The Efficacy of Real-time Computer-aided Detection of Colonic Neoplasia in Community Practice: A Pragmatic Randomized Controlled Trial

BACKGROUND & AIMS

The use of computer-aided detection (CADe) has increased the adenoma detection rates (ADRs) during colorectal cancer (CRC) screening/surveillance in randomized controlled trials (RCTs) but has not shown benefit in real-world implementation studies. We performed a single-center pragmatic RCT to evaluate the impact of real-time CADe on ADRs in colonoscopy performed by community gastroenterologists.

METHODS

We enrolled 1100 patients undergoing colonoscopy for CRC screening, surveillance, positive fecal-immunohistochemical tests, and diagnostic indications at one community-based center from September 2022 to March 2023. Patients were randomly assigned (1:1) to traditional colonoscopy or real-time CADe. Blinded pathologists analyzed histopathologic findings. The primary outcome was ADR (the percentage of patients with at least 1 histologically proven adenoma or carcinoma). Secondary outcomes were adenomas detected per colonoscopy (APC), sessile-serrated lesion detection rate, and non-neoplastic resection rate.

RESULTS

The median age was 55.5 years (interquartile range, 50-62 years), 61% were female, 72.7% were of Hispanic ethnicity, and 9.1% had inadequate bowel preparation. The ADR for the CADe group was significantly higher than the traditional colonoscopy group (42.5% vs 34.4%; P = .005). The mean APC was significantly higher in the CADe group compared with the traditional colonoscopy group (0.89 ± 1.46 vs 0.60 ± 1.12; P < .001). The improvement in adenoma detection was driven by increased detection of <5 mm adenomas. CADe had a higher sessile-serrated lesion detection rate than traditional colonoscopy (4.7% vs 2.0%; P = .01). The improvement in ADR with CADe was significantly higher in the first half of the study (47.2% vs 33.7%; P = .002) compared with the second half (38.7% vs 34.9%; P = .33).

CONCLUSIONS

In a single-center pragmatic RCT, real-time CADe modestly improved ADR and APC in average-detector community endoscopists. (ClinicalTrials.gov number, NCT05963724).

Missed Opportunities: the Timing and Frequency of Screening Colonoscopy in Patients That Develop Esophageal Adenocarcinoma

INTRODUCTION

Screening colonoscopy (SC) is widely accepted and has been shown to decrease the rate of colorectal cancer death. Guidelines and acceptance of screening for Barrett's esophagus (BE) are less established despite the fact that esophageal adenocarcinoma (EA) remains the fastest increasing cancer in the USA. The aim of this study was to assess the timing and frequency of SC in patients ultimately found to have EA and to evaluate the presence of symptoms and risk factors that might have prompted an esophagogastroduodenoscopy (EGD) and potentially earlier diagnosis of the EA.

METHODS

A retrospective chart review was performed to identify all patients who were referred to a single center with esophageal cancer between July 2016 and November 2022. Patients with any histology other than adenocarcinoma were excluded.

RESULTS

There were 221 patients referred with EA. Of these, a SC had been done prior to the diagnosis of EA in 108 patients (49%): 96 men and 12 women. A total of 203 SC had been done (range 1-7 per patient), and 47% of patients had more than 1 SC. The median interval from the last SC to the diagnosis of EA was 2.9 years. At the time of SC, gastroesophageal reflux disease (GERD) symptoms or chronic acid suppression medication use was reported by 81% of patients, and 80% had an American Society of Gastrointestinal Endoscopy (ASGE) indication for a screening EGD. Only 19 patients (18%) that had a SC had an EGD at any time prior to the diagnosis of EA, and in these patients, 74% had erosive esophagitis or BE. The EA in most patients was stage III or IV and associated with lymph node metastases.

CONCLUSIONS

Nearly one-half of patients ultimately diagnosed with EA had one or more SCs, and most of these patients had GERD symptoms, were using acid suppression medications or had an ASGE indication for a screening EGD. Despite this, only 18% had an EGD prior to the EA diagnosis. The addition of an EGD at the time of SC in these patients may have allowed the detection of BE or EA at an early, endoscopically curable stage and represents a missed opportunity to intervene in the natural history of this disease.

An Evaluation of Critical Factors for the Cost-Effectiveness of Real-Time Computer-Aided Detection: Sensitivity and Threshold Analyses Using a Microsimulation Model

BACKGROUND

The use of computer-aided detection (CAD) increases the adenoma detection rates (ADRs) during colorectal cancer (CRC) screening/surveillance. This study aimed to evaluate the requirements for CAD to be cost-effective and the impact of CAD on adenoma detection by endoscopists with different ADRs.

METHODS

We developed a semi-Markov microsimulation model to compare the effectiveness of traditional colonoscopy (mean ADR, 26%) to colonoscopy with CAD (mean ADR, 37%). CAD was modeled as having a $75 per-procedure cost. Extensive 1-way sensitivity and threshold analysis were performed to vary cost and ADR of CAD. Multiple scenarios evaluated the potential effect of CAD on endoscopists' ADRs. Outcome measures were reported in incremental cost-effectiveness ratios, with a willingness-to-pay threshold of $100,000/quality-adjusted life year.

RESULTS

When modeling CAD improved ADR for all endoscopists, the CAD cohort had 79 and 34 fewer lifetime CRC cases and deaths, respectively, per 10,000 persons. This scenario was dominant with a cost savings of $143 and incremental effectiveness of 0.01 quality-adjusted life years. Threshold analysis demonstrated that CAD would be cost-effective up to an additional cost of $579 per colonoscopy, or if it increases ADR from 26% to at least 30%. CAD reduced CRC incidence and mortality when limited to improving ADRs for low-ADR endoscopists (ADR <25%), with 67 fewer CRC cases and 28 CRC deaths per 10,000 persons compared with traditional colonoscopy.

CONCLUSIONS

As CAD is implemented clinically, it needs to improve mean ADR from 26% to at least 30% or cost less than $579 per colonoscopy to be cost-effective when compared with traditional colonoscopy. Further studies are needed to understand the impact of CAD on community practice.

Adenoma and Sessile Serrated Lesion Detection Rates at Screening Colonoscopy for Ages 45-49 Years vs Older Ages Since the Introduction of New Colorectal Cancer Screening Guidelines

BACKGROUND AND AIMS

All major U.S. guidelines now endorse average-risk colorectal cancer (CRC) screening at 45-49 years of age. Concerns exist that endoscopic capacity may be strained, that low-risk persons may self-select for screening, and that calculations of the adenoma detection rate may be diluted. We analyzed age-specific screening colonoscopy volumes and lesion detection rates before vs after the endorsement of CRC screening at 45-49 years of age.

METHODS

We compared colonoscopy volumes and lesion detection rates in our healthcare system during period 1 (October 2017 to December 2018), before the first change in guidelines, vs period 2 (January 2019 to August 2021), the era of new guidelines.

RESULTS

The proportion of first-time screening colonoscopies performed in 45- to 49-year-olds increased from 3.5% to 11.6% (relative risk, 3.36; 95% CI, 2.45-4.61). The period 2 detection rates for adenoma, advanced adenoma, sessile serrated lesion, advanced sessile serrated lesion, adenomas per colonoscopy, and lesions per colonoscopy were very similar for 45- to 49-year-olds (34.3%, 6.3%, 8.6%, 2.9%, 0.58, and 0.69, respectively) and 50- to 54-year-olds (38.2%, 5.8%, 9.4%, 3.0%, 0.63, and 0.76, respectively) at first-time screening, and for 60- to 64-year-olds at rescreening (33.4%, 6.1%, 7.2%, 2.3%, 0.61, and 0.70, respectively). All detection rates, adenomas per colonoscopy, and lesions per colonoscopy increased from period 1 to period 2 (eg, overall adenoma detection rate 35.1% vs 42.6%; P < .0001), without any decreases among 45- to 49-year-olds.

CONCLUSIONS

In our healthcare system, a lower CRC screening initiation age has modestly affected colonoscopy volume by age without compromising screening yield. Lesion detection rates, including for advanced adenomas, in average-risk 45- to 49-year-olds approximate those in 50- to 54-year-olds at first-time screening and 60- to 64-year-olds at rescreening. National monitoring is needed to assess fully the impact of lowering the CRC screening initiation age.

Adenoma Detection Rate (ADR) Irrespective of Indication Is Comparable to Screening ADR: Implications for Quality Monitoring

BACKGROUND & AIMS

Adenoma detection rate (ADR) is a key measure of colonoscopy quality. However, efficient measurement of ADR can be challenging because many colonoscopies are performed for non-screening purposes. Measuring ADR without being restricted to screening indication may likely facilitate more widespread implementation of quality monitoring. We hypothesized that the ADR for all colonoscopies, irrespective of the indication, would be equivalent to the ADR for screening colonoscopies.

METHODS

We reviewed consecutive colonoscopies at two Veterans Affairs centers performed by 21 endoscopists over 6 months in 2015. We calculated the ADR for screening exams, non-screening (surveillance and diagnostic) exams, and all exams (irrespective of indication), correcting for within-endoscopist correlation. We then performed simulation modeling to calculate the ADRs under 16 hypothetical scenarios of various indication distributions. We simulated 100,000 trials with 3,000 participants, randomly assigned indication (screening, surveillance, diagnostic, and FIT+) from a multinomial distribution, randomly drew adenoma using the observed ADRs per indication, and calculated 95% confidence intervals of the mean differences in ADR of screening and non-screening indications.

RESULTS

Among 2628 colonoscopies performed by 21 gastroenterologists, the indication was screening in 28.9%, surveillance in 48.2% and diagnostic in 22.9%. There was no significant difference in the ADR, 50% (95%CI: 45-56%) for all colonoscopies vs 49% (95%CI: 43-56%) for screening exams (p=.55). ADRs were 56% for surveillance and 38% for diagnostic exams. In our simulation modeling, only one out of 16 scenarios (screening 10%, surveillance 70%, diagnostic 10% and FIT+ 10%) resulted in a significant difference between the calculated ADRs for screening and non-screening indications.

CONCLUSIONS

In our study, the overall ADR computed from all colonoscopies was not significantly different than the conventional ADR based on screening colonoscopies. Assessing ADR for colonoscopy irrespective of indication may be adequate for quality monitoring, and could facilitate the implementation of quality measurement and reporting. Future prospective studies should evaluate the validity of using overall ADR for quality reporting in other jurisdictions before adopting this method in clinical practice.

Association of Adenoma Detection Rate and Adenoma Characteristics With Colorectal Cancer Mortality After Screening Colonoscopy

BACKGROUND & AIMS

The adenoma detection rate (ADR) and characteristics of previously resected adenomas are associated with colorectal cancer (CRC) incidence and mortality. However, the combined effect of both factors on CRC mortality is unknown.

PATIENTS AND METHODS

Using data of the Austrian quality assurance program for screening colonoscopy, we evaluated the combined effect of ADR and lesion characteristics on subsequent risk for CRC mortality. We analyzed mortality rates for individuals with low-risk adenomas (1-2 adenomas <10 mm), individuals with high-risk adenomas (advanced adenomas or ≥3 adenomas), and after negative colonoscopy (negative colonoscopy or small hyperplastic polyps) performed by endoscopists with an ADR <25% compared with ≥25%. Cox regression was used to determine the association of combined risk groups with CRC mortality, adjusted for age and sex.

RESULTS

We evaluated 259,885 colonoscopies performed by 361 endoscopists. A total of 165 CRC-related deaths occurred during the follow-up period, up to 12.2 years. In all risk groups, CRC mortality was higher when colonoscopy was performed by an endoscopist with an ADR <25%. Compared with negative colonoscopy with an ADR ≥25%, CRC mortality was similar for individuals with low-risk adenomas irrespective of ADR (for ADR ≥25%: adjusted hazard ratio [HR], 1.22; 95% confidence interval [CI], 0.59-2.49; for ADR <25%: adjusted HR, 1.25; 95% CI, 0.64-2.43) and after negative colonoscopy with ADR <25% (adjusted HR, 1.27; 95% CI, 0.81-2.00). Individuals with high-risk adenomas were at significantly higher risk for CRC death if colonoscopy was performed by an endoscopist with an ADR <25% (adjusted HR, 2.25; 95% CI, 1.18-4.31) but not if performed by an endoscopist with an ADR ≥25% (adjusted HR, 1.35; 95% CI, 0.61-3.02).

CONCLUSIONS

Our study adds important evidence for mandatory assessment and monitoring of performance quality in screening colonoscopy. High-quality colonoscopy was associated with a lower risk for CRC death, and the impact of ADR was strongest for individuals with high-risk adenomas.

Colonoscopist Performance and Colorectal Cancer Risk After Adenoma Removal to Stratify Surveillance: Two Nationwide Observational Studies

BACKGROUND AND AIMS

Colonoscopy surveillance after adenoma removal is an increasing burden in many countries. Surveillance recommendations consider characteristics of removed adenomas, but not colonoscopist performance. We investigated the impact of colonoscopist performance on colorectal cancer risk after adenoma removal.

METHODS

We compared colorectal cancer risk after removal of high-risk adenomas, low-risk adenomas, and after negative colonoscopy for all colonoscopies performed by colonoscopists with low vs high performance quality (adenoma detection rate <20% vs ≥20%) in the Polish screening program between 2000 and 2011, with follow-up until 2017. Findings were validated in the Austrian colonoscopy screening program.

RESULTS

A total of 173,288 Polish colonoscopies were included in the study. Of 262 colonoscopists, 160 (61.1%) were low performers, and 102 (38.9%) were high performers; 11.1% of individuals had low-risk and 6.6% had high-risk adenomas removed at screening; 82.2% had no adenomas. During 10 years of follow-up, 443 colorectal cancers were diagnosed. For low-risk adenoma individuals, colorectal cancer incidence was 0.55% (95% confidence interval [CI] 0.40-0.75) with low-performing colonoscopists vs 0.22% (95% CI 0.14-0.34) with high-performing colonoscopists (hazard ratio [HR] 2.35; 95% CI 1.31-4.21; P = .004). For individuals with high-risk adenomas, colorectal cancer incidence was 1.14% (95% CI 0.87-1.48) with low-performing colonoscopists vs 0.43% (95% CI 0.27-0.69) with high-performing colonoscopists (HR 2.69; 95% CI 1.62-4.47; P < .001). After negative colonoscopy, colorectal cancer incidence was 0.30% (95% CI 0.27-0.34) for individuals examined by low-performing colonoscopists, vs 0.15% (95% CI 0.11-0.20) for high-performing (HR 2.10; 95% CI 1.52-2.91; P < .001). The observed trends were reproduced in the Austrian validation cohort.

CONCLUSIONS

Our results suggest that endoscopist performance may be an important contributor in addition to polyp characteristics in determining colorectal cancer risk after colonoscopy screening.

Participation in Competing Strategies for Colorectal Cancer Screening: A Randomized Health Services Study (PICCOLINO Study)

BACKGROUND & AIMS

Primary colonoscopy and fecal immunochemical testing (FIT) are considered first-tier tests for colorectal cancer (CRC) screening. Although colonoscopy is considered the most efficacious test, FIT might achieve higher participation rates. It is uncertain what the best strategy is for offering population-wide CRC screening.

METHODS

This was a multicenter randomized health services study performed within the framework of the Polish Colonoscopy Screening Program between January 2019 and March 2020 on screening-naïve individuals. Eligible candidates were randomly assigned in a 1:1:1 ratio to participate in 1 of 3 competing invitation strategies: control (invitation to screening colonoscopy only); sequential (invitation to primary colonoscopy and invitation for FIT for initial nonresponders); or choice (invitation offering a choice of colonoscopy or FIT). The primary outcome was participation in CRC screening within 18 weeks after enrollment into the study. The secondary outcome was diagnostic yield for advanced neoplasia.

RESULTS

Overall, 12,485 individuals were randomized into the 3 study groups. The participation rate in the control group (17.5%) was significantly lower compared with the sequential (25.8%) and choice strategy (26.5%) groups (P < .001 for both comparisons). The colonoscopy rates for participants with positive FITs were 70.0% for the sequential group and 73.3% for the choice group, despite active call-recall efforts. In the intention-to-screen analysis, advanced neoplasia detection rates were comparable among the control (1.1%), sequential (1.0%), and choice groups (1.1%).

CONCLUSIONS

Offering a combination of FIT and colonoscopy as a sequential or active choice strategy increases participation in CRC screening. Increased participation in strategies with FIT do not translate into higher detection of advanced neoplasia. ClinicalTrials.gov, Number NCT03790475.

Risk of Malignancy in Adenomas Detected During Screening Colonoscopy

BACKGROUND & AIMS

A higher incidence of proximal interval cancers after colonoscopy has been reported in several follow-up studies. One possible explanation for this might be that proximally located adenomas have greater malignant potential. The aim of the present study was to assess the risk of malignancy in proximal versus distal adenomas in patients included in a large screening colonoscopy database; adenoma shape and the patients' age and sex distribution were also analyzed.

METHODS

Data for 2007-2012 from the German National Screening Colonoscopy Registry, including 594,614 adenomas identified during 2,532,298 screening colonoscopies, were analyzed retrospectively. The main outcome measure was the rate of high-grade dysplasia (HGD) in adenomas, used as a surrogate marker for the risk of malignancy. Odds ratios (ORs) for the rate of HGD found in adenomas were analyzed in relation to patient- and adenoma-related factors using multivariate analysis.

RESULTS

HGD histology was noted in 20,873 adenomas (3.5%). Proximal adenoma locations were not associated with a higher HGD rate. The most significant risk factor for HGD was adenoma size (OR 10.36 ≥1 cm vs <1 cm), followed by patient age (OR 1.26 and 1.46 for age groups 65-74 and 75-84 vs 55-64 years) and sex (OR 1.15 male vs female). In comparison with flat adenomas as a reference lesion, sessile lesions had a similar HGD rate (OR 1.02) and pedunculated adenomas had a higher rate (OR 1.23). All associations were statistically significant (P ≤ .05).

CONCLUSIONS

In this large screening database, it was found that the rates of adenomas with HGD are similar in the proximal and distal colon. The presence of HGD as a risk marker alone does not explain higher rates of proximal interval colorectal cancer. We suggest that certain lesions (flat, serrated lesions) may be missed in the proximal colon and may acquire a more aggressive biology over time. A combination of endoscopy-related factors and biology may therefore account for higher rates of proximal versus distal interval colorectal cancer.

Simplifying Resect and Discard Strategies for Real-Time Assessment of Diminutive Colorectal Polyps

BACKGROUND & AIMS

During endoscopy, the resect and discard strategy, if performed with high confidence, can be used to determine histologic features of diminutive colorectal polyps (5 mm or less). These polyps can then be removed and discarded without pathology assessment. However, the complexities of real-time optical assessment and follow-up management have provided challenges to widespread use of this approach. We aimed to determine the outcomes of simple alternative strategies, in which all diminutive polyps can be resected and discarded.

METHODS

We collected data from 2 previous studies that used narrow-band imaging to assess polyps, performed at 5 medical centers (1658 patients with 2285 diminutive polyps; 15 endoscopists). We compared 3 resect and discard strategies: the currently used optical strategy, which relies on high confidence optical assessment of all diminutive polyps; a location-based strategy that classifies all recto-sigmoid diminutive polyps a priori as hyperplastic and all polyps proximal to the recto-sigmoid colon a priori as neoplastic; and a simplified optical strategy, in which all recto-sigmoid diminutive polyps are classified as hyperplastic unless confidently assessed as neoplastic, and all polyps proximal to the recto-sigmoid colon are classified as neoplastic unless confidently assessed as hyperplastic polyps. The primary outcome was the agreement of the surveillance interval calculated for each strategy with the surveillance interval determined by pathology analysis.

RESULTS

The proportion of surveillance intervals that agreed with pathology-based surveillance recommendations was slightly higher when the optical strategy was used compared to the location-based strategy or simplified optical strategy (94% vs 89% and 90%, respectively; P < .001). When the 5-10 year recommendations for patients with low-risk polyps were applied as a 10-year surveillance interval, all 3 strategies resulted in surveillance interval agreement compared to pathology above 90% (the quality benchmark). Use of the simplified or location-based strategy could have avoided pathology analysis for 77% of all polyps, compared to 59% if the optical strategy was used (P < .001). In addition, a higher proportion of patients could receive recommendations immediately after colonoscopy with use of the simplified or location based strategy (65%) compared to the optical strategy (40%) (P < .001).

CONCLUSION

A location-based and a simplified optical resect and discard strategy produced surveillance recommendations that were in agreement with those from pathology analysis for at least 90% of patients, assuming a 10-year surveillance interval for patients with low-risk polyps. These strategies could further reduce the number of pathology examinations and provide more patients with immediate surveillance recommendations. Optical assessment might be reduced or might not be required for resect and discard. Clintrials.gov no: NCT01935180 and NCT01288833.

Procedure Delays and Time of Day Are Not Associated With Reductions in Quality of Screening Colonoscopies

BACKGROUND & AIMS

There have been conflicting results from studies to determine whether factors unrelated to endoscopist skill, such as fatigue, affect the quality of screening colonoscopy. We studied the effects of human and system factors on screening colonoscopy withdrawal time and likelihood of detecting an adenoma in a large cohort of patients.

METHODS

We performed a retrospective analysis of operation and quality improvement data in colonoscopies performed at single academic medical center from November 2012 through February 2014. We collected data from the Northwestern Medicine Enterprise Data Warehouse on endoscopy procedure reports, patient demographics, and pathology reports of all patients undergoing endoscopy. We identified all screening colonoscopies during the study period and determined whether an adenoma was identified in each screening colonoscopy procedure. Our study included data from 7004 screening colonoscopies of patients 50-75 years old performed by endoscopists who performed at least 100 screening colonoscopies during the study period (n = 18).

RESULTS

Approximately 27% of procedures began on time; the median colonoscope insertion time was 5.9 minutes (interquartile range, 4.0-8.6). In multivariable logistic regression analysis adjusting for covariates and endoscopist-level clustering, adenoma detection was not associated with procedure delay (P = .48), hour of day (P = .40), or performing the second of 2 colonoscopy blocks in 1 day (P = .88). Adenoma detection was associated with insertion time overall (P = .006), but there was no consistent directional relationship across insertion quintiles.

CONCLUSIONS

Procedure delays and measured factors associated with fatigue, including time of day and multiple procedure blocks, do not reduce the odds of detecting an adenoma. Adenoma detection varies widely among providers, so efforts to improve adenoma detection should focus mainly on optimizing physician skill.

A greater proportion of liver transplant candidates have colorectal neoplasia than in the healthy screening population

BACKGROUND & AIMS

Various types of liver disease are associated with an increased prevalence of colorectal adenomas. We investigated whether cirrhosis is a risk factor for colorectal neoplasia by analyzing colonoscopy findings from 2 cohorts of patients awaiting liver transplantation.

METHODS

We performed a retrospective analysis to compare findings from colorectal cancer screenings of 567 adult patients with cirrhosis placed on the waitlist for liver transplantation with those from controls (matched for age, sex, body mass index, smoking, and diabetes). Rates of adenoma and advanced adenoma detection were adjusted owing to differences in rates of polypectomies performed in the 2 cohorts.

RESULTS

Adenomas were detected in a significantly higher percentage of patients with cirrhosis (29.3%) than in controls (21.5%) (P = .0057; relative risk [RR], 1.36; 95% confidence interval [CI], 1.09-1.69); and patients with cirrhosis had a higher rate of advanced adenoma detection than controls (13.9% vs 7.7%; P = .0015; relative risk, 1.82; 95% CI, 1.25-2.64). A greater percentage of patients with alcoholic cirrhosis had neoplasias (34.3%) than controls (25.3%; P = .0350; RR, 1.36), and rates of advanced adenoma detection were 16.7% vs 10.2% (P = .0409; RR, 1.63). Adenomas were detected in 27.8% of patients with viral cirrhosis vs 15.9% of controls (P = .0061; RR, 1.74), with rates of advanced adenoma detection of 13.6% vs 5.0% (P = .0041; RR, 2.73). Similar proportions of patients with cirrhosis of other etiologies and controls were found to have colorectal neoplasias.

CONCLUSIONS

Based on a retrospective analysis of colonoscopy findings from patients awaiting liver transplantation, those with alcoholic or viral cirrhosis are at higher risk of developing colorectal neoplasia and should be considered for earlier colonoscopy examination.