Risk of perforation after colonoscopy and sigmoidoscopy: a population-based study

CT Colonography versus Multitarget Stool DNA Test for Colorectal Cancer Screening: A Cost-Effectiveness Analysis

Background Colorectal cancer (CRC) is largely preventable or curable with effective screening. Purpose To compare both the clinical efficacy and cost effectiveness of CRC screening with CT colonography (CTC) with those of multitarget stool DNA (mt-sDNA) testing. Materials and Methods A state-transition Markov model was constructed using updated natural history evidence for colorectal polyps applied to a hypothetical 10 000-person cohort representative of the 45-year-old U.S. population. Three screening strategies were modeled with these data: mt-sDNA testing every 3 years, the conventional CTC (CTCconv) strategy of immediate polypectomy for all polyps measuring at least 6 mm every 5 years, and the surveillance CTC (CTCsurv) strategy of 3-year CTC follow-up for small polyps (6-9 mm) and polypectomy for large polyps (≥10 mm). Multifaceted model validation was performed to confirm robustness. A detailed sensitivity analysis was performed in addition to the base-case scenario. Results Without screening, the cumulative incidence of CRC was 7.5% (n = 752), which was reduced by 59% (n = 310) with mt-sDNA, 75% (n = 190) with CTCconv, and 70% (n = 223) with CTCsurv screening. The estimated programmatic costs per person for no screening, mt-sDNA, CTCconv, and CTCsurv were $4955, $6011, $4422, and $3913, respectively. The estimated cost per quality-adjusted life year (QALY) gained for mt-sDNA testing was $8878, whereas both CTC strategies resulted in cost savings. Accordingly, CTC strategies dominated over both mt-sDNA and no screening (ie, more clinically efficacious and more cost-effective [cost-saving]). However, the CTCconv strategy was not as cost-effective as the CTCsurv strategy, as costs related to more optical colonoscopies did not offset the corresponding small gains in QALYs. The results were similar when CRC screening began at 50 and 65 years of age. Conclusion Both CTC screening strategies dominated over mt-sDNA screening and no screening, yielding cost savings and increased clinical efficacy. The CTC strategy consisting of 3-year surveillance for small colorectal polyps and colonoscopy referral for large polyps achieved the best overall balance of cost and clinical efficacy. © RSNA, 2025 Supplemental material is available for this article. See also the editorial by Galgano and Smith in this issue.

The causes, and impact, of colonoscopic perforation for endoscopists: lessons from a qualitative interview study

INTRODUCTION

Safety and the avoidance of adverse events are crucial in patient care. A number of explanatory variables for the serious adverse event of colonoscopic perforation have been identified; however, the context in which perforation occurs has largely been overlooked, as too has the subsequent impact on the colonoscopist. This study examined the human and environmental factors associated with colonoscopic perforations, along with colonoscopists' reactions to these, with a view to informing strategies for safer practice and clinician support.

METHODS

This qualitative study explored the experiences of colonoscopists who reported a previous colonoscopic perforation. Semi-structured interviews were undertaken with 11 colonoscopists, recruited through professional networks. Interviews were recorded and transcribed and analysed using a framework approach.

RESULTS

Human and environmental factors contributing to perforation included colonoscopist fatigue, time pressure and equipment failure. Four distinct stages were identified in colonoscopists' reactions to perforation: ' The Perforation Realisation ' comprising a range of strong and powerful emotions; ' The Consequences ' involving feelings of personal responsibility, self-blame, fear of repercussion and vulnerability; ' Acceptance and Refocus ' comprising a period of coming to terms with the perforation; and finally ' Reflection and Learning ' where the colonoscopist reflected on the case and applied learning to their future practice.

CONCLUSION

This study examines colonoscopists' personal experiences of perforations. It identifies the stages that colonoscopists experience after causing a perforation, and some of the broader contextual factors that can lead to these potentially preventable adverse events. The data suggest the need for greater emotional and pastoral support for endoscopists when such events occur.

Association between colonoscopy and colorectal cancer occurrence and mortality in the older population: a population-based cohort study

We aimed to evaluate the association between colonoscopy and colorectal cancer (CRC) occurrence and related mortality in an older population.This retrospective, nationwide, population-based cohort study used data of adults aged ≥40 years from the Health Insurance Review and Assessment Service database. After excluding colonoscopy within 6 months of CRC diagnosis during enrollment, CRC occurrence and related mortality were compared between colonoscopy and non-colonoscopy groups using a time-dependent Cox proportional hazard model. Subgroup analysis was conducted among four age groups: young, middle-aged, old, and very old.Among 748986 individuals followed for 9.64 (SD 0.99) years, the colonoscopy group had a 65% lower CRC occurrence (adjusted hazard ratio [HRa] 0.35, 95%CI 0.32-0.38) and 76% lower CRC-related mortality (HRa 0.24, 95%CI 0.18-0.31) after 5 years compared with the non-colonoscopy group. Colonoscopy was associated with the most significant reduction in CRC occurrence in the middle-aged group (HRa 0.32, 95%CI 0.29-0.35) and in CRC-related mortality in the young group (HRa 0.04, 95%CI 0.01-0.33); the very old group had the least reduction in both CRC occurrence and CRC-related mortality (HRa 0.44, 95%CI 0.33-0.59 and HRa 0.28, 95%CI 0.15-0.53, respectively).We found a significant association between colonoscopy and reduction in CRC occurrence and CRC-related mortality in adults aged ≥40 years after 5 years of follow-up; however, these associations were weaker in the very old group. More research is needed on the association between colonoscopy and older age.

Endoscopic management of colonic perforations

PURPOSE OF REVIEW

We will review the current management of colonic perforations, with particular emphasis on iatrogenic perforations caused by colonoscopy, the leading etiology. We will focus on recently developed endoscopic techniques and technologies that obviate morbid emergency surgery (the standard management approach in years past).

RECENT FINDINGS

Colonic perforations are rare but potentially fatal complications of both diagnostic and therapeutic colonoscopy resulting in death in approximately 5% of cases with the mortality increasing with delay in diagnosis and treatment. As novel endoscopic techniques and tools have flourished in recent years, our approach to management of these perforations has evolved. With the availability of newer tools such as over the scope clips, enhanced through the scope clips and novel endoscopic suturing devices, colonic perforations can be managed effectively in many or most patients without the morbidity of surgical interventions.

SUMMARY

With expanding use of colonoscopy, inadvertent outcomes such as perforations are bound to increase as well. Early diagnosis permits minimally invasive, nonsurgical, endoscopic management in most cases if the expertise and tools are available. Centers with high colonoscopy volumes including therapeutic procedures would be well served to invest in the requisite technologies and expertise.

Interpreting modern randomized controlled trials of medical therapy in inflammatory bowel disease

Treatment options for the medical management of inflammatory bowel disease (IBD) have expanded substantially over the past decade. Multiple classes of advanced therapies, including both monoclonal antibodies and novel oral small molecules, are now available for the treatment of moderately-to-severely active Crohn's disease and ulcerative colitis, highlighted by the approvals of the first IL23p19 antagonists, selective Janus kinase inhibitors and sphingosine-1-phosphate receptor modulators. These advances have been accompanied by the identification of novel targets and the rapid growth in both the number and size of IBD clinical trials. Over a dozen landmark randomized controlled trials (RCTs) have been completed in the past 5 years, including the first head-to-head biologic trials, the first combination biologic studies, and multiple phase III registrational trials of novel compounds with new co-primary and composite end points that will change the treatment landscape for years to come. Importantly, the methodology of RCTs in IBD has evolved substantially, with new trial designs, evaluation of unique patient populations, and different types of efficacy and safety end points being key innovations. In this Review, we provide a comprehensive evaluation of how modern RCTs of IBD medical therapies have evolved and the implications for their appraisal that will help guide the application of these data to clinical practice.

Cost-Utility Analysis of Berberine Chemoprevention for Colorectal Cancer After Polypectomy

Background Chemoprevention, such as berberine, has been developed as an alternative or complementary strategy to colonoscopy surveillance and has shown promise in reducing the morbidity and mortality of colorectal cancer. This study aims to evaluate the cost-effectiveness of berberine for postpolypectomy patients from the US third-party payer. Methods A Markov microsimulation model was developed to compare the cost and efficacy of berberine to no intervention, colonoscopy, and the combination of berberine and colonoscopy in postpolypectomy patients. Results After simulating 1 million patients, the study found that colonoscopy alone had a mean cost of $16,391 and mean quality-adjusted life-years (QALYs) of 16.03 per patient, whereas adding berberine slightly reduced the mean cost to $15,609 with a mean QALY of 16.05, making it a dominant strategy. Berberine therapy alone was less effective than colonoscopy alone, with a higher mean cost of $37,480 and a mean QALY of 15.32 per patient. However, berberine therapy was found to be a dominant strategy over no intervention. Conclusions Adding berberine to colonoscopy is the most cost-saving and effective approach for postpolypectomy patients. For patients who refuse or have limited access to colonoscopy, berberine alone is likely to be a dominant strategy compared to no intervention.

Colorectal cancer screening at age 45 years in Israel: Cost-effectiveness and global implications

BACKGROUND

Colorectal cancer (CRC) incidence at ages <50 years is increasing worldwide. Screening initiation was lowered to 45 years in the United States. The cost-effectiveness of initiating CRC screening at 45 years in Israel was assessed with the aim of informing national policy and addressing internationally relevant questions.

METHODS

A validated CRC screening model was calibrated to Israeli data and examined annual fecal immunochemical testing (FIT) or colonoscopy every 10 years from 45 to 74 years (FIT45-74 or Colo45-74) versus from 50 to 74 years (FIT50-74 or Colo50-74). The addition of a fourth colonoscopy at 75 years was explored, subanalyses were performed by sex/ethnicity, and resource demands were estimated.

RESULTS

FIT50-74 and Colo50-74 reduced CRC incidence by 57% and 70% and mortality by 70% and 77%, respectively, versus no screening, with greater absolute impact in Jews/Other versus Arabs but comparable relative impact. FIT45-74 further reduced CRC incidence and mortality by an absolute 3% and 2%, respectively. With Colo45-74 versus Colo50-74, CRC cases and deaths increased slightly as three colonoscopies per lifetime shifted to 5 years earlier but mean quality-adjusted life-years gained (QALYGs) per person increased. FIT45-74 and Colo45-74 cost 23,800-53,900 new Israeli shekels (NIS)/QALYG and 110,600-162,700 NIS/QALYG, with the lowest and highest values among Jewish/Other men and Arab women, respectively. A fourth lifetime colonoscopy cost 48,700 NIS/QALYG. Lowering FIT initiation to 45 years with modest participation required 19,300 additional colonoscopies in the first 3 years.

CONCLUSIONS

Beginning CRC screening at 45 years in Israel is projected to yield modest clinical benefits at acceptable costs per QALYG. Despite different estimates by sex/ethnicity, a uniform national policy is favored. These findings can inform Israeli guidelines and serve as a case study internationally.

An Assessment of Knowledge, Attitude, and Practice (KAP) of Colorectal Cancer among Community Pharmacists in the Qassim Region of Saudi Arabia

Background: The global burden of colorectal cancer remains a major public health issue and one of the leading causes of death worldwide. In Saudi Arabia, it continues to be a health concern. Any delays in diagnosis for any reason may contribute to advanced complications; therefore, pharmacists' knowledge and awareness of colorectal cancer are crucial for the welfare of society. Studies of colon cancer-related knowledge, attitude, and practice (KAP) among community pharmacists have not previously been conducted in the Al-Qassim region of Saudi Arabia. In the present study, therefore, we sought to investigate the KAP on colon cancer among pharmacists in Al-Qassim. Methods: This was a prospective, cross-sectional, observational study. A sample of 150 community pharmacists was recruited using a convenience sampling method. A self-administered questionnaire was used to evaluate levels of knowledge and practice. Results: Out of a total of 150 pharmacists, the majority of respondents (60.7%) possessed an adequate level of knowledge. About 50% of participants had heard of the early screening test, and 68.7% knew that colonoscopy is necessary in such scenarios. On the basis of their attitudes, 41.3% of study participants were aware of colon cancer symptoms and risk factors. In practice, however, the majority of pharmacists (81%) did not perform early cancer screenings, while 19% did screen when advised to do so by a physician. Conclusions: Our results indicate that pharmacists in Qassim have an adequate level of knowledge of colon cancer in terms of awareness, assessment, and screening. Since community pharmacists are among the most reliable members of the medical community, a greater awareness of colon cancer among pharmacists may improve public knowledge of the disease.

Population health outcomes of blood-based screening for colorectal cancer in comparison to current screening modalities: insights from a discrete-event simulation model incorporating longitudinal adherence

AIM

Insufficient adherence to colorectal cancer (CRC) screening impedes individual and population health benefits, with about one-third of individuals non-adherent to available screening options. The impact of poor adherence is inadequately considered in most health economics models, limiting the evaluation of real-world population-level screening outcomes. This study introduces the CAN-SCREEN (Colorectal cANcer SCReening Economics and adherENce) model, utilizing real-world adherence scenarios to assess the effectiveness of a blood-based test (BBT) compared to existing strategies.

MATERIALS AND METHODS

The CAN-SCREEN model evaluates various CRC screening strategies per 1,000 screened individuals for ages 45-75. Adherence is modeled in two ways: (1) full adherence and (2) longitudinally declining adherence. BBT performance is based on recent pivotal trial data while existing strategies are informed using literature. The full adherence model is calibrated using previously published Cancer Intervention and Surveillance Modeling Network (CISNET) models. Outcomes, including life-years gained (LYG), CRC cases averted, CRC deaths averted, and colonoscopies, are compared to no screening.

RESULTS

Longitudinal adherence modeling reveals differences in the relative ordering of health outcomes and resource utilization, as measured by the number of colonoscopies performed per 1,000, between screening modalities. BBT outperforms the fecal immunochemical test (FIT) and the multitarget stool DNA (mtsDNA) test with more CRC deaths averted (13) compared to FIT and mtsDNA (7, 11), more CRC cases averted (27 vs. 16, 22) and higher LYG (214 vs. 157, 199). BBT yields fewer CRC deaths averted compared to colonoscopy (13, 15) but requires fewer colonoscopies (1,053 vs. 1,928).

LIMITATIONS

Due to limited data, the CAN-SCREEN model with longitudinal adherence leverages evidence-informed assumptions for the natural history and real-world longitudinal adherence to screening.

CONCLUSIONS

The CAN-SCREEN model demonstrates that amongst non-invasive CRC screening strategies, those with higher adherence yield more favorable health outcomes as measured by CRC deaths averted, CRC cases averted, and LYG.

Colonoscopy-induced acute appendicitis: A case report

BACKGROUND

Colonoscopy is widely used for examination, diagnosis, and treatment because of its low incidence of associated complications. Post-colonoscopy appendicitis (PCA) is very rare and is easily misdiagnosed as electrocoagulation syndrome or colon perforation. Therefore, clinicians should pay close attention to this complication.

CASE SUMMARY

A 47-year-old female patient underwent a colonoscopy for a systematic physical examination, and the procedure was uneventful with normal endoscopic and histologic findings. However, the bowel preparation was suboptimal (Boston 2-3-2). After the examination, the patient experienced pain in the lower abdomen, which progressively worsened. Computed tomography of the lower abdomen and pelvis revealed appendiceal calcular obstruction and appendicitis. As the patient refused surgery, she was managed with antibiotics and recovered well.

CONCLUSION

In the current literature, the definition of PCA remains unclear. However, abdominal pain after colonoscopy should be differentiated from acute appendicitis.

Unlocking quality in endoscopic mucosal resection

A review of the development of the key performance metrics of endoscopic mucosal resection (EMR), learning from the experience of the establishment of widespread colonoscopy quality measurements. Potential future performance markers for both colonoscopy and EMR are also evaluated to ensure continued high quality performance is maintained with a focus service framework and predictors of patient outcome.

Characteristics and endoscopic treatment of interventional and non-interventional iatrogenic colorectal perforations in centers with high endoscopic expertise: a retrospective multicenter study

BACKGROUND

Iatrogenic colorectal perforation is a rare event with a relevant mortality and the need for surgical therapy in around ¾ of cases.

METHODS

In this retrospective multicentric cohort study iatrogenic colorectal perforations from 2004 to 2021 were analyzed. Primary outcome parameters were incidence and clinical success of 1st line endoscopic treatment. Comparative analysis of interventional and non-interventional perforations was performed and predictors for clinical success of endoscopic therapy were identified.

RESULTS

From 103,570 colonoscopies 213 (0.2%) iatrogenic perforations were identified. 68.4% were interventional (80 during polypectomy/EMR, 54 during ESD and 11 for other reasons) and 31.6% non-interventional perforations (39 by the tip, 19 by the shaft, 7 by inversion, two by biopsy and one by distension). Incidence of 1st line endoscopic therapy was 61.0% and clinical success 81.5%. Other non-surgical therapies were conducted in 8.9% with clinical success in 94.7% of cases. In interventional perforations both incidence and clinical success of 1st line endoscopic therapy were significantly higher compared to non-interventional perforations [71.7% vs. 38.2% (p < 0.01) resp. 86.5% vs. 61.5% (p < 0.01)]. Mortality was 2.3% and significantly lower in the group of interventional perforations (0.7% vs. 5.9%, p = 0.037). Multivariable analysis revealed perforation size < 5 mm as only independent predictor for clinical success of 1st line endoscopic treatment [OR 14.85 (1.57-140.69), p = 0.019].

CONCLUSIONS

Endoscopic therapy is treatment of choice in the majority of iatrogenic colorectal perforations. In case of interventional perforations it is highly effective but only a minority of non-interventional perforations are good candidates for endoscopic treatment.

JAG consensus statements for training and certification in flexible sigmoidoscopy

INTRODUCTION

Joint Advisory Group (JAG) certification in endoscopy is awarded when trainees attain minimum competency standards for independent practice. A national evidence-based review was undertaken to update standards for training and certification in flexible sigmoidoscopy (FS).

METHODS

A modified Delphi process was conducted between 2019 and 2020 with multisociety representation from experts and trainees. Following literature review and Grading of Recommendations, Assessment, Development and Evaluations appraisal, recommendation statements on FS training and certification were formulated and subjected to anonymous voting to obtain consensus. Accepted statements were peer-reviewed by national stakeholders for incorporation into the JAG FS certification pathway.

RESULTS

In total, 41 recommendation statements were generated under the domains of: definition of competence (13), acquisition of competence (17), assessment of competence (7) and postcertification support (4). The consensus process led to revised criteria for colonoscopy certification, comprising: (A) achieving key performance indicators defined within British Society of Gastroenterology standards (ie, rectal retroversion >90%, polyp retrieval rate >90%, patient comfort <10% with moderate-severe discomfort); (B) minimum procedure count ≥175; (C) performing 15+ procedures over the preceding 3 months; (D) attendance of the JAG Basic Skills in Lower gastrointestinal Endoscopy course; (E) satisfying requirements for formative direct observation of procedural skill (DOPS) and direct observation of polypectomy skill (SMSA level 1); (F) evidence of reflective practice as documented on the JAG Endoscopy Training System reflection tool and (G) successful performance in summative DOPS.

CONCLUSION

The UK standards for training and certification in FS have been updated to support training, uphold standards in FS and polypectomy, and provide support to the newly independent practitioner.

Postoperative Sigmoidoscopy and Biopsy After Elective Endovascular and Open Aortic Surgery for Preventing Mortality by Colonic Ischemia (PSB-Aorta-CI): Protocol for a Prospective Study

BACKGROUND

Endovascular aortic repair is considered the standard procedure in treating patients diagnosed with pathologies of the abdominal aorta with suitable anatomy. Open surgery remains an option mostly for patients not suitable for endovascular surgery. Colonic ischemia is an important and life-threatening postoperative complication of these procedures.

OBJECTIVE

The aim of this study is to evaluate the clinical value and safety of performing a planned sigmoidoscopy and biopsy for detection of colonic ischemia in patients undergoing elective aortic surgery. We also aim to develop prediction scores which could identify patients at risk for colonic ischemia and facilitate their timely treatment.

METHODS

The trial is designed as a prospective study. The decision for aortic surgery and eligibility for these procedures will be ascertained according to current guidelines. Afterward, screening of the patient for the remaining inclusion and exclusion criteria will occur. If eligibility for study inclusion is confirmed, the patient will be informed about the aims of the study and all study-specific procedures (sigmoidoscopy and biopsy) and asked to provide informed consent.

RESULTS

The primary end point is the proportion of patients diagnosed endoscopically with subclinical and clinically relevant colonic ischemia among all patients undergoing aortic surgery. Patient recruitment started on June 2021. The final patient is expected to be treated by the end of June 2023. Institutional Review Board review has been completed at the University of Halle (Saale; reference #052-2021).

CONCLUSIONS

this shows that sigmoidoscopy can be performed safely and is effective for the timely diagnosis of colonic ischemia in these patients, this could result in its routine implementation in both elective and emergency settings.

TRIAL REGISTRATION

German Clinical Trials Register DRKS00025587; https://www.drks.de/drks_web/navigate.do?navigationId =trial.HTML&TRIAL_ID=DRKS00025587.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

DERR1-10.2196/39071.

Cost-Effectiveness of Colorectal Cancer Surveillance in Hodgkin Lymphoma Survivors Treated with Procarbazine and/or Infradiaphragmatic Radiotherapy

BACKGROUND

Hodgkin lymphoma survivors treated with infradiaphragmatic radiotherapy (IRT) and/or procarbazine have an increased risk of developing colorectal cancer. We investigated the cost-effectiveness of colorectal cancer surveillance in Dutch Hodgkin lymphoma survivors to determine the optimal surveillance strategy for different Hodgkin lymphoma subgroups.

METHODS

The Microsimulation Screening Analysis-Colon model was adjusted to reflect colorectal cancer and other-cause mortality risk in Hodgkin lymphoma survivors. Ninety colorectal cancer surveillance strategies were evaluated varying in starting and stopping age, interval, and modality [colonoscopy, fecal immunochemical test (FIT, OC-Sensor; cutoffs: 10/20/47 μg Hb/g feces), and multi-target stool DNA test (Cologuard)]. Analyses were also stratified per primary treatment (IRT and procarbazine or procarbazine without IRT). Colorectal cancer deaths averted (compared with no surveillance) and incremental cost-effectiveness ratios (ICER) were primary outcomes. The optimal surveillance strategy was identified assuming a willingness-to-pay threshold of €20,000 per life-years gained (LYG).

RESULTS

Overall, the optimal surveillance strategy was annual FIT (47 μg) from age 45 to 70 years, which might avert 70% of colorectal cancer deaths in Hodgkin lymphoma survivors (compared with no surveillance; ICER:€18,000/LYG). The optimal surveillance strategy in Hodgkin lymphoma survivors treated with procarbazine without IRT was biennial FIT (47 μg) from age 45 to 70 years (colorectal cancer mortality averted 56%; ICER:€15,000/LYG), and when treated with IRT and procarbazine, annual FIT (47 μg) surveillance from age 40 to 70 was most cost-effective (colorectal cancer mortality averted 75%; ICER:€13,000/LYG).

CONCLUSIONS

Colorectal cancer surveillance in Hodgkin lymphoma survivors is cost-effective and should commence earlier than screening occurs in population screening programs. For all subgroups, FIT surveillance was the most cost-effective strategy.

IMPACT

Colorectal cancer surveillance should be implemented in Hodgkin lymphoma survivors.

Impact of surgical versus endoscopic management of complex nonmalignant polyps in a colorectal cancer screening program

BACKGROUND

When complex nonmalignant polyps are detected in colorectal cancer (CRC) screening programs, patients may be referred directly to surgery or may first undergo additional endoscopy for attempted endoscopic removal by an expert. We compared the impact of both strategies on screening effectiveness and costs.

METHODS

We used MISCAN-Colon to simulate the Dutch screening program, and projected CRC deaths prevented, quality-adjusted life-years (QALYs) gained, and costs for two scenarios: 1) surgery for all complex nonmalignant polyps; 2) attempted removal by an expert endoscopist first. We made the following assumptions: 3.9 % of screen-detected large nonmalignant polyps were complex; associated surgery mortality was 0.7 %; the rate of successful removal by an expert was 87 %, with 0.11 % mortality.

RESULTS

The screening program was estimated to prevent 11.2 CRC cases (-16.7 %) and 10.1 CRC deaths (-27.1 %), resulting in 32.9 QALYs gained (+ 17.2 %) per 1000 simulated individuals over their lifetimes compared with no screening. The program would also result in 2.1 surgeries for complex nonmalignant polyps with 0.015 associated deaths per 1000 individuals. If, instead, these patients were referred to an expert endoscopist first, only 0.2 patients required surgery, reducing associated deaths by 0.013 at the expense of 0.003 extra colonoscopy deaths. Compared with direct referral to surgery, referral to an expert endoscopist gained 0.2 QALYs and saved €12 500 per 1000 individuals in the target population.

CONCLUSION

Referring patients with complex polyps to an expert endoscopist first reduced some surgery-related deaths while substantially improving cost-effectiveness of the screening program.

Practical considerations for colorectal cancer screening in older adults

Recent guidelines recommend that colorectal cancer (CRC) screening after age 75 be considered on an individualized basis, and discourage screening for people over 85 due to competing causes of mortality. Given the heterogeneity in the health of older individuals, and lack of data within current guidelines for personalized CRC screening approaches, there remains a need for a clearer framework to inform clinical decision-making. A revision of the current approach to CRC screening in older adults is even more compelling given the improvements in CRC treatment, post-treatment survival, and increasing life expectancy in the population. In this review, we aim to examine the personalization of CRC screening cessation based on specific factors influencing life and health expectancy such as comorbidity, frailty, and cognitive status. We will also review screening modalities and endoscopic technique for minimizing risk, the risks of screening unique to older adults, and CRC treatment outcomes in older patients, in order to provide important information to aid CRC screening decisions for this age group. This review article offers a unique approach to this topic from both the gastroenterologist and geriatrician perspective by reviewing the use of specific clinical assessment tools, and addressing technical aspects of screening colonoscopy and periprocedural management to mitigate screening-related complications.

Effectiveness and Harms of Colorectal Cancer Screening Strategies

Colorectal cancer screening incorporates various testing modalities. Factors including effectiveness, harms, cost, screening interval, patient preferences, and test availability should be considered when determining which test to use. Fecal occult blood testing and endoscopic screening have the most robust evidence, while newer blood- and imaging-based techniques require further evaluation. In this review, we compare the effectiveness, harms, and costs of the various screening strategies.

Adherence to colonoscopy in cascade screening of colorectal cancer: A systematic review and meta-analysis

BACKGROUND AND AIM

This study aims to systematically evaluate adherence to colonoscopy and related factors in cascade screening of colorectal cancer (CRC) among average-risk populations, which is crucial to achieve the effectiveness of CRC screening.

METHODS

We searched PubMed, Embase, Web of Science, and Cochrane Library for studies published in English up to October 16, 2020, and reporting the adherence to colonoscopy following positive results of initial screening tests. A random-effects meta-analysis was applied to estimate pooled adherence and 95% confidence intervals. Subgroup analysis and mixed-effects meta-regression analysis were performed to evaluate heterogeneous factors for adherence level.

RESULTS

A total of 245 observational and 97 experimental studies were included and generated a pooled adherence to colonoscopy of 76.6% (95% confidence interval: 74.1-78.9) and 80.4% (95% confidence interval: 77.2-83.1), respectively. The adherence varied substantially by calendar year of screening, continents, CRC incidence, socioeconomic status, recruitment methods, and type of initial screening tests, with the initial tests as the most modifiable heterogeneous factor for adherence across both observational (Q = 162.6, P < 0.001) and experimental studies (Q = 23.2, P < 0.001). The adherence to colonoscopy was at the highest level when using flexible sigmoidoscopy as an initial test, followed by using guaiac fecal occult blood test, quantitative or qualitative fecal immunochemical test, and risk assessment. The pooled estimate of adherence was positively associated with specificity and positive predictive value of initial screening tests, but negatively with sensitivity and positivity rate.

CONCLUSIONS

Colonoscopy adherence is at a low level and differs by study-level characteristics of programs and populations. Initial screening tests with high specificity or positive predictive value may be followed by a high adherence to colonoscopy.

Polypectomy for Diminutive and Small Colorectal Polyps

Diminutive and small colorectal polyps are common findings during colonoscopies, and rarely contain dysplastic elements and progress to colorectal cancer. With improving technology and the advent of artificial intelligence, detection rates of small or diminutive polyps and adenomas are rising, resulting in increasing costs associated with colonoscopy. Incomplete resection rates are an outcome of interest because it correlates with interval colorectal cancer. More effort is warranted to standardize training programs and sensitize endoscopists to the importance of personal performance as a quality metric of colonoscopy. This article reviews indications, methods, and recent developments in polypectomy for small and diminutive polyps.

Optimizing screening with faecal immunochemical test for both sexes - Cost-effectiveness analysis from Finland

A faecal immunochemical test (FIT) screening pilot was introduced in Finland in 2019 with sex-specific screening strategies. This study aims to model cost-effectiveness of sex-specific strategies for the whole population, and to assess whether the current strategies are optimal. We developed separate MISCAN-Colon models, including different FIT performances, for the Finnish men and women using the first-year data of the FIT screening pilot. We evaluated 180 FIT strategies varying in FIT cut-off, screening interval, age to start, and age to stop screening, and compared them to no-screening by sex. We used incremental cost-effectiveness ratios (ICERs) to identify the optimal strategy after combining all male and female strategies and restricting the analysis by costs and referral rate to diagnostic colonoscopies. Offering annual FIT screening with a cut-off of 25 μg/g at 50-79 years in men and with a cut-off of 10 μg/g at 55-69 years in women was optimal. This combined strategy prevented 28% of colorectal cancer (CRC) cases and 55% of CRC deaths with acceptable costs (ICER = 9000€/life-years gained). Screening at the current target age of 60-74 years was suboptimal for both sexes. Among strategies with the same target age and interval for both sexes, expected benefits from optimal screening were lower but still reasonable. Our results support a wider age range of screening in men, and a lower cut-off for a positive test in women when restrictions on colonoscopy capacity and costs are in place. National FIT screening program should start at younger age.

Pediatric Endoscopy Quality Improvement Network Quality Standards and Indicators for Pediatric Endoscopy Facilities: A Joint NASPGHAN/ESPGHAN Guideline

INTRODUCTION

There is increasing international recognition of the impact of variability in endoscopy facilities on procedural quality and outcomes. There is also growing precedent for assessing the quality of endoscopy facilities at regional and national levels by using standardized rating scales to identify opportunities for improvement.

METHODS

With support from the North American and European Societies of Pediatric Gastroenterology Hepatology and Nutrition (NASPGHAN and ESPGHAN), an international working group of the Pediatric Endoscopy Quality Improvement Network (PEnQuIN) used the methodological strategy of the Appraisal of Guidelines for REsearch and Evaluation (AGREE) II instrument to develop standards and indicators relevant for assessing the quality of facilities where endoscopic care is provided to children. Consensus was reached via an iterative online Delphi process and subsequent in-person meeting. The quality of evidence and strength of recommendations were rated according to the GRADE (Grading of Recommendation Assessment, Development and Evaluation) approach.

RESULTS

The PEnQuIN working group achieved consensus on 27 standards for facilities supporting pediatric endoscopy, as well 10 indicators that can be used to identify high-quality endoscopic care in children. These standards were subcategorized into three subdomains: Quality of Clinical Operations (15 standards, 5 indicators); Patient and Caregiver Experience (9 standards, 5 indicators); and Workforce (3 standards).

DISCUSSION

The rigorous PEnQuIN process successfully yielded standards and indicators that can be used to universally guide and measure high-quality facilities for procedures around the world where endoscopy is performed in children. It also underscores the current paucity of evidence for pediatric endoscopic care processes, and the need for research into this clinical area.

The Costs and Benefits of Risk Stratification for Colorectal Cancer Screening Based On Phenotypic and Genetic Risk: A Health Economic Analysis

Population-based screening for colorectal cancer is an effective and cost-effective way of reducing colorectal cancer incidence and mortality. Many genetic and phenotypic risk factors for colorectal cancer have been identified, leading to development of colorectal cancer risk scores with varying discrimination. However, these are not currently used by population screening programs. We performed an economic analysis to assess the cost-effectiveness, clinical outcomes, and resource impact of using risk-stratification based on phenotypic and genetic risk, taking a UK National Health Service perspective. Biennial fecal immunochemical test (FIT), starting at an age determined through risk-assessment at age 40, was compared with FIT screening starting at a fixed age for all individuals. Compared with inviting everyone from age 60, using a risk score with area under the receiver operating characteristic curve of 0.721 to determine FIT screening start age, produces 418 QALYs, costs £247,000, and results in 218 fewer colorectal cancer cases and 156 fewer colorectal cancer deaths per 100,000 people, with similar FIT screening invites. There is 96% probability that risk-stratification is cost-effective, with net monetary benefit (based on £20,000 per QALY threshold) estimated at £8.1 million per 100,000 people. The maximum that could be spent on risk-assessment and still be cost-effective is £114 per person. Lower benefits are produced with lower discrimination risk scores, lower mean screening start age, or higher FIT thresholds. Risk-stratified screening benefits men more than women. Using risk to determine FIT screening start age could improve the clinical outcomes and cost effectiveness of colorectal cancer screening without using significant additional screening resources. PREVENTION RELEVANCE: Colorectal cancer screening is essential for early detection and prevention of colorectal cancer, but implementation is often limited by resource constraints. This work shows that risk-stratification using genetic and phenotypic risk could improve the effectiveness and cost-effectiveness of screening programs, without using substantially more screening resources than are currently available.

Gastrointestinal and Nongastrointestinal Complications of Esophagogastroduodenoscopy and Colonoscopy in the Real World: A Nationwide Standard Cohort Using the Common Data Model Database

Background/Aims

The global trend of an expanding aged population has increased concerns about complications correlated with gastrointestinal (GI) endoscopy in elderly patients; however, there have been few reports published on this issue.

Methods

In this retrospective, observational cohort study performed between 2012 and 2017, serious complications of esophagogastroduodenoscopy (EGD), colonoscopy, and colonoscopic polypectomy were compared between patients according to age (≥65 years vs 18–64 years). We used the Health Insurance Review and Assessment-National Patient Samples database, previously converted to the standardized Observational Medical Outcomes Partnership-Common Data Model. Serious complications within 30 days of the procedure included both GI complications (bleeding and perforation) and non-GI complications (cerebrovascular accident [CVA], acute myocardial infarction [AMI], congestive heart failure [CHF], and death).

Results

A total of 387,647 patients who underwent EGD, 241,094 who underwent colonoscopy, and 89,059 who underwent colonoscopic polypectomy were assessed as part of this investigation. During the study period, endoscopic procedures in the older group steadily increased in number in all endoscopy groups (all p<0.001). Further, pooled complication rates of bleeding, CVA, AMI, CHF, and death were approximately three times higher among older patients who underwent EGD or colonoscopy. Moreover, pooled complication rates of CVA, AMI, CHF, and death were approximately 2.2 to 5.0 times higher among older patients who underwent colonoscopic polypectomy.

Conclusions

Elderly patients experienced approximately three times more GI and non-GI complications after EGD or colonoscopy than young patients. Physicians should pay attention to the potential risks of GI endoscopy in elderly patients.

Management of Less Than 10-mm-Sized Pedunculated (Ip) Polyps with Thin Stalk: Hot Snare Polypectomy Versus Cold Snare Polypectomy

BACKGROUND

Although the use of cold snare polypectomy (CSP) has spread rapidly, its safety for pedunculated (Ip) polyps remains controversial. In particular, the outcomes of hot snare polypectomy (HSP) and CSP for Ip polyps have not been previously compared.

AIMS

This study evaluated whether the rate of delayed postpolypectomy bleeding (DPPB) after CSP for Ip polyps was higher than that after HSP for Ip polyps and compared other outcomes (the rates of immediate bleeding and pathological margins) between the HSP and CSP procedures.

METHODS

A total of 5905 colorectal polyps in 4920 patients were resected at Omori Red Cross Hospital between October 2012 and June 2019. The polyps were divided into two groups: the HSP group (86 polyps, 64 patients) and the CSP group (102 polyps, 87 patients). The primary outcome measure was the incidence of DPPB. The secondary outcome measures were the incidences of immediate bleeding during the procedure and pathological margins of the resected specimen.

RESULTS

The rate of immediate bleeding during CSP was significantly higher than that for the HSP group [38.2% (39/102) versus 3.5% (3/86); p < 0.001]. However, the rate of DPPB was significantly higher in the HSP group than in the CSP group [4.7% (4/86) versus 0% (0/102); p < 0.001]. The rate of DPPB after CSP was 0%.

CONCLUSIONS

This is the first study to compare the outcomes of HSP and CSP for Ip polyps. CSP is safer than HSP for Ip polyps measuring < 10 mm in diameter.

Association of Screening Lower Endoscopy With Colorectal Cancer Incidence and Mortality in Adults Older Than 75 Years

Importance

Evidence indicates that screening for colorectal cancer (CRC) beginning at 50 years of age can detect early-stage CRC and premalignant neoplasms (eg, adenomas) and thus prevent CRC-related mortality. At present, the US Preventive Services Task Force recommends continuing CRC screening until 75 years of age and individualized decision-making for adults older than 75 years, while accounting for a patient's overall health and screening history. However, scant data exist to support these recommendations.

Objective

To examine the association of lower gastrointestinal tract screening endoscopy with the risk of CRC incidence and CRC-related mortality in older US adults.

Design, Setting, and Participants

This prospective cohort study of health care professionals in the US included data from the Nurses' Health Study (NHS) and Health Professionals Follow-up Study (HPFS) from January 1, 1988, through January 31, 2016, for the HPFS and June 30, 2016, for the NHS. Data were analyzed from May 8, 2019, to July 9, 2020.

Exposures

History of screening sigmoidoscopy or colonoscopy (routine/average risk or positive family history) to 75 years of age and after 75 years of age, assessed every 2 years.

Main Outcomes and Measures

Incidence of CRC and CRC-related mortality confirmed by National Death Index, medical records, and pathology reports.

Results

Among 56 374 participants who reached 75 years of age during follow-up (36.8% men and 63.2% women), 661 incident CRC cases and 323 CRC-related deaths were documented. Screening endoscopy after 75 years of age was associated with reduced risk of CRC incidence (multivariable hazard ratio [HR], 0.61; 95% CI, 0.51-0.74) and CRC-related mortality (HR, 0.60; 95% CI, 0.46-0.78), regardless of screening history. The HR comparing screening with nonscreening after 75 years of age was 0.67 (95% CI, 0.50-0.89) for CRC incidence and 0.58 (95% CI, 0.38-0.87) for CRC-related mortality among participants who underwent screening endoscopy before 75 years of age, and 0.51 (95% CI, 0.37-0.70) for CRC incidence and 0.63 (95% CI, 0.43-0.93) for CRC-related mortality among participants without a screening history. However, screening endoscopy after 75 years of age was not associated with risk reduction in CRC death among participants with cardiovascular disease (HR, 1.18; 95% CI, 0.59-2.35) or significant comorbidities (HR, 1.17; 95% CI, 0.57-2.43).

Conclusions and Relevance

In this cohort study, endoscopy among individuals older than 75 years was associated with lower risk of CRC incidence and CRC-related mortality. These data support continuation of screening after 75 years of age among individuals without significant comorbidities.

Prioritisation by FIT to mitigate the impact of delays in the 2-week wait colorectal cancer referral pathway during the COVID-19 pandemic: a UK modelling study

OBJECTIVE

To evaluate the impact of faecal immunochemical testing (FIT) prioritisation to mitigate the impact of delays in the colorectal cancer (CRC) urgent diagnostic (2-week-wait (2WW)) pathway consequent from the COVID-19 pandemic.

DESIGN

We modelled the reduction in CRC survival and life years lost resultant from per-patient delays of 2-6 months in the 2WW pathway. We stratified by age group, individual-level benefit in CRC survival versus age-specific nosocomial COVID-19-related fatality per referred patient undergoing colonoscopy. We modelled mitigation strategies using thresholds of FIT triage of 2, 10 and 150 µg Hb/g to prioritise 2WW referrals for colonoscopy. To construct the underlying models, we employed 10-year net CRC survival for England 2008-2017, 2WW pathway CRC case and referral volumes and per-day-delay HRs generated from observational studies of diagnosis-to-treatment interval.

RESULTS

Delay of 2/4/6 months across all 11 266 patients with CRC diagnosed per typical year via the 2WW pathway were estimated to result in 653/1419/2250 attributable deaths and loss of 9214/20 315/32 799 life years. Risk-benefit from urgent investigatory referral is particularly sensitive to nosocomial COVID-19 rates for patients aged >60. Prioritisation out of delay for the 18% of symptomatic referrals with FIT >10 µg Hb/g would avoid 89% of these deaths attributable to presentational/diagnostic delay while reducing immediate requirement for colonoscopy by >80%.

CONCLUSIONS

Delays in the pathway to CRC diagnosis and treatment have potential to cause significant mortality and loss of life years. FIT triage of symptomatic patients in primary care could streamline access to colonoscopy, reduce delays for true-positive CRC cases and reduce nosocomial COVID-19 mortality in older true-negative 2WW referrals. However, this strategy offers benefit only in short-term rationalisation of limited endoscopy services: the appreciable false-negative rate of FIT in symptomatic patients means most colonoscopies will still be required.

Colorectal Cancer Screening: An Updated Modeling Study for the US Preventive Services Task Force

Importance

The US Preventive Services Task Force (USPSTF) is updating its 2016 colorectal cancer screening recommendations.

Objective

To provide updated model-based estimates of the benefits, burden, and harms of colorectal cancer screening strategies and to identify strategies that may provide an efficient balance of life-years gained (LYG) from screening and colonoscopy burden to inform the USPSTF.

Design, Setting, and Participants

Comparative modeling study using 3 microsimulation models of colorectal cancer screening in a hypothetical cohort of 40-year-old US individuals at average risk of colorectal cancer.

Exposures

Screening from ages 45, 50, or 55 years to ages 70, 75, 80, or 85 years with fecal immunochemical testing (FIT), multitarget stool DNA testing, flexible sigmoidoscopy alone or with FIT, computed tomography colonography, or colonoscopy. All persons with an abnormal noncolonoscopy screening test result were assumed to undergo follow-up colonoscopy. Screening intervals varied by test. Full adherence with all procedures was assumed.

Main Outcome and Measures

Estimated LYG relative to no screening (benefit), lifetime number of colonoscopies (burden), number of complications from screening (harms), and balance of incremental burden and benefit (efficiency ratios). Efficient strategies were those estimated to require fewer additional colonoscopies per additional LYG relative to other strategies.

Results

Estimated LYG from screening strategies ranged from 171 to 381 per 1000 40-year-olds. Lifetime colonoscopy burden ranged from 624 to 6817 per 1000 individuals, and screening complications ranged from 5 to 22 per 1000 individuals. Among the 49 strategies that were efficient options with all 3 models, 41 specified screening beginning at age 45. No single age to end screening was predominant among the efficient strategies, although the additional LYG from continuing screening after age 75 were generally small. With the exception of a 5-year interval for computed tomography colonography, no screening interval predominated among the efficient strategies for each modality. Among the strategies highlighted in the 2016 USPSTF recommendation, lowering the age to begin screening from 50 to 45 years was estimated to result in 22 to 27 additional LYG, 161 to 784 additional colonoscopies, and 0.1 to 2 additional complications per 1000 persons (ranges are across screening strategies, based on mean estimates across models). Assuming full adherence, screening outcomes and efficient strategies were similar by sex and race and across 3 scenarios for population risk of colorectal cancer.

Conclusions and Relevance

This microsimulation modeling analysis suggests that screening for colorectal cancer with stool tests, endoscopic tests, or computed tomography colonography starting at age 45 years provides an efficient balance of colonoscopy burden and life-years gained.

Cost-Effectiveness of Multitarget Stool DNA Testing vs Colonoscopy or Fecal Immunochemical Testing for Colorectal Cancer Screening in Alaska Native People

OBJECTIVE

To estimate the cost-effectiveness of multitarget stool DNA testing (MT-sDNA) compared with colonoscopy and fecal immunochemical testing (FIT) for Alaska Native adults.

PATIENTS AND METHODS

A Markov model was used to evaluate the 3 screening test effects over 40 years. Outcomes included colorectal cancer (CRC) incidence and mortality, costs, quality-adjusted life-years (QALYs), and incremental cost-effectiveness ratios (ICERs). The study incorporated updated evidence on screening test performance and adherence and was conducted from December 15, 2016, through November 6, 2019.

RESULTS

With perfect adherence, CRC incidence was reduced by 52% (95% CI, 46% to 56%) using colonoscopy, 61% (95% CI, 57% to 64%) using annual FIT, and 66% (95% CI, 63% to 68%) using MT-sDNA. Compared with no screening, perfect adherence screening extends life by 0.15, 0.17, and 0.19 QALYs per person with colonoscopy, FIT, and MT-sDNA, respectively. Colonoscopy is the most expensive strategy: approximately $110 million more than MT-sDNA and $127 million more than FIT. With imperfect adherence (best case), MT-sDNA resulted in 0.12 QALYs per person vs 0.05 and 0.06 QALYs per person by FIT and colonoscopy, respectively. Probabilistic sensitivity analyses supported the base-case analysis. Under varied adherence scenarios, MT-sDNA either dominates or is cost-effective (ICERs, $1740-$75,868 per QALY saved) compared with FIT and colonoscopy.

CONCLUSION

Each strategy reduced costs and increased QALYs compared with no screening. Screening by MT-sDNA results in the largest QALY savings. In Markov model analysis, screening by MT-sDNA in the Alaska Native population was cost-effective compared with screening by colonoscopy and FIT for a wide range of adherence scenarios.

Risk of Gastrointestinal Endoscopic Procedure-Related Bleeding in Patients With or Without Continued Antithrombotic Therapy

BACKGROUND

Prospective studies on bleeding risk during/after gastrointestinal endoscopic procedures are rare.

AIM

We investigated the risk of endoscopic procedure-related bleeding in patients with biopsy and/or cold snare polypectomy (CSP) in relation to antithrombotic therapy.

METHODS

This prospective, observational single-center cohort study (NCT02594813) enrolled consecutive patients who underwent diagnostic esophagogastroduodenoscopy (EGD) or colonoscopy. The primary outcome measure was delayed bleeding in patients with biopsy and/or CSP who required endoscopic treatment within 2 weeks post-procedure. The secondary outcomes were immediate bleeding and the number of hemostatic clips used during the procedure.

RESULTS

From November 2015 to October 2018 at our institution, 3069 (mean age, 66 years) and 37,887 (57 years) patients underwent EGD with and without antithrombotic therapy, respectively. In addition, 1116 (72 years) and 11,901 (65 years) patients had colonoscopy with and without antithrombotic therapy, respectively. In the 3069 EGD patients receiving antithrombotic therapy, no delayed bleeding occurred, whereas immediate bleeding occurred in 9 of 141 patients (6.4%) with biopsy. Of the 1116 colonoscopy patients receiving antithrombotic therapy, delayed bleeding occurred in three of 228 (1.3%) following CSP. Immediate bleeding occurred in nine of 225 (4%) following biopsy and in 32 of 228 (14%) following CSP. Multivariate analysis following univariate analysis identified chronic kidney disease and CSP as factors significantly associated with procedure-related bleeding in patients taking antithrombotic agents.

CONCLUSION

The risk of delayed bleeding in diagnostic EGD with biopsy or in colonoscopy with biopsy and/or CSP was low despite continuation of antithrombotic therapy.

Cost-effectiveness analysis of colorectal cancer screening in a low incidence country: The case of Saudi Arabia

BACKGROUND

Colorectal cancer (CRC) screening is cost-effective in many Western countries, and many have successfully implemented CRC screening programs. For countries with a lower CRC incidence, like Saudi Arabia, the value of CRC screening is less evident and requires careful weighing of harms, benefits, and costs.

METHODS

We used the MISCAN-Colon microsimulation model to simulate a male and female cohort with life expectancy and CRC risk as observed in Saudi Arabia. For both cohorts, we evaluated strategies without screening, with annual or biennial faecal immunochemical testing (FIT), and with 10-yearly or once-only colonoscopy. We also considered different start and end ages of screening. For both cohorts, we estimated lifetime costs and effects of each strategy. We then identified a set of potentially cost-effective strategies using incremental cost-effectiveness ratios (ICERs) defined as the additional cost per additional quality-adjusted life year (QALY).

RESULTS

Without CRC screening, an estimated 14 per 1,000 males would develop CRC during their lifetime and 9 would die from CRC. Several strategies proved potentially cost-effective including biennial FIT at ages 55-65 (ICER of $7,400), once-only colonoscopy at age 55 (ICER of $7,700), and 10-yearly colonoscopy at ages 50-65, 45-65, and 45-75 (ICERs of $34,000, 71,000, and 375,000, respectively). For females, risk of CRC was lower and CRC screening was therefore less cost-effective, but efficient strategies were largely similar.

CONCLUSIONS

Despite low CRC incidence in Saudi Arabia, some FIT or colonoscopy screening strategies may meet reasonable thresholds of cost-effectiveness. The optimal strategy will depend on multiple factors including the willingness to pay per QALY, the colonoscopy capacity, and the accepted budget impact.

Impact of screening and follow-up colonoscopy adenoma sensitivity on colorectal cancer screening outcomes in the CRC-AIM microsimulation model

BACKGROUND

Real-world data for patients with positive colorectal cancer (CRC) screening stool-tests demonstrate that adenoma detection rates are lower when endoscopists are blinded to the stool-test results. This suggests adenoma sensitivity may be lower for screening colonoscopy than for follow-up to a known positive stool-based test. Previous CRC microsimulation models assume identical sensitivities between screening and follow-up colonoscopies after positive stool-tests. The Colorectal Cancer and Adenoma Incidence and Mortality Microsimulation Model (CRC-AIM) was used to explore the impact on screening outcomes when assuming different adenoma sensitivity between screening and combined follow-up/surveillance colonoscopies.

METHODS

Modeled screening strategies included colonoscopy every 10 years, triennial multitarget stool DNA (mt-sDNA), or annual fecal immunochemical test (FIT) from 50 to 75 years. Outcomes were reported per 1000 individuals without diagnosed CRC at age 40. Base-case adenoma sensitivity values were identical for screening and follow-up/surveillance colonoscopies. Ranges of adenoma sensitivity values for colonoscopy performance were developed using different slopes of odds ratio adjustments and were designated as small, medium, or large impact scenarios.

RESULTS

As the differences in adenoma sensitivity for screening versus follow-up/surveillance colonoscopies became greater, life-years gained (LYG) and reductions in CRC-related incidence and mortality versus no screening increased for mt-sDNA and FIT and decreased for screening colonoscopy. The LYG relative to screening colonoscopy reached >90% with FIT in the base-case scenario and with mt-sDNA in a "medium impact" scenario.

CONCLUSIONS

Assuming identical adenoma sensitivities for screening and follow-up/surveillance colonoscopies underestimate the potential benefits of stool-based screening strategies.

Very-low-dose aspirin and surveillance colonoscopy is cost-effective in secondary prevention of colorectal cancer in individuals with advanced adenomas: network meta-analysis and cost-effectiveness analysis

BACKGROUND

Individuals with advanced colorectal adenomas (ACAs) are at high risk for colorectal cancer (CRC), and it is unclear which chemopreventive agent (CPA) is safe and cost-effective for secondary prevention. We aimed to determine, firstly, the most suitable CPA using network meta-analysis (NMA) and secondly, cost-effectiveness of CPA with or without surveillance colonoscopy (SC).

METHODS

Systematic review and NMA of randomised controlled trials were performed, and the most suitable CPA was chosen based on efficacy and the most favourable risk-benefit profile. The economic benefits of CPA alone, 3 yearly SC alone, and a combination of CPA and SC were determined using the cost-effectiveness analysis (CEA) in the Malaysian health-care perspective. Outcomes were reported as incremental cost-effectiveness ratios (ICERs) in 2018 US Dollars ($) per quality-adjusted life-year (QALY), and life-years (LYs) gained.

RESULTS

According to NMA, the risk-benefit profile favours the use of aspirin at very-low-dose (ASAVLD, ≤ 100 mg/day) for secondary prevention in individuals with previous ACAs. Celecoxib is the most effective CPA but the cardiovascular adverse events are of concern. According to CEA, the combination strategy (ASAVLD with 3-yearly SC) was cost-saving and dominates its competitors as the best buy option. The probability of being cost-effective for ASAVLD alone, 3-yearly SC alone, and combination strategy were 22%, 26%, and 53%, respectively. Extending the SC interval to five years in combination strategy was more cost-effective when compared to 3-yearly SC alone (ICER of $484/LY gain and $1875/QALY). However, extending to ten years in combination strategy was not cost-effective.

CONCLUSION

ASAVLD combined with 3-yearly SC in individuals with ACAs may be a cost-effective strategy for CRC prevention. An extension of SC intervals to five years can be considered in resource-limited countries.

Computed tomography colonography and radiation risk: How low can we go?

Computed tomography colonography (CTC) has become a key examination in detecting colonic polyps and colorectal carcinoma (CRC). It is particularly useful after incomplete optical colonoscopy (OC) for patients with sedation risks and patients anxious about the risks or potential discomfort associated with OC. CTC's main advantages compared with OC are its non-invasive nature, better patient compliance, and the ability to assess the extracolonic disease. Despite these advantages, ionizing radiation remains the most significant burden of CTC. This opinion review comprehensively addresses the radiation risk of CTC, incorporating imaging technology refinements such as automatic tube current modulation, filtered back projections, lowering the tube voltage, and iterative reconstructions as tools for optimizing low and ultra-low dose protocols of CTC. Future perspectives arise from integrating artificial intelligence in computed tomography machines for the screening of CRC.

Colorectal Cancer-Derived CAT1-Positive Extracellular Vesicles Alter Nitric Oxide Metabolism in Endothelial Cells and Promote Angiogenesis

Accumulating scientific evidences strongly support the importance of cancer-derived extracellular vesicles (EV) in organization of tumor microenvironment and metastatic niches, which are also considered as ideal tools for cancer liquid biopsy. To uncover the full scope of proteomic information packaged within EVs secreted directly from human colorectal cancer, we cultured surgically resected viable tissues and obtained tissue-exudative EVs (Te-EV). Our quantitative profiling of 6,307 Te-EV proteins and 8,565 tissue proteins from primary colorectal cancer and adjacent normal mucosa (n = 17) allowed identification of a specific cargo in colorectal cancer-derived Te-EVs, high-affinity cationic amino acid transporter 1 (CAT1, P = 5.0 × 10^-3, fold change = 6.2), in addition to discovery of a new class of EV markers, VPS family proteins. The EV sandwich ELISA confirmed escalation of the EV-CAT1 level in plasma from patients with colorectal cancer compared with healthy donors (n = 119, P = 3.8 × 10^-7). Further metabolomic analysis revealed that CAT1-overexpressed EVs drastically enhanced vascular endothelial cell growth and tubule formation via upregulation of arginine transport and downstream NO metabolic pathway. These findings demonstrate the potency of CAT1 as an EV-based biomarker for colorectal cancer and its functional significance on tumor angiogenesis. IMPLICATIONS: This study provides a proteome-wide compositional dataset for viable colorectal cancer tissue-derived EVs and especially emphasizes importance of EV-CAT1 as a key regulator of angiogenesis.

A risk-stratified approach to colorectal cancer prevention and diagnosis

Population screening and endoscopic surveillance are used widely to prevent the development of and death from colorectal cancer (CRC). However, CRC remains a major cause of cancer mortality and the increasing burden of endoscopic investigations threatens to overwhelm some health services. This Perspective describes the rationale for and approach to improved risk stratification and decision-making for CRC prevention and diagnosis. Limitations of current approaches will be discussed using the UK as an example of the challenges faced by a particular health-care system, followed by discussion of novel risk biomarker utilization. We explore how risk stratification will be advantageous to current health-care providers and users, enabling more efficient use of limited colonoscopy resources. We discuss risk stratification in the setting of population screening as well as the surveillance of high-risk groups and investigation of symptomatic patients. We also address challenges in the development and validation of risk stratification tools and identify key research priorities.

Cancer diagnostic tools to aid decision-making in primary care: mixed-methods systematic reviews and cost-effectiveness analysis

BACKGROUND

Tools based on diagnostic prediction models are available to help general practitioners diagnose cancer. It is unclear whether or not tools expedite diagnosis or affect patient quality of life and/or survival.

OBJECTIVES

The objectives were to evaluate the evidence on the validation, clinical effectiveness, cost-effectiveness, and availability and use of cancer diagnostic tools in primary care.

METHODS

Two systematic reviews were conducted to examine the clinical effectiveness (review 1) and the development, validation and accuracy (review 2) of diagnostic prediction models for aiding general practitioners in cancer diagnosis. Bibliographic searches were conducted on MEDLINE, MEDLINE In-Process, EMBASE, Cochrane Library and Web of Science) in May 2017, with updated searches conducted in November 2018. A decision-analytic model explored the tools' clinical effectiveness and cost-effectiveness in colorectal cancer. The model compared patient outcomes and costs between strategies that included the use of the tools and those that did not, using the NHS perspective. We surveyed 4600 general practitioners in randomly selected UK practices to determine the proportions of general practices and general practitioners with access to, and using, cancer decision support tools. Association between access to these tools and practice-level cancer diagnostic indicators was explored.

RESULTS

Systematic review 1 - five studies, of different design and quality, reporting on three diagnostic tools, were included. We found no evidence that using the tools was associated with better outcomes. Systematic review 2 - 43 studies were included, reporting on prediction models, in various stages of development, for 14 cancer sites (including multiple cancers). Most studies relate to QCancer® (ClinRisk Ltd, Leeds, UK) and risk assessment tools.

DECISION MODEL

In the absence of studies reporting their clinical outcomes, QCancer and risk assessment tools were evaluated against faecal immunochemical testing. A linked data approach was used, which translates diagnostic accuracy into time to diagnosis and treatment, and stage at diagnosis. Given the current lack of evidence, the model showed that the cost-effectiveness of diagnostic tools in colorectal cancer relies on demonstrating patient survival benefits. Sensitivity of faecal immunochemical testing and specificity of QCancer and risk assessment tools in a low-risk population were the key uncertain parameters.

SURVEY

Practitioner- and practice-level response rates were 10.3% (476/4600) and 23.3% (227/975), respectively. Cancer decision support tools were available in 83 out of 227 practices (36.6%, 95% confidence interval 30.3% to 43.1%), and were likely to be used in 38 out of 227 practices (16.7%, 95% confidence interval 12.1% to 22.2%). The mean 2-week-wait referral rate did not differ between practices that do and practices that do not have access to QCancer or risk assessment tools (mean difference of 1.8 referrals per 100,000 referrals, 95% confidence interval -6.7 to 10.3 referrals per 100,000 referrals).

LIMITATIONS

There is little good-quality evidence on the clinical effectiveness and cost-effectiveness of diagnostic tools. Many diagnostic prediction models are limited by a lack of external validation. There are limited data on current UK practice and clinical outcomes of diagnostic strategies, and there is no evidence on the quality-of-life outcomes of diagnostic results. The survey was limited by low response rates.

CONCLUSION

The evidence base on the tools is limited. Research on how general practitioners interact with the tools may help to identify barriers to implementation and uptake, and the potential for clinical effectiveness.

FUTURE WORK

Continued model validation is recommended, especially for risk assessment tools. Assessment of the tools' impact on time to diagnosis and treatment, stage at diagnosis, and health outcomes is also recommended, as is further work to understand how tools are used in general practitioner consultations.

STUDY REGISTRATION

This study is registered as PROSPERO CRD42017068373 and CRD42017068375.

FUNDING

This project was funded by the National Institute for Health Research (NIHR) Health Technology programme and will be published in full in Health Technology Assessment; Vol. 24, No. 66. See the NIHR Journals Library website for further project information.

Adverse Events After Inpatient Colonoscopy in Octogenarians: Results From the National Inpatient Sample (1998-2013)

BACKGROUND AND AIM

Colonoscopy is commonly performed in the elderly who have a higher proportion of lower gastrointestinal (GI) tract disorders. However, few studies have evaluated the safety of colonoscopy specifically in the octogenarian population. The goal of this study is to examine the safety of colonoscopy among octogenarians over a 16-year period. We also examine risk factors associated with morbidity and mortality in octogenarians after inpatient colonoscopy.

MATERIALS AND METHODS

We queried the National Inpatient Sample to identify octogenarians who had a colonoscopy during hospitalization from 1998 to 2013. We examined inpatient GI-related adverse events including colonic perforation, postcolonoscopy bleeding, and splenic injury. We also examined all-cause mortality rates after colonoscopy.

RESULTS

About a quarter of inpatient colonoscopies performed annually were in octogenarians. Of 296,385 colonoscopies included in our study, colon perforation, postcolonoscopy bleeding, and splenic injury occurred in 11, 9, and 0.22 per 1000 colonoscopies, respectively. Overall mortality rate was 2.8%, most (2.5%) dying within 30 days of colonoscopy. After controlling for covariates, those who had colon perforation, postcolonoscopy bleeding, or splenic injury were at a much higher risk of inpatient mortality.

CONCLUSIONS

There seems to be a higher risk of adverse GI-related events after colonoscopy in octogenarians as compared with the general population. Furthermore, occurrence of adverse GI-related events increased the risk of mortality among octogenarians regardless of comorbid status.

Genome-wide Modeling of Polygenic Risk Score in Colorectal Cancer Risk

Accurate colorectal cancer (CRC) risk prediction models are critical for identifying individuals at low and high risk of developing CRC, as they can then be offered targeted screening and interventions to address their risks of developing disease (if they are in a high-risk group) and avoid unnecessary screening and interventions (if they are in a low-risk group). As it is likely that thousands of genetic variants contribute to CRC risk, it is clinically important to investigate whether these genetic variants can be used jointly for CRC risk prediction. In this paper, we derived and compared different approaches to generating predictive polygenic risk scores (PRS) from genome-wide association studies (GWASs) including 55,105 CRC-affected case subjects and 65,079 control subjects of European ancestry. We built the PRS in three ways, using (1) 140 previously identified and validated CRC loci; (2) SNP selection based on linkage disequilibrium (LD) clumping followed by machine-learning approaches; and (3) LDpred, a Bayesian approach for genome-wide risk prediction. We tested the PRS in an independent cohort of 101,987 individuals with 1,699 CRC-affected case subjects. The discriminatory accuracy, calculated by the age- and sex-adjusted area under the receiver operating characteristics curve (AUC), was highest for the LDpred-derived PRS (AUC = 0.654) including nearly 1.2 M genetic variants (the proportion of causal genetic variants for CRC assumed to be 0.003), whereas the PRS of the 140 known variants identified from GWASs had the lowest AUC (AUC = 0.629). Based on the LDpred-derived PRS, we are able to identify 30% of individuals without a family history as having risk for CRC similar to those with a family history of CRC, whereas the PRS based on known GWAS variants identified only top 10% as having a similar relative risk. About 90% of these individuals have no family history and would have been considered average risk under current screening guidelines, but might benefit from earlier screening. The developed PRS offers a way for risk-stratified CRC screening and other targeted interventions.

Cost-effectiveness of surveillance with CT colonography after resection of colorectal cancer

OBJECTIVE

Surveillance following colorectal cancer (CRC) resection uses optical colonoscopy (OC) to detect intraluminal disease and CT to detect extracolonic recurrence. CT colonography (CTC) might be an efficient use of resources in this situation because it allows for intraluminal and extraluminal evaluations with one test.

DESIGN

We developed a simulation model to compare lifetime costs and benefits for a cohort of patients with resected CRC. Standard of care involved annual CT for 3 years and OC for years 1, 4 and every 5 years thereafter. For the CTC-based strategy, we replace CT+OC at year 1 with CTC. Patients with lesions greater than 6 mm detected by CTC underwent OC. Detection of an adenoma 10 mm or larger was followed by OC at 1 year, then every 3 years thereafter. Test characteristics and costs for CTC were derived from a clinical study. Medicare costs were used for cancer care costs as well as alternative test costs. We discounted costs and effects at 3% per year.

RESULTS

For persons with resected stage III CRC, the standard-of-care strategy was more costly (US$293) and effective (2.6 averted CRC cases and 1.1 averted cancer deaths per 1000) than the CTC-based strategy, with an incremental cost-effectiveness ratio of US$55 500 per quality-adjusted life-year gained. Our analysis was most sensitive to the sensitivity of CTC for detecting polyps 10 mm or larger and assumptions about disease progression.

CONCLUSION

In a simulation model, we found that replacing the standard-of-care approach to postdiagnostic surveillance with a CTC-based strategy is not an efficient use of resources in most situations.

Clinical outcomes of laparoscopic versus open surgery for repairing colonoscopic perforation: a multicenter study

PURPOSE

We conducted this study to compare the perioperative outcomes of laparoscopic surgery (LS) vs. open surgery (OS) for repairing colonoscopic perforation, and to evaluate the possible predictors of complications.

METHOD

We reviewed the medical records of patients who underwent surgical repair of colonoscopic perforation by LS or OS between January 2005 and June 2019 at six Hallym University-affiliated hospitals. Multivariable analysis was performed to identify the predictors of postoperative complications.

RESULTS

Of the total 99 patients, 40 underwent OS and 59 underwent LS. The postoperative hospital stay and the time to resuming a soft diet were shorter in the LS group than in the OS group (P = 0.017 and 0.026, respectively). The complication rate and Clavien-Dindo classification were not significantly different between the two groups. Multivariable analysis revealed that an American Society of Anesthesiologists score (ASA) ≥ 3 and switching from non-operative management to surgical treatment were independently associated with complications (P = 0.025 and 0.010, respectively).

CONCLUSION

LS may be a safe alternative to OS for repairing colonoscopic perforation with a shorter postoperative hospital stay and time to resuming a soft diet. Patients with an ASA score ≥ 3 and those with changes to their planned treatment should be monitored carefully to minimize their risk of complications.

Effect of delays in the 2-week-wait cancer referral pathway during the COVID-19 pandemic on cancer survival in the UK: a modelling study

BACKGROUND

During the COVID-19 lockdown, referrals via the 2-week-wait urgent pathway for suspected cancer in England, UK, are reported to have decreased by up to 84%. We aimed to examine the impact of different scenarios of lockdown-accumulated backlog in cancer referrals on cancer survival, and the impact on survival per referred patient due to delayed referral versus risk of death from nosocomial infection with severe acute respiratory syndrome coronavirus 2.

METHODS

In this modelling study, we used age-stratified and stage-stratified 10-year cancer survival estimates for patients in England, UK, for 20 common tumour types diagnosed in 2008-17 at age 30 years and older from Public Health England. We also used data for cancer diagnoses made via the 2-week-wait referral pathway in 2013-16 from the Cancer Waiting Times system from NHS Digital. We applied per-day hazard ratios (HRs) for cancer progression that we generated from observational studies of delay to treatment. We quantified the annual numbers of cancers at stage I-III diagnosed via the 2-week-wait pathway using 2-week-wait age-specific and stage-specific breakdowns. From these numbers, we estimated the aggregate number of lives and life-years lost in England for per-patient delays of 1-6 months in presentation, diagnosis, or cancer treatment, or a combination of these. We assessed three scenarios of a 3-month period of lockdown during which 25%, 50%, and 75% of the normal monthly volumes of symptomatic patients delayed their presentation until after lockdown. Using referral-to-diagnosis conversion rates and COVID-19 case-fatality rates, we also estimated the survival increment per patient referred.

FINDINGS

Across England in 2013-16, an average of 6281 patients with stage I-III cancer were diagnosed via the 2-week-wait pathway per month, of whom 1691 (27%) would be predicted to die within 10 years from their disease. Delays in presentation via the 2-week-wait pathway over a 3-month lockdown period (with an average presentational delay of 2 months per patient) would result in 181 additional lives and 3316 life-years lost as a result of a backlog of referrals of 25%, 361 additional lives and 6632 life-years lost for a 50% backlog of referrals, and 542 additional lives and 9948 life-years lost for a 75% backlog in referrals. Compared with all diagnostics for the backlog being done in month 1 after lockdown, additional capacity across months 1-3 would result in 90 additional lives and 1662 live-years lost due to diagnostic delays for the 25% backlog scenario, 183 additional lives and 3362 life-years lost under the 50% backlog scenario, and 276 additional lives and 5075 life-years lost under the 75% backlog scenario. However, a delay in additional diagnostic capacity with provision spread across months 3-8 after lockdown would result in 401 additional lives and 7332 life-years lost due to diagnostic delays under the 25% backlog scenario, 811 additional lives and 14 873 life-years lost under the 50% backlog scenario, and 1231 additional lives and 22 635 life-years lost under the 75% backlog scenario. A 2-month delay in 2-week-wait investigatory referrals results in an estimated loss of between 0·0 and 0·7 life-years per referred patient, depending on age and tumour type.

INTERPRETATION

Prompt provision of additional capacity to address the backlog of diagnostics will minimise deaths as a result of diagnostic delays that could add to those predicted due to expected presentational delays. Prioritisation of patient groups for whom delay would result in most life-years lost warrants consideration as an option for mitigating the aggregate burden of mortality in patients with cancer.

FUNDING

None.

Risks, time trends, and mortality of colonoscopy-induced perforation in hospitalized patients

BACKGROUND AND AIM

Colonic perforation is a rare complication of colonoscopy and ranges from 0% to 1% in all patients undergoing colonoscopy. The aim of this study was to assess the time trends, risk factors, and mortality associated with colonoscopy-induced perforation (CIP) in hospitalized patients as the data are limited.

METHODS

Data are obtained from the Nationwide Inpatient Sample database to identify hospitalized patients between 2005 and 2014 that had CIP. Various factors like age and gender were assessed for association with CIP, followed by univariate and multivariate regression analyses.

RESULTS

A total of 2 651 109 patients underwent inpatient colonoscopy between 2005 and 2014, and 4567 (0.2%) of the patients had CIP. Overall, incidence of CIP has increased from 2005 to 2014 (0.1% to 0.3%) (P < 0.001). On multivariate analysis, the adjusted odds ratio (OR) for CIP was highest in Caucasian race (OR: 1.49 [1.09, 2.06]), followed by after polypectomy, history of inflammatory bowel disease, end-stage renal disease, and age > 65 years (OR [95% CI] of 1.35 [1.23, 1.47], 1.34 [1.17, 1.53], 1.28 [1.02, 1.62], and 1.21 [1.11, 1.33], respectively) (all P < 0.05). CIP group had 33% less obesity (OR [95% CI]: 0.77 [0.65-0.9], P = 0.002) and 13-fold higher mortality (0.5% vs 8.1%) (P < 0.001) as compared to patients without CIP. The CIP-associated mortality ranged from 2% to 8% and remained stable throughout the study period.

CONCLUSIONS

Our study suggests that the risk of CIP was highest in elderly patients, Caucasians, those with inflammatory bowel disease, end-stage renal disease, and after polypectomy. Recognizing the factors associated with CIP may lead to informed discussion about risks and benefits of inpatient colonoscopy.

Magnetic resonance spectroscopy and its application in colorectal cancer diagnosis and screening: A narrative review

There are several slightly invasive methods to detect colorectal carcinoma (CRC) including colonoscopy and sigmoidoscopy; but there is no noninvasive, accurate screening test. It is recommended to initiate screening at the age of 50 for non-familial CRC. Laboratory tests are routinely suggested if internal observation and imaging are recommended for further evaluation. Spectroscopic-based imaging, such as magnetic resonance spectroscopy (MRS) is an interesting and promising tool with the potential to be an alternative to some minimally invasive procedures, such as biopsy. Accordingly, MRS might be a suitable substitution for invasive methods, such as colonoscopy. This article aimed to review the studies that have evaluated the MRS technique as a screening tool in CRC.

Clinical efficacy of the over-the-scope clip device: A systematic review

BACKGROUND

The over-the-scope clip (OTSC) system has been increasingly utilized as a non-surgical option to endoscopically manage refractory gastrointestinal (GI) hemorrhage, perforations/luminal defects and fistulas. Limited data exist evaluating the efficacy and safety of OTSC.

AIM

To determine the clinical success and adverse event (AE) rates of OTSC across all GI indications.

METHODS

A PubMed search was conducted for eligible articles describing the application of the OTSC system for any indication in the GI tract. Any article or case series reporting data for less than 5 total patients was excluded. The primary outcome was the rate of clinical success. Secondary outcomes included: Technical success rate, OTSC-related AE rate and requirement for surgical intervention despite-OTSC placement. Pooled rates (per-indication and overall) were calculated as the number of patients with the event of interest divided by the total number of patients.

RESULTS

A total of 85 articles met our inclusion criteria (n = 3025 patients). OTSC was successfully deployed in 94.4% of patients (n = 2856/3025). The overall rate of clinical success (all indications) was 78.4% (n = 2371/3025). Per-indication clinical success rates were as follows: (1) 86.0% (1120/1303) for GI hemorrhage; (2) 85.3% (399/468) for perforation; (3) 55.8% (347/622) for fistulae; (4) 72.6% (284/391) for anastomotic leaks; (5) 92.8% (205/221) for defect closure following endoscopic resection (e.g., following endoscopic mucosal resection or endoscopic submucosal dissection); and (6) 80.0% (16/20) for stent fixation. AE's related to the deployment of OTSC were only reported in 64 of 85 studies (n = 1942 patients), with an overall AE rate of 2.1% (n = 40/1942). Salvage surgical intervention was required in 4.7% of patients (n = 143/3025).

CONCLUSION

This systematic review demonstrates that the OTSC system is a safe and effective endoscopic therapy to manage GI hemorrhage, perforations, anastomotic leaks, defects created by endoscopic resections and for stent fixation. Clinical success in fistula management appears limited. Further studies, including randomized controlled trials comparing OTSC with conventional and/or surgical therapies, are needed to determine which indication(s) are the most effective for its use.

Cost-Effectiveness of Colonoscopy-Based Colorectal Cancer Screening in Childhood Cancer Survivors

BACKGROUND

Childhood cancer survivors (CCS) are at increased risk of developing colorectal cancer (CRC) compared to the general population, especially those previously exposed to abdominal or pelvic radiation therapy (APRT). However, the benefits and costs of CRC screening in CCS are unclear. In this study, we evaluated the cost-effectiveness of early-initiated colonoscopy screening in CCS.

METHODS

We adjusted a previously validated model of CRC screening in the US population (MISCAN-Colon) to reflect CRC and other-cause mortality risk in CCS. We evaluated 91 colonoscopy screening strategies varying in screening interval, age to start, and age to stop screening for all CCS combined and for those treated with or without APRT. Primary outcomes were CRC deaths averted (compared to no screening) and incremental cost-effectiveness ratios (ICERs). A willingness-to-pay threshold of $100 000 per life-years gained (LYG) was used to determine the optimal screening strategy.

RESULTS

Compared to no screening, the US Preventive Services Task Force's average risk screening schedule prevented up to 73.2% of CRC deaths in CCS. The optimal strategy of screening every 10 years from age 40 to 60 years averted 79.2% of deaths, with ICER of $67 000/LYG. Among CCS treated with APRT, colonoscopy every 10 years from age 35 to 65 years was optimal (CRC deaths averted: 82.3%; ICER: $92 000/LYG), whereas among those not previously treated with APRT, screening from age 45 to 55 years every 10 years was optimal (CRC deaths averted: 72.7%; ICER: $57 000/LYG).

CONCLUSIONS

Early initiation of colonoscopy screening for CCS is cost-effective, especially among those treated with APRT.