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

Predictive values of an immunological fecal occult blood test for the diagnosis of colorectal cancer compared using colonoscopy in symptomatic patients in Yaounde (Cameroon)

INTRODUCTION

The predictive value of immunological fecal occult blood (iFOB) testing for the screening of colorectal cancer has been well described in the Western world. However, its relevance in Sub-Saharan Africa (SSA) is not well evaluated. It could be altered by the other causes of lower gastrointestinal bleeding such as parasitic infections. The aim of this study was to highlight the performance of an iFOB test for the prediction of colorectal cancer (CRC) during colonoscopy in SSA.

METHODOLOGY

We conducted an analytical cross-sectional study in two digestive endoscopic centers of Yaoundé (Cameroon) from the 1st July to the 31 November 2022. Patients presenting with an indication for colonoscopy without any overt gastrointestinal bleeding were included. Sociodemographic and clinical data were collected. All consenting patients underwent a qualitative immunologic occult test through the iFOB test before colonoscopy. Data were analyzed using SPSS version 23.0 software. The performance of the iFOB test for the diagnosis of CRC during colonoscopy was evaluated in terms of sensitivity (Se), specificity (Sp), positive predictive value (PPV) and negative predictive value (NPV).

RESULTS

We included 103 patients during the study period with a male predominance and a sex ratio of 1.7. The median age [IQR] was 52 [38-65] years (range 1 - 84 years). The most common colonoscopic lesions were polyps in 23 patients (22.3%), CRC in 17 patients (16.5%) and hemorrhoids in 15 patients (14.6%). Patients testing positive for iFOB test accounted for 43.7% (45 patients). Among these patients, 31.1% (14 patients) had a CRC. The Se of the occult blood test for CRC detection was calculated to be 82.3% (95%CI: 56.7-96.2); the Sp was 63.9% (95% CI: 53-74); the PPV was 31.1% (95% CI: 24-39) and the NPV was 94.8% (95% CI: 86.6-98.1).

CONCLUSION

The iFOB test has a good NPV, but a poor PPV for the diagnosis of CRC in our study.

Endoscopist adenomas-per-colonoscopy detection rates and risk for postcolonoscopy colorectal cancer: data from the New Hampshire Colonoscopy Registry

BACKGROUND AND AIMS

Adenomas per colonoscopy (APC) may be a better measure of colonoscopy quality than adenoma detection rate (ADR) because it credits endoscopists for each detected adenoma. There are few data examining the association between APC and postcolonoscopy colorectal cancer (PCCRC) incidence. We used data from the New Hampshire Colonoscopy Registry to examine APC and PCCRC risk.

METHODS

We included New Hampshire Colonoscopy Registry patients with an index examination and at least 1 follow-up event, either a colonoscopy or a colorectal cancer (CRC) diagnosis. Our outcome was PCCRC defined as any CRC diagnosed ≥6 months after an index examination. The exposure variable was endoscopist-specific APC quintiles of .25, .40, .50, and .70. Cox regression was used to model the hazard of PCCRC on APC, controlled for age, sex, year of index examination, index findings, bowel preparation, and having more than 1 surveillance examination.

RESULTS

In 32,535 patients, a lower hazard for PCCRC (n = 178) was observed for higher APCs as compared to APCs of <.25 (reference): .25 to <.40: hazard ratio (HR), .35; 95% confidence interval (CI), .22-.56; .40 to <.50: HR, .31; 95% CI, .20-.49; .50 to <.70: HR, .20; 95% CI, .11-.36; and ≥.70: HR, .19; 95% CI, .09-.37. When examining endoscopists with an ADR of at least 25%, an APC of <.50 was associated with a significantly higher hazard than an APC of ≥.50 (HR, 1.65; 95% CI, 1.06-2.56). A large proportion of endoscopists-one-fifth (32 of 152; 21.1%)-had an ADR of ≥25% but an APC of <.50.

CONCLUSIONS

Our novel data demonstrating lower PCCRC risk in examinations performed by endoscopists with higher APCs suggest that APC could be a useful quality measure. Quality improvement programs may identify important deficiencies in endoscopist detection performance by measuring APC for endoscopists with an ADR of ≥25%.

Evaluating false-positive detection in a computer-aided detection system for colonoscopy

BACKGROUND AND AIM

Computer-aided detection (CADe) systems can efficiently detect polyps during colonoscopy. However, false-positive (FP) activation is a major limitation of CADe. We aimed to compare the rate and causes of FP using CADe before and after an update designed to reduce FP.

METHODS

We analyzed CADe-assisted colonoscopy videos recorded between July 2022 and October 2022. The number and causes of FPs and excessive time spent by the endoscopist on FP (ET) were compared pre- and post-update using 1:1 propensity score matching.

RESULTS

During the study period, 191 colonoscopy videos (94 and 97 in the pre- and post-update groups, respectively) were recorded. Propensity score matching resulted in 146 videos (73 in each group). The mean number of FPs and median ET per colonoscopy were significantly lower in the post-update group than those in the pre-update group (4.2 ± 3.7 vs 18.1 ± 11.1; P < 0.001 and 0 vs 16 s; P < 0.001, respectively). Mucosal tags, bubbles, and folds had the strongest association with decreased FP post-update (pre-update vs post-update: 4.3 ± 3.6 vs 0.4 ± 0.8, 0.32 ± 0.70 vs 0.04 ± 0.20, and 8.6 ± 6.7 vs 1.6 ± 1.7, respectively). There was no significant decrease in the true positive rate (post-update vs pre-update: 95.0% vs 99.2%; P = 0.09) or the adenoma detection rate (post-update vs pre-update: 52.1% vs 49.3%; P = 0.87).

CONCLUSIONS

The updated CADe can reduce FP without impairing polyp detection. A reduction in FP may help relieve the burden on endoscopists.

Colon Polyp Surveillance: Separating the Wheat From the Chaff

One goal of colorectal cancer (CRC) screening is to prevent CRC incidence by removing precancerous colonic polyps, which are detected in up to 50% of screening examinations. Yet, the lifetime risk of CRC is 3.9%-4.3%, so it is clear that most of these individuals with polyps would not develop CRC in their lifetime. It is, therefore, a challenge to determine which individuals with polyps will benefit from follow-up, and at what intervals. There is some evidence that individuals with advanced polyps, based on size and histology, benefit from intensive surveillance. However, a large proportion of individuals will have small polyps without advanced histologic features (ie, "nonadvanced"), where the benefits of surveillance are uncertain and controversial. Demand for surveillance will further increase as more polyps are detected due to increased screening uptake, recent United States recommendations to expand screening to younger individuals, and emergence of polyp detection technology. We review the current understanding and clinical implications of the natural history, biology, and outcomes associated with various categories of colon polyps based on size, histology, and number. Our aims are to highlight key knowledge gaps, specifically focusing on certain categories of polyps that may not be associated with future CRC risk, and to provide insights to inform research priorities and potential management strategies. Optimization of CRC prevention programs based on updated knowledge about the future risks associated with various colon polyps is essential to ensure cost-effective screening and surveillance, wise use of resources, and inform efforts to personalize recommendations.

Role of Artificial Intelligence in Colonoscopy Detection of Advanced Neoplasias : A Randomized Trial

BACKGROUND

The role of computer-aided detection in identifying advanced colorectal neoplasia is unknown.

OBJECTIVE

To evaluate the contribution of computer-aided detection to colonoscopic detection of advanced colorectal neoplasias as well as adenomas, serrated polyps, and nonpolypoid and right-sided lesions.

DESIGN

Multicenter, parallel, randomized controlled trial. (ClinicalTrials.gov: NCT04673136).

SETTING

Spanish colorectal cancer screening program.

PARTICIPANTS

3213 persons with a positive fecal immunochemical test.

INTERVENTION

Enrollees were randomly assigned to colonoscopy with or without computer-aided detection.

MEASUREMENTS

Advanced colorectal neoplasia was defined as advanced adenoma and/or advanced serrated polyp.

RESULTS

The 2 comparison groups showed no significant difference in advanced colorectal neoplasia detection rate (34.8% with intervention vs. 34.6% for controls; adjusted risk ratio [aRR], 1.01 [95% CI, 0.92 to 1.10]) or the mean number of advanced colorectal neoplasias detected per colonoscopy (0.54 [SD, 0.95] with intervention vs. 0.52 [SD, 0.95] for controls; adjusted rate ratio, 1.04 [99.9% CI, 0.88 to 1.22]). Adenoma detection rate also did not differ (64.2% with intervention vs. 62.0% for controls; aRR, 1.06 [99.9% CI, 0.91 to 1.23]). Computer-aided detection increased the mean number of nonpolypoid lesions (0.56 [SD, 1.25] vs. 0.47 [SD, 1.18] for controls; adjusted rate ratio, 1.19 [99.9% CI, 1.01 to 1.41]), proximal adenomas (0.94 [SD, 1.62] vs. 0.81 [SD, 1.52] for controls; adjusted rate ratio, 1.17 [99.9% CI, 1.03 to 1.33]), and lesions of 5 mm or smaller (polyps in general and adenomas and serrated lesions in particular) detected per colonoscopy.

LIMITATIONS

The high adenoma detection rate in the control group may limit the generalizability of the findings to endoscopists with low detection rates.

CONCLUSION

Computer-aided detection did not improve colonoscopic identification of advanced colorectal neoplasias.

PRIMARY FUNDING SOURCE

Medtronic.

Long-Term Follow-Up of Colonoscopy Quality Monitoring

INTRODUCTION

High-quality colonoscopy is paramount for colorectal cancer prevention. Since 2009, endoscopists at our institution have received quarterly report cards summarizing individual colonoscopy quality indicators. We have previously shown that implementing this intervention was associated with short-term improvement in adenoma detection rate (ADR). However, the long-term effect of continued monitoring on colonoscopy quality is unclear.

METHODS

We conducted a retrospective study of prospectively administered quarterly colonoscopy quality report cards at the Roudebush Veteran's Affairs Medical Center between April 1, 2012, and August 31, 2019. The anonymized reports included individual endoscopists' ADRs, cecal intubation rates, and withdrawal times. Analyses were performed to determine slopes over time for each quality metric by physician and assess for differences based on whether ADRs were calculated quarterly or yearly.

RESULTS

Data from the report cards of 17 endoscopists who had performed 24,361 colonoscopies were included. The mean quarterly ADR (±SD) was 51.7% (±11.7%) and mean yearly ADR was 47.2% (±13.8%). There was a small increase in overall ADR based on quarterly and yearly measurements (slope + 0.6%, P = 0.02; and slope +2.7%, P < 0.001, respectively), but no significant change in individual ADRs, cecal intubation rates, or withdrawal times. Analysis of SD of ADRs showed no significant difference between yearly and quarterly measurements ( P = 0.064). Individual endoscopists' ADR SD differences between yearly and quarterly measurements ranged from -4.7% to +6.8%.

DISCUSSION

Long-term colonoscopy quality monitoring paralleled stable improvements in overall ADR. For endoscopists with baseline high ADR, frequent monitoring and reporting of colonoscopy quality metrics may not be necessary.

Association of polymorphisms of calcium reabsorption genes SLC12A1, KCNJ1 and SLC8A1 with colorectal adenoma

BACKGROUND

In recent years, morbidity and mortality from colorectal cancer have increased. Colorectal adenoma is the main precancerous lesion. Understanding the pathogenesis of colorectal adenoma will help to improve the early diagnosis rate of colorectal cancer.

METHODS

In this case-control study, we focused on three single nucleotide polymorphisms (SNPs) in genes SLC8A1 (rs4952490), KCNJ1 (rs2855798), and SLC12A1 (rs1531916). We analyzed 207 colorectal adenoma patients (112 high-risk cases and 95 low-risk cases) and 212 control subjects by Sanger sequencing. A food frequency questionnaire (FFQ) was used to survey demographic characteristics and dietary nutrition.

RESULTS

In the overall analysis, the results suggested that the AA+AG and AG genotype carriers of rs4952490 had a 73.1% and 78% lower risk of colorectal adenoma compared to GG genotype carriers, respectively. However rs2855798 and rs1531916 were not associated with the incidence of colorectal adenoma. Additionally, stratified analysis showed that rs4952490 AA+AG and AG genotypes had a protective effect against low-risk colorectal adenoma in patients aged ≤ 60 years old who were non-smokers. We also observed that when calcium intake was higher than 616 mg/d and patients carried at least one gene with variant alleles there was a protective effect against low-risk colorectal adenoma.

CONCLUSIONS

Interactions between dietary calcium intake and calcium reabsorption genes may affect the occurrence and development of colorectal adenoma.

Polyp detection rate and cumulative incidence of post-colonoscopy colorectal cancer in Germany

Studies have shown that the quality of colonoscopy influences the incidence of post-colonoscopy colorectal cancer (PCCRC). However, data from Germany on this association are lacking. We aimed to assess cumulative incidence of PCCRC in persons undergoing colonoscopy in Germany according to the physician's polyp detection rate (PDR). Using the German Pharmacoepidemiological Research Database (GePaRD) with claims data of ~20% of the German population, we included persons with a baseline colonoscopy between 2008 and 2017 and categorized them according to the procedure at baseline (snare polypectomy, forceps polypectomy, no polypectomy). In each subgroup, we distinguished between persons examined by physicians with a PDR in the lowest quartile vs higher quartiles and described cumulative CRC incidence during follow-up. Overall, 822 715 persons examined by 1752 physicians were included. One quarter of the physicians had a PDR ≤21.8% (lowest quartile). In all subgroups, the 5-year cumulative CRC incidence was statistically significantly higher in persons examined by physicians with a PDR ≤21.8% vs >21.8%: It was 69% higher in persons with snare polypectomy (0.88% vs 0.52%), 87% higher in persons with forceps polypectomy (0.58% vs 0.31%), and 48% higher in persons without polypectomy at baseline (0.31% vs 0.21%). In conclusion, we found a substantially increased PCCRC risk in persons examined by physicians with a low PDR in Germany, irrespective of the baseline findings. Our study highlights the importance of a high-quality colonoscopy to maximize the preventive effect of colonoscopy on CRC incidence.

Artificial Intelligence-Assisted Colonoscopy for Colorectal Cancer Screening: A Multicenter Randomized Controlled Trial

BACKGROUND AND AIMS

Artificial intelligence (AI)-assisted colonoscopy improves polyp detection and characterization in colonoscopy. However, data from large-scale multicenter randomized controlled trials (RCT) in an asymptomatic population are lacking.

METHODS

This multicenter RCT aimed to compare AI-assisted colonoscopy with conventional colonoscopy for adenoma detection in an asymptomatic population. Asymptomatic subjects 45-75 years of age undergoing colorectal cancer screening by direct colonoscopy or fecal immunochemical test were recruited in 6 referral centers in Hong Kong, Jilin, Inner Mongolia, Xiamen, and Beijing. In the AI-assisted colonoscopy, an AI polyp detection system (Eagle-Eye) with real-time notification on the same monitor of the endoscopy system was used. The primary outcome was overall adenoma detection rate (ADR). Secondary outcomes were mean number of adenomas per colonoscopy, ADR according to endoscopist's experience, and colonoscopy withdrawal time. This study received Institutional Review Board approval (CRE-2019.393).

RESULTS

From November 2019 to August 2021, 3059 subjects were randomized to AI-assisted colonoscopy (n = 1519) and conventional colonoscopy (n = 1540). Baseline characteristics and bowel preparation quality between the 2 groups were similar. The overall ADR (39.9% vs 32.4%; P < .001), advanced ADR (6.6% vs 4.9%; P = .041), ADR of expert (42.3% vs 32.8%; P < .001) and nonexpert endoscopists (37.5% vs 32.1%; P = .023), and adenomas per colonoscopy (0.59 ± 0.97 vs 0.45 ± 0.81; P < .001) were all significantly higher in the AI-assisted colonoscopy. The median withdrawal time (8.3 minutes vs 7.8 minutes; P = .004) was slightly longer in the AI-assisted colonoscopy group.

CONCLUSIONS

In this multicenter RCT in asymptomatic patients, AI-assisted colonoscopy improved overall ADR, advanced ADR, and ADR of both expert and nonexpert attending endoscopists. (ClinicalTrials.gov, Number: NCT04422548).

At What Age Should We Stop Colorectal Cancer Screening? When Is Enough, Enough?

There is strong evidence that colorectal cancer screening can reduce both colorectal cancer incidence and mortality. Guidelines recommend screening for individuals age 45 to 75 years, but are less certain about the benefits after age 75 years. Dalmat and colleagues provide evidence that individuals with a prior negative colonoscopy 10 years or more prior to reaching age 76 to 85 years, had a low risk of colorectal cancer, and would be less likely to benefit from further screening. It is important to note that this study population did not include individuals with a family history of colon cancer or a personal history of having high-risk adenomas. These data suggest that a negative colonoscopy can be an effective risk-stratification tool when discussing further screening with elderly patients. See related article by Dalmat et al., p. 37.

Adenoma Detection Rate and Clinical Characteristics Influence Advanced Neoplasia Risk After Colorectal Polypectomy

BACKGROUND AND AIMS

Postpolypectomy risk stratification for subsequent metachronous advanced neoplasia (MAN) is imprecise and does not account for colonoscopist adenoma detection rate (ADR). Our aim was to assess association of ADR with MAN and create a prediction model for postpolypectomy risk stratification incorporating ADR and other factors.

METHODS

We conducted a retrospective cohort study of individuals with baseline polypectomy and subsequent surveillance colonoscopy from 2004 to 2016 within the U.S. Department of Veterans Affairs (VA). Clinical factors, polyp findings, and baseline colonoscopist ADR were considered for the model. Model performance (sensitivity, specificity, and area under the curve) for identifying individuals with MAN was compared with 2020 U.S. Multi-Society Task Force on Colorectal Cancer (USMSTF) surveillance recommendations.

RESULTS

A total of 30,897 individuals were randomly assigned 2:1 into independent model training and validation sets. Increasing age, male sex, diabetes, current smoking, adenoma number, polyp location, adenoma ≥10 mm or with tubulovillous/villous features, and decreasing colonoscopist ADR were independently associated with MAN. A range of 1.48- to 1.66-fold increased risk for MAN was observed for ADR in the lowest 3 quintiles (ADR <19.7%-39.3%) vs the highest quintile (ADR >47.0%). When the final model selected based on the training set was applied to the validation set, improved sensitivity and specificity over 2020 USMSTF risk stratification were achieved (P = .001), with an area under the curve of 0.62 (95% confidence interval, 0.60-0.64).

CONCLUSIONS

Colonoscopist ADR is associated with MAN. Combining clinical factors and ADR for risk stratification has potential to improve postpolypectomy risk stratification. Improving ADR is likely to improve postpolypectomy outcomes.

Survey on Mental Health Status and Quality of Life and Correlation among Patients with Permanent Stoma of Colorectal Tumor

Background

Colorectal cancer is one of the malignant tumors of the digestive system relatively hidden onset with unobvious early clinical symptoms. Most patients have developed into middle and late stages when they were diagnosed, missing the best period of operation. Advanced colorectal cancer has strong diffusion and metastasis with short survival time, which seriously threatens the life safety of patients.

Objective

To investigate the mental health status and quality of life and the relationship between them in patients with permanent stoma of colorectal cancer.

Methods

In this study, a case-control study was conducted to select 80 patients (stoma group) with colorectal cancer treated by permanent stoma surgery in our hospital from January 2020 to June 2021 and 80 patients (control group) with colorectal cancer treated by sphincter-preserving surgery at the same time. The psychological health degree and quality of life of the two groups of patients were evaluated by the psychological resilience scale (CD-RISC), the positive psychological capital questionnaire (PPQ), and the cancer patient quality of life-specific scale (QOL-LC), and a linear correlation model was used to analyze the correlation of CD-RISC score, PPQ score, and QOL-LC score.

Results

The total scores of tenacity, optimism, self-improvement, and resilience of the patients in the stoma group were significantly lower than those in the control one, and the difference between them was statistically significant (P < 0.05); the four dimensions of self-efficacy, optimism, hope, and resilience and the total score of PPQ of patients in the stoma group were significantly lower than those in the control group, and all of the differences were statistically significant (P < 0.05); the somatic function, psychological function, symptoms of side effects, social function, and the total QOL-LC score of patients in the stoma one were significantly lower than those in the control one, and all of the differences were statistically significant (P < 0.05); the total QOL-LC score of patients in the stoma group showed a significant positive correlation with PPQ score and CD-RISC score (r = 0.511 and r = 0.608, P < 0.01).

Conclusion

The overall level of mental health and life quality of patients with permanent stoma of colorectal cancer was worse than that of patients without stoma measures, and there was a certain correlation between patients' mental health and quality of life.

Key factors for improving adenoma detection rate

INTRODUCTION

Colonoscopy is a fundamental tool in colorectal cancer (CRC) prevention. Nevertheless, one-fourth of colorectal neoplasms are still missed during colonoscopy, potentially being the main reason for post-colonoscopy colorectal cancer (PCCRC). Adenoma detection rate (ADR) is currently known as the best quality indicator correlating with PCCRC incidence.

AREAS COVERED

We performed a literature review in order to summarize evidences investigating key factors affecting ADR: endoscopists education and training, patient management, endoscopic techniques, improved navigation (exposition defect), and enhanced lesions recognition (vision defect) were considered.

EXPERT OPINION

'Traditional' factors, such as split dose bowel preparation, adequate withdrawal time, and right colon second view, held a significant impact on ADR. Several devices and technologies have been developed to promote high-quality colonoscopy, however artificial intelligence may be considered the most promising tool for ADR improvement, provided that endoscopists education and recording are guaranteed.

Clinically significant serrated polyp detection rates and risk for postcolonoscopy colorectal cancer: data from the New Hampshire Colonoscopy Registry

BACKGROUND AND AIMS

Higher adenoma detection rates reduce the risk of postcolonoscopy colorectal cancer (PCCRC). Clinically significant serrated polyps (CSSPs; defined as any sessile serrated polyp, traditional serrated adenoma, large [≥1 cm] or proximal hyperplastic polyp >5 mm) also lead to PCCRC, but there are no data on associated CSSP detection rates (CSSDRs). We used data from the New Hampshire Colonoscopy Registry (NHCR) to investigate the association between PCCRC risk and endoscopist CSSDR.

METHODS

We included NHCR patients with 1 or more follow-up events: either a colonoscopy or a colorectal cancer (CRC) diagnosis identified through linkage with the New Hampshire State Cancer Registry. We defined our outcome, PCCRC, in 3 time periods: CRC diagnosed 6 to 36 months, 6 to 60 months, or all examinations (6 months or longer) after an index examination. We excluded patients with CRC diagnosed at or within 6 months of the index examination, with incomplete examinations, or with inflammatory bowel disease. The exposure variable was endoscopist CSSDR at the index colonoscopy. Cox regression was used to model the hazard of PCCRC on CSSDR controlling for age, sex, index findings, year of examination, personal history of colorectal neoplasia, and having more than 1 surveillance examination.

RESULTS

One hundred twenty-eight patients with CRC diagnosed at least 6 months after their index examination were included. Our cohort included 142 endoscopists (92 gastroenterologists). We observed that the risk for PCCRC 6 months or longer after the index examination was significantly lower for examinations performed by endoscopists with CSSDRs of 3% to <9% (hazard ratio [HR], .57; 95% confidence interval [CI], .39-.83) or 9% or higher (HR, .39; 95% CI, .20-.78) relative to those with CSSDRs under 3%.

CONCLUSIONS

Our study is the first to demonstrate a lower PCCRC risk after examinations performed by endoscopists with higher CSSDRs. Both CSSDRs of 9% and 3% to <9% had statistically lower risk of PCCRC than CSSDRs of <3%. These data validate CSSDR as a clinically relevant quality measure for endoscopists.

Implications of stable or increasing adenoma detection rate on the need for continuous measurement

BACKGROUND AND AIMS

Measurement of the adenoma detection rate (ADR) is resource intensive, and the benefit of continuous measurement for colonoscopists with high ADR is unclear. We examined the ADR trends at our center to determine whether continuous measurement for consistently high ADR is warranted.

METHODS

Among colonoscopies performed between January 1999 and November 2019 at a tertiary center, we analyzed data from colonoscopists performing at least 50 screening colonoscopies annually for 5 consecutive years. ADR trends for individual colonoscopists were examined using Joinpoint regression models.

RESULTS

Eleven colonoscopists performed screening colonoscopies on 14,047 patients, and 5912 among them had at least 1 conventional adenoma removed (42.0%). Of 25,829 polyps, 13,585 (52.6%) were conventional adenomas or adenocarcinomas and contributed to ADR calculation. All but 1 colonoscopist included met the recommended minimum threshold ADR of 25% continuously over the study period. Of the 11 colonoscopists, 5 had an increase in their ADR and the remaining 6 had stable ADRs over the study period.

CONCLUSIONS

For colonoscopists consistently performing above the minimum threshold, diversion of resources toward improvement of quality measures other than ADR is justified.

Post-polypectomy colonoscopy surveillance: Can we improve the diagnostic yield?

Although adenomas and serrated polyps are the preneoplastic lesions of colorectal cancer, only few of them will eventually progress to cancer. This review provides a comprehensive overview of the present and future of post-polypectomy colonoscopy surveillance. Post-polypectomy surveillance guidelines have recently been updated and all share the aim towards more selective and less frequent surveillance. We have examined these current guidelines and compared the recommendations of each of them. To improve the diagnostic yield of post-polypectomy surveillance it is important to find predictors of metachronous polyps that better identify high-risk individuals of developing advanced neoplasia. For this reason, we have also conducted a literature review of the molecular biomarkers of metachronous advanced colorectal polyps. Finally, we have discussed future directions of post-polypectomy surveillance and identified possible strategies to improve the use of endoscopic resources with the COVID-19 pandemic.

Faecal immunochemical test outside colorectal cancer screening?

Faecal immunochemical tests (FITs) are the most widely colorectal cancer (CRC) diagnostic biomarker available. Many population screening programmes are based on this biomarker, with the goal of reducing CRC mortality. Moreover, in recent years, a large amount of evidence has been produced on the use of FIT to detect CRC in patients with abdominal symptoms in primary healthcare as well as in surveillance after adenoma resection. The aim of this review is to highlight the available evidence on these two topics. We will summarize the evidence on diagnostic yield in symptomatic patients with CRC and significant colonic lesion and the different options to use this (thresholds, brands, number of determinations, prediction models and combinations). We will include recommendations on FIT strategies in primary healthcare proposed by regulatory bodies and scientific societies and their potential effects on healthcare resources and CRC prognosis. Finally, we will show information regarding FIT-based surveillance as an alternative to endoscopic surveillance after high-risk polyp resection. To conclude, due to the coronavirus disease 2019 pandemic, FIT-based strategies have become extremely relevant since they enable a reduction of colonoscopy demand and access to the healthcare system by selecting individuals with the highest risk of CRC.

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.

Polyprev: Randomized, Multicenter, Controlled Trial Comparing Fecal Immunochemical Test with Endoscopic Surveillance after Advanced Adenoma Resection in Colorectal Cancer Screening Programs: A Study Protocol

Colorectal cancer (CRC) screening programs have been implemented to reduce the burden of the disease. When an advanced colonic lesion is detected, clinical practice guidelines recommend endoscopic surveillance with different intervals between explorations. Endoscopic surveillance is producing a considerable increase in the number of colonoscopies, with a limited effect on the CRC incidence. Instead, participation in CRC screening programs based on the fecal immunochemical test (FIT) could be a non-inferior alternative to endoscopic surveillance to reduce 10-year CRC incidence. Based on this hypothesis, we have designed a multicenter and randomized clinical trial within the Spanish population CRC screening programs to compare FIT surveillance with endoscopic surveillance. We will include individuals aged from 50 to 65 years with complete colonoscopy and advanced lesions resected within the CRC screening programs. Patients will be randomly allocated to perform an annual FIT and colonoscopy if fecal hemoglobin concentration is ≥10 µg/g, or to perform endoscopic surveillance. On the basis of the non-superior CRC incidence, we will recruit 1894 patients in each arm. The main endpoint is 10-year CRC incidence and the secondary endpoints are diagnostic yield, participation, adverse effects, mortality and cost-effectiveness. Our results may modify the clinical practice after advanced colonic resection in CRC screening programs.