (WL group 392 patients; NBI group 390 patients). The average number of serrated lesions and hyperplastic polyps ≥10 mm detected per colonoscopy (primary endpoint) was similar between the HD-WL and NBI group (0.118 vs. 0.156, p = 0.44). Likewise, the adenoma detection rate (55.2% vs. 53.2%, p = 0.58) and SSL detection rate (6.8% vs. 7.5%, p = 0.502) were not different between the two study groups. Withdrawal time was higher in the NBI group (10.88 vs. 9.47 min, p = 0.004), with a statistically nonsignificant higher total procedure time (20.97 vs. 19.30 min, p = 0.052).

Conclusions

The routine utilization of narrow band imaging does not improve the detection of serrated class lesions or any pre-malignant lesion and increases the withdrawal time.

Postcolonoscopy Colorectal Cancer in a Referral Center for Colorectal Cancer: Prevalence and Risk Factors

Background and Aims

Colonoscopy is effective to detect and remove colorectal lesions. However, after a negative colonoscopy, cancers could be detected during the interval follow-up. This study was designed to identify characteristics and risk factors for postcolonoscopy colorectal cancer - interval type.

Methods

Medical records of individuals who were newly diagnosed with colorectal cancer between January 2018 and December 2019 were reviewed. Clinical, demographic, and endoscopic variables were analyzed. Those with the diagnosis of colorectal cancer between two consecutive colonoscopies performed within the appropriated surveillance range were considered to have postcolonoscopy colorectal cancer - interval type. A comparison between the group of patients with non-postcolonoscopy colorectal cancer - interval type and the group of patients with postcolonoscopy colorectal cancer - interval type was then performed.

Results

During the study period, 491 patients were newly diagnosed with colorectal cancer. Among them, 61 (12.4%) had postcolonoscopy colorectal cancer - interval subtype. Postcolonoscopy colorectal cancer - interval type was three times more prevalent on the proximal colon (p = 0.014) and was associated with the presence of two or more cardiovascular risk factors (aOR = 4.25; p = 0.016), cholecystectomy in the past (aOR = 10.09; p = 0.019), and family history of colorectal cancer on a first-degree relative (aOR = 4.25; p = 0.006). Moreover, isolated cardiovascular risk factors revealed a protective effect for the absence of all cardiovascular risk factors (aOR = 20; p = 0.034). The ROC curve associated with the multivariate model revealed a predictive power of 77.8% (p < 0.001).

Conclusions

Postcolonoscopy colorectal cancer - interval type is more common in the proximal colon and in patients with a family history (first-degree relative) of colorectal cancer, two or more cardiovascular risk factors, and a history of cholecystectomy. All of these are easily detectable in clinical practice and may be of extreme importance in the control of postcolonoscopy colorectal cancer in the near future.

Participation in clinical trials increases the detection of pre-malignant lesions during colonoscopy

BACKGROUND

Colorectal adenoma detection has been associated with cancer prevention effectiveness. Clinical trials have been conceived to determine the role of several interventions to increase the detection of pre-malignant lesions. We hypothesized that colonoscopy in the setting of such trials have higher pre-malignant lesion detection rates.

METHODS

We performed a cross-sectional study comparing the detection of pre-malignant lesions in 147 randomly sampled non-research colonoscopies and 294 from the control groups of two prospective trials. We included outpatients aged 40-79 who had no personal history of CRC.

RESULTS

Baseline characteristics were similar between the two groups. The pre-malignant lesion detection rate in the trial vs control group was 65.6% vs 44.2% (OR 2.411; 95% CI 1.608-3.614; p<0.001), the polyp detection rate was 73.8% vs 59.9% (OR 1.889; 95% CI 1.242-2.876; p=0.003), the adenoma detection rate was 62.6% vs 44.2% (OR 2.110; 95% CI 1.411-3.155; p<0.001) and the sessile serrated lesion detection rate was 17% vs 4.1% (OR 4.816; 95% CI 2.014-11.515; p<0.001). The mean number of pre-malignant and sessile serrated lesions was 1.70 vs 1.06 (p=0.002) and 0.32 vs 0.06 (p=0.001) lesions per colonoscopy. In a multivariate analysis with each single potential confounder, there was no significant change in any of the study outcomes.

CONCLUSIONS

Patients involved in colonoscopy trials may benefit from higher quality examinations, as shown by the higher detection rates. Institutions should consider supporting clinical research in colonoscopy as a simple means to improve colonoscopy quality and colorectal cancer prevention.

Prevalence and Clinical Features of Sessile Serrated Polyps: A Systematic Review

BACKGROUND & AIMS

Sessile serrated polyps (SSPs) could account for a substantial proportion of colorectal cancers. We aimed to increase clarity on SSP prevalence and clinical features.

METHODS

We performed a systematic review of MEDLINE, Web of Science, Embase, and Cochrane databases for original studies published in English since 2000. We included studies of different populations (United States general or similar), interventions (colonoscopy, autopsy), comparisons (world regions, alternative polyp definitions, adenoma), outcomes (prevalence, clinical features), and study designs (cross-sectional). Random-effects regression was used for meta-analysis where possible.

RESULTS

We identified 74 relevant colonoscopy studies. SSP prevalence varied by world region, from 2.6% in Asia (95% confidence interval [CI], 0-5.9) to 10.5% in Australia (95% CI, 2.8-18.2). Prevalence values did not differ significantly between the United States and Europe (P = .51); the pooled prevalence was 4.6% (95% CI, 3.4-5.8), and SSPs accounted for 9.4% of polyps with malignant potential (95% CI, 6.6-12.3). The mean prevalence was higher when assessed through high-performance examinations (9.1%; 95% CI, 4.0-14.2; P = .04) and with an alternative definition of clinically relevant serrated polyps (12.3%; 95% CI, 9.3-15.4; P < .001). Increases in prevalence with age were not statistically significant, and prevalence did not differ significantly by sex. Compared with adenomas, a higher proportion of SSPs were solitary (69.0%; 95% CI, 45.9-92.1; P = .08), with diameters of 10 mm or more (19.3%; 95% CI, 12.4-26.2; P = .13) and were proximal (71.5%; 95% CI, 63.5-79.5; P = .008). The mean ages for detection of SSP without dysplasia, with any or low-grade dysplasia, and with high-grade dysplasia were 60.8 years, 65.6 years, and 70.2 years, respectively. The range for proportions of SSPs with dysplasia was 3.7%-42.9% across studies, possibly reflecting different study populations.

CONCLUSIONS

In a systematic review, we found that SSPs are relatively uncommon compared with adenoma. More research is needed on appropriate diagnostic criteria, variations in detection, and long-term risk.

Relationship between the endoscopic withdrawal time and adenoma/polyp detection rate in individual colonic segments: a KASID multicenter study

BACKGROUND AND AIMS

Appropriate colonoscopy withdrawal times for individual colonic segments are not well known. The relationship between withdrawal time and adenoma detection rate (ADR)/polyp detection rate (PDR) in individual colonic segments was examined in this study.

METHODS

This was a prospective observational study involving 724 patients who underwent colonoscopy screening or surveillance colonoscopy from October 2015 to February 2017 at 10 university hospitals.

RESULTS

In the right side of the colon, the ADR (33.2% vs 13.7%, P < .001), PDR, serrated polyp detection rate, and number of adenomas per colonoscopy (APC) were significantly higher when the colonoscopy withdrawal time was ≥2 minutes compared with <2 minutes. When the withdrawal time was ≥4 minutes in the proximal colon and ≥3 minutes in the left segment of the colon, the ADR, PDR, and APC were significantly higher compared with withdrawal times of <4 minutes and <3 minutes, respectively. Multivariate analyses showed that the ADR was significantly associated with withdrawal times of ≥2 minutes in the right side of the colon (odds ratio [OR], 2.98; 95% confidence interval [CI], 1.72-5.15; P < .001), ≥4 minutes in the proximal colon (OR, 4.48; 95% CI, 3.15-6.36; P < .001), and ≥3 minutes in the left segment of the colon (OR, 2.92; 95% CI, 1.74-4.91; P < .001).

CONCLUSIONS

The PDR and ADR appeared to be significantly increased when the withdrawal time was ≥2 minutes in the right-sided colon segment, ≥4 minutes in the proximal colon, and ≥3 minutes in the left-sided colon segment compared with shorter withdrawal times.

Do we really need an anesthesiologist for routine colonoscopy in American Society of Anesthesiologist 1 and 2 patients?

PURPOSE OF REVIEW

In an era where healthcare costs are being heavily scrutinized, every expenditure is reviewed for medical necessity. Multiple national gastroenterology societies have issued statements regarding whether an anesthesiologist is necessary for routine colonoscopies in American Society of Anesthesiologist (ASA) 1 and 2 patients.

RECENT FINDINGS

A large percentage of patients are undergoing screening colonoscopy without any sedation at all, which would not require an independent practitioner to administer medications. Advances in technique and technology are making colonoscopies less stimulating. Advantages to administering sedation, including propofol, have been seen even when not administered under the direction of an anesthesiologist and complications seem to be rare. The additional cost of having monitored anesthesia care appears to be a driving factor in whether a patient receives it or not.

SUMMARY

A large multiinstitutional randomized control trial would be necessary to rule out potential confounders and to determine whether there is a safety benefit or detriment to having anesthesiologist-directed care in the setting of routine colonoscopies in ASA 1 and 2 patients. Further discussion would be necessary regarding what the monetary value of that effect is if a small difference were to be detected.