Age-Stratified Prevalence and Predictors of Neoplasia Among U.S. Adults Undergoing Screening Colonoscopy in a National Endoscopy Registry

Comparative Effectiveness and Cost-Effectiveness of Colorectal Cancer Screening With Blood-Based Biomarkers (Liquid Biopsy) vs Fecal Tests or Colonoscopy

BACKGROUND & AIMS

Colorectal cancer (CRC) screening is highly effective but underused. Blood-based biomarkers (liquid biopsy) could improve screening participation.

METHODS

Using our established Markov model, screening every 3 years with a blood-based test that meets minimum Centers for Medicare & Medicaid Services' thresholds (CMSmin) (CRC sensitivity 74%, specificity 90%) was compared with established alternatives. Test attributes were varied in sensitivity analyses.

RESULTS

CMSmin reduced CRC incidence by 40% and CRC mortality by 52% vs no screening. These reductions were less profound than the 68%-79% and 73%-81%, respectively, achieved with multi-target stool DNA (Cologuard; Exact Sciences) every 3 years, annual fecal immunochemical testing (FIT), or colonoscopy every 10 years. Assuming the same cost as multi-target stool DNA, CMSmin cost $28,500/quality-adjusted life-year gained vs no screening, but FIT, colonoscopy, and multi-target stool DNA were less costly and more effective. CMSmin would match FIT's clinical outcomes if it achieved 1.4- to 1.8-fold FIT's participation rate. Advanced precancerous lesion (APL) sensitivity was a key determinant of a test's effectiveness. A paradigm-changing blood-based test (sensitivity >90% for CRC and 80% for APL; 90% specificity; cost ≤$120-$140) would be cost-effective vs FIT at comparable participation.

CONCLUSIONS

CMSmin could contribute to CRC control by achieving screening in those who will not use established methods. Substituting blood-based testing for established effective CRC screening methods will require higher CRC and APL sensitivities that deliver programmatic benefits matching those of FIT. High APL sensitivity, which can result in CRC prevention, should be a top priority for screening test developers. APL detection should not be penalized by a definition of test specificity that focuses on CRC only.

Diagnostic yield from symptomatic lower gastrointestinal endoscopy in the UK: A British Society of Gastroenterology analysis using data from the National Endoscopy Database

BACKGROUND

The value of lower gastrointestinal endoscopy (LGIE; colonoscopy or sigmoidoscopy) relates to its ability to detect clinically relevant findings, predominantly cancers, preneoplastic polyps or inflammatory bowel disease. There are concerns that many LGIEs are performed on low-risk patients with limited benefit.

AIMS

To determine the diagnostic outcomes of LGIE for common symptoms.

METHODS

We performed a cross-sectional study of diagnostic LGIE between March 2019 and February 2020 using the UK National Endoscopy Database. We used mixed-effects logistic regression models, incorporating random (endoscopist) and fixed (symptoms, patient age, and sex) effects upon two dependent variables (large polyp [≥10 mm] and cancer diagnosis). Adjusted positive predictive values (aPPVs) were calculated.

RESULTS

We analysed 384,510 LGIEs; 33.2% were performed on patients aged under 50 and 53.6% on women. Regarding colonoscopies, the unadjusted PPV for cancer was 1.5% (95% CI: 1.4-1.5); higher for men than women (1.9% vs. 1.1%, p < 0.01). The PPV for large polyps was 3.2% (95% CI: 3.1-3.2). The highest colonoscopy cancer aPPVs were in the over 50s (1.9%) and in those with rectal bleeding (2.5%) or anaemia (2.1%). Cancer aPPVs for other symptoms were <1% despite representing 54.3% of activity. In patients under 50, aPPVs were 0.4% for cancer and 1.6% for large polyps. Results were similar for sigmoidoscopy.

CONCLUSIONS

Most colonoscopies were performed on patients with low-risk symptoms, where cancer risk was similar to the general population. Cancer and large polyp yield was highest in elderly patients with rectal bleeding or anaemia, although still fell short of FIT-based screening yields.

Follow-Up Colonoscopy for Detection of Missed Colorectal Cancer After Diverticulitis

BACKGROUND & AIMS

Colonoscopy often is recommended after an episode of diverticulitis to exclude missed colorectal cancer (CRC). This is a controversial recommendation based on limited evidence. We estimated the prevalence and odds of CRC and advanced colorectal neoplasia on colonoscopy in patients with diverticulitis compared with CRC screening.

METHODS

Using data from the Gastrointestinal Quality Improvement Consortium registry, we performed a cross-sectional study with patients ≥40 years old undergoing outpatient colonoscopy for an indication of diverticulitis follow-up evaluation or CRC screening. The primary outcome was CRC. The secondary outcome was advanced colorectal neoplasia. Odds ratios (ORs) and 95% CIs were calculated.

RESULTS

We identified 4,591,921 outpatient colonoscopies performed for screening and 91,993 colonoscopies for diverticulitis follow-up evaluation. CRC prevalence was 0.33% in colonoscopies for screening and 0.31% in colonoscopies for diverticulitis. Compared with screening, patients with diverticulitis were less likely to have CRC (adjusted OR, 0.84; 95% CI, 0.74-0.94). CRC prevalence decreased to 0.17% in colonoscopies performed for diverticulitis only. Compared with screening, patients with diverticulitis as the only indication were less likely to have CRC (adjusted OR, 0.49; 95% CI, 0.36-0.68). CRC prevalence increased to 1.43% in patients with complicated diverticulitis. Compared with screening, patients with complicated diverticulitis were more likely to have CRC (adjusted OR, 3.57; 95% CI, 1.59-8.01).

CONCLUSIONS

The risk of CRC cancer is low in most patients with diverticulitis. Patients with complicated diverticulitis are the exception. Our results suggest that colonoscopy to detect missed CRC should include diverticulitis patients with a complication and those not current with CRC screening.

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).

Esophagogastroscopic Abnormalities Potentially Guided Patients Younger than 50 Years Old to Undergo Colonoscopy Earlier: A Retrospective Cross-Sectional Study

BACKGROUND

The incidence of early-onset colorectal cancer (CRC) is continuously increasing worldwide. Current guidelines in China recommend average-risk individuals starting CRC screening at age 50.

AIMS

To investigate the relationship between the gastric histopathology and colorectal neoplasms to identify CRC risk factors which potentially guide earlier colonoscopy in individuals aged < 50 years.

METHODS

A retrospective cross-sectional study was conducted on 8819 patients younger than age 50 who underwent gastroscopy and colonoscopy simultaneously between November 7, 2020 and November 14, 2022. Multivariate logistic regression was used to evaluate whether various gastric histopathology are risk factors for different types of colorectal polyps, reporting odds ratios (ORs) with corresponding 95% confidence intervals (CIs).

RESULTS

A total of 3390 cases (38.44%) under 50 years old were diagnosed as colorectal polyps. Advanced age (OR 1.66, 95%CI 1.57-1.76), male sex (OR 2.67, 95%CI 2.33-3.08), Helicobacter pylori (H. pylori) infection (OR 1.43, 95%CI 1.24-1.65), gastric polyps (OR 1.29, 95%CI 1.10-1.52), and low-grade intraepithelial neoplasia (LGIN) (OR 2.52, 95%CI 1.39-4.57) were independent risk factors for colorectal adenomas. For non-adenomatous polyps, reflux esophagitis (OR 1.38, 95%CI 1.11-1.71) was also an independent risk factor. Besides, older age (OR 1.90, 95%CI 1.66-2.18), male sex (OR 2.15, 95%CI 1.60-2.87), and H. pylori infection (OR 1.67, 95%CI 1.24-2.24) were associated with a higher risk of advanced neoplasms (advanced adenoma and CRC).

CONCLUSIONS

Earlier colonoscopy for identification and screening may need to be considered for individuals younger than 50 years old with H. pylori infection, LGIN, gastric polyps, and reflux esophagitis. Risk-adapted CRC screening initiation age allows a personalized and precise screening.

Association of clinical characteristics and recurrence of conventional colorectal adenomas with patient age: a single-center study

OBJECTIVES

We performed a clinical study comparing early-onset and late-onset conventional colorectal adenomas (CCRAs) since little is known about the differences in their characteristics.

METHODS

Pearson's chi-square test and the Kruskal‒Wallis test were used to compare basic information. MCAR tests and multiple imputation were performed to complete missing values. Multivariate logistic analysis and propensity score matching were used to identify the risk factors for recurrence.

RESULTS

We included 2793 patients (688 with early-onset CCRAs and 2105 with late-onset CCRAs) from January 2017 to December 2021. Patients with early-onset CCRAs had higher levels of Hb, ALB, and triglycerides but lower HDL levels and N/L ratios. Moreover, we found that more early-onset CCRAs were in the left colon than late-onset CCRAs, and the size of early-onset CCRAs was larger. Early-onset CCRAs tended to lack pedicles compared to late-onset CCRAs. Additionally, the ratio of EMR and APC in early-onset CCRAs was higher than that in late-onset CCRAs, and the ratio of ESD and surgery for late-onset CCRAs was higher. We found that age ≥ 50 years, abnormal vessels, drinking alcohol, and DB and ALB levels may be risk factors for recurrence, while the LDL level may be a protective factor. Finally, analysis of cumulative recurrence rates after PSM showed that patients with late-onset CCRAs exhibited higher recurrence rates (P < 0.05).

CONCLUSION

Compared with late-onset CCRAs, early-onset CCRAs were associated with higher triglyceride levels, lower HDL levels, and larger tumor volumes. Age ≥ 50 years, abnormal vessels, alcohol consumption, and DB and ALB levels were independent risk factors for recurrence of CCRAs.

Adenoma Detection Rate Benchmarks: An Updated Analysis

Early-onset colorectal cancer prompted organizations to reduce the recommended screening initiation age from 50 to 45 years. The American Society for Gastrointestinal Endoscopy Quality Assurance in Endoscopy Committee recommends 3 priority quality indicators for colonoscopy services. The adenoma detection rate is considered the most important measure with the established benchmark based upon studies of patients 50 years or older. The incidence of polyps increases with age, so this change has an as-yet-unknown effect on the new benchmark. Five studies were reviewed. Based upon the results, 45- to 50-year-old patients should be included in facilities' adenoma detection rate calculations using the currently recommended benchmarks of 25% for women and men combined, or 20% for women and 30% for men when the genders are calculated separately. Males consistently had more adenomas than females in each of the 3 studies that separated genders, a detail that might merit gender-based adenoma detection rate determinations in some practices. One study indicated caution is advised; it recommends males and females be calculated separately and different benchmarks be used for each gender. The adenoma detection rate has been shown to increase over time. More studies are needed to guide screening quality metrics.

Synchronous Neoplasia Rates at Colonoscopic Diagnosis of Early-Onset vs Average-Onset Colorectal Cancer

Importance

The incidence of early-onset colorectal cancer (CRC) (age, <50 years) continues to increase globally within high-income countries.

Objective

To examine and compare rates of synchronous neoplasia found in patients at colonoscopic diagnosis of early-onset CRC with rates found at diagnosis of average-onset CRC.

Design, Setting, and Participants

In this multisite retrospective and cross-sectional study conducted at Mayo Clinic sites and in the Mayo Clinic Health System from January 1, 2012, to December 31, 2022, 150 randomly selected patients with early-onset CRC were identified from the electronic health record and matched with 150 patients with average-onset CRC based on sex and colonoscopic indication. Patients with known hereditary syndromes, past history of CRC, or inflammatory bowel disease were excluded.

Main Outcomes and Measures

Colonoscopic findings (polyp size, number, site) and related histopathologic findings (adenoma, advanced adenoma, sessile serrated polyp) were analyzed in association with cancer clinicopathologic features and molecular data (mismatch repair status, KRAS, and BRAFV600E).

Results

Among 300 patients (156 men [52%]), the median age at diagnosis was 43 years (IQR, 39-47 years) for those with early-onset CRC and 67 years (IQR, 57-76) for those with average-onset CRC. Overall, 85% of patients were symptomatic at CRC diagnosis. Cancer stage, grade, molecular features, body mass index, and family history did not differ significantly between these groups. Among patients with colon cancer, the overall prevalence of synchronous neoplasia was similar, yet advanced adenomas were 3 times more frequent in those with early-onset vs average-onset cancers (31 of 75 [41%] vs 10 of 75 [13%]; P < .001). This difference was not associated with cancer stage or primary location. Among patients with rectal cancer, nonadvanced adenomas were less frequent among the early-onset group than the average-onset group (21 of 75 [28%] vs 36 of 75 [48%]), and although the prevalence of advanced adenomas was similar (11 of 75 [15%] vs 14 of 75 [19%]), they were more commonly located in the rectum (early onset, 5 of 11 [45%] vs average onset, 1 of 14 [7%]). Patients with early-onset cancer of the colon were significantly more likely than those with early-onset cancer of the rectum to have a synchronous advanced adenoma (31 of 75 [41%] vs 11 of 75 [15%]; P < .001).

Conclusions and Relevance

In this cross-sectional study, synchronous advanced adenomas were more commonly found in patients with early-onset colon cancer compared with average-onset colon cancer, and they were distributed throughout the colon. In contrast, advanced adenomas were not increased in patients with rectal cancer and, when detected, were predominantly located in the rectum.

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.

Key quality indicators in colonoscopy

Many quality indicators have been proposed for colonoscopy, but most colonoscopists and endoscopy groups focus on measuring the adenoma detection rate and the cecal intubation rate. Use of proper screening and surveillance intervals is another accepted key indicator but it is seldom evaluated in clinical practice. Bowel preparation efficacy and polyp resection skills are areas that are emerging as potential key or priority indicators. This review summarizes and provides an update on key performance indicators for colonoscopy quality.