Efficacy of a nationwide screening colonoscopy program for colorectal cancer

Evaluation of a questionnaire to assess the indication for screening colonoscopy for asymptomatic patients

INTRODUCTION

Colorectal cancer is the second most common cause of cancer death worldwide. Screening colonoscopy is a very effective measure to prevent colorectal cancer and can reduce mortality at the population level. However, the participation rates of screening programs are low.To provide easily accessible information on screening colonoscopy and to increase the participation rates of screening programs, we developed a questionnaire for asymptomatic patients based on the German guidelines to assess the indication for screening colonoscopy. We evaluated the questionnaire with reference to the indications given by specialists in gastroenterology.

METHODS

Patients who visited a specialist in gastroenterology in an outpatient clinic of a tertiary hospital for other reasons than a colonoscopy were eligible for the study. A maximum of seven questions to assess the indication for screening colonoscopy were answered by the patients. Afterward, the indication for screening colonoscopy was given or not by a specialist in gastroenterology. The accuracy of the questionnaire was measured in terms of sensitivity, specificity, and predictive values.

RESULTS

In total, 335 patients were included in the analyses, of whom 50 and 285 patients were given and were not given an indication for screening colonoscopy by the specialists, respectively. In 0/50 patients, the questionnaire was false negative and in 8/285 patients false positive. Thus, the questionnaire had a sensitivity of 100% (95% confidence interval: 93-100%), a specificity of 97% (95-99%), a negative predictive value of 100% (99-100%), and a positive predictive value of 86% (75-94%).A subgroup analysis including patients who had never had a colonoscopy (n=109) showed comparable results: sensitivity of 100% (92-100%), specificity of 92% (83-97%), negative predictive value of 100% (94-100%), and positive predictive value of 90% (87-97%).

CONCLUSION

The self-assessment questionnaire for asymptomatic individuals to assess the recommendation for screening colonoscopy is very sensitive and specific compared to a specialist in gastroenterology.The questionnaire can be found at: https://www.interdisziplinaere-endoskopie.mri.tum.de/de/infos-patienten/index.php.

Contributions of early detection and cancer prevention to colorectal cancer mortality reduction by screening colonoscopy: a validated modeling study

BACKGROUND AND AIMS

Screening colonoscopy, recommended every 10 years, reduces mortality from colorectal cancer (CRC) by early detection of prevalent but undiagnosed CRC, as well as by removal of precursor lesions. The aim of this study was to assess the relative contribution of both components to total CRC mortality reduction over time.

METHODS

Using a validated multistate Markov model, we simulated hypothetical cohorts of 100,000 individuals aged 55 to 64 years with and without screening at baseline. Main outcomes included proportions of prevented CRC deaths arising from (asymptomatic) CRC already present at baseline and from newly developed CRC during 15 years of follow-up, and mortality rate ratios of screened versus nonscreened groups over time.

RESULTS

Early detection of prevalent cases accounted for 52%, 30%, and 18% of deaths prevented by screening colonoscopy within 5, 10, and 15 years, respectively. Relative reduction of mortality was estimated to be much larger for mortality from incident cancers than for mortality from cancers that were already present and detected early at screening endoscopy and for total CRC mortality (ie, 88% versus 67% and 79%, respectively, within 10 years from screening).

CONCLUSIONS

Reduction of CRC mortality mainly arises from early detection of prevalent cancers during the early years after screening colonoscopy, but prevention of incident cases accounts for the majority of prevented deaths in the longer run. Prevention of incident cases leads to sustained strong reduction of CRC mortality, possibly warranting an extension of screening intervals.

Issues of informed consent for non-specialists conducting colorectal cancer screenings

The United States is currently facing a physician shortage crisis including a lack of specialist providers. Due to this shortage of specialists, some primary care providers offer colorectal cancer screenings in communities with few gastroenterologists, especially in under-resourced areas such as rural regions of the United States. However, discrepancies in training and procedural outcomes raise concerns regarding informed consent for patients. Because osteopathic physicians play a critical role in addressing the physician shortage in these under-resourced communities, this commentary may be especially useful because they are likely to encounter these ethical complexities in their day-to-day practice.

Risk for colorectal cancer after computed tomography verified acute diverticulitis: A retrospective cohort study with long-term follow-up

BACKGROUND AND OBJECTIVE

Colorectal cancer (CRC) can mimic acute diverticulitis and can thus be misdiagnosed. Therefore, colonic evaluation is recommended after an episode of acute diverticulitis. The aim of this study was to analyze the risk of CRC after computed tomography (CT) verified uncomplicated and complicated acute diverticulitis in short-term and, particularly, long-term follow-up to ensure the feasibility of the primary CT imaging in separating patients with uncomplicated and complicated acute diverticulitis.

METHODS

A retrospective cohort study was conducted in patients with CT-verified acute diverticulitis in 2003-2012. Data on CT findings and colonic evaluations were analyzed. The patients were divided into those with uncomplicated and complicated acute diverticulitis. Patient charts were reviewed 9-18 years after the initial acute diverticulitis episode.

RESULTS

The study population consisted of 270 patients. According to CT scans, 170 (63%) patients had uncomplicated acute diverticulitis and 100 (37%) had complicated acute diverticulitis. Further colonic evaluation was made in 146 (54%) patients. In the whole study population, CRC was found in 7 (2.6%) patients, but CRC was associated with acute diverticulitis in only 4 (1.5%) patients. The short-term risk for CRC was 0.6% (1/170) in uncomplicated acute diverticulitis and 3.0% (3/100) in complicated acute diverticulitis. No additional CRC was found in patients with complicated acute diverticulitis during the long-term follow-up and three cases of CRC found after uncomplicated acute diverticulitis had no observable association with previous diverticulitis.

CONCLUSIONS

In short-term follow-up, the risk of underlying CRC is very low in CT-verified uncomplicated acute diverticulitis but increased in complicated acute diverticulitis. Long-term follow-up revealed no additional CRCs associated with previous acute diverticulitis, indicating that the short-term results remain consistent also in the long run. These long-term results confirm that colonoscopy should be reserved for patients with complicated acute diverticulitis or with persisting or alarming symptoms.

Incidence of colonoscopy-related perforation and risk factors for poor outcomes: 3-year results from a prospective, multicenter registry (with videos)

BACKGROUND AND AIMS

Perforation is a life-threatening adverse event of colonoscopy that often requires hospitalization and surgery. We aimed to prospectively assess the incidence of colonoscopy-related perforation in a multicenter registry and to analyze the clinical factors associated with poor clinical outcomes.

METHODS

This prospective observational study was conducted at six tertiary referral hospitals between 2017 and 2020, and included patients with colonic perforation after colonoscopy. Poor clinical outcomes were defined as mortality, surgery, and prolonged hospitalization (> 13 days). Logistic regression was used to identify factors associated with poor clinical outcomes.

RESULTS

Among 84,673 patients undergoing colonoscopy, 56 had colon perforation (0.66/1000, 95% confidence interval [CI] 0.51-0.86). Perforation occurred in 12 of 63,602 diagnostic colonoscopies (0.19/1000, 95% CI 0.11-0.33) and 44 of 21,071 therapeutic colonoscopies (2.09/1000, 95% CI 1.55-2.81). Of these, 15 (26.8%) patients underwent surgery, and 25 (44.6%) patients had a prolonged hospital stay. One patient (1.8%) died after perforation from a diagnostic colonoscopy. In the multivariate analysis, diagnostic colonoscopy (adjusted odds ratio [aOR] 196.43, p = 0.025) and abdominal rebound tenderness (aOR 17.82, p = 0.012) were independent risk factors for surgical treatment. The location of the sigmoid colon (aOR 18.57, p = 0.048), delayed recognition (aOR 187.71, p = 0.008), and abdominal tenderness (aOR 63.20, p = 0.017) were independent risk factors for prolonged hospitalization.

CONCLUSIONS

This prospective study demonstrated that the incidence of colonoscopy-related perforation was 0.66/1000. The incidence rate was higher in therapeutic colonoscopy, whereas the risk for undergoing surgery was higher in patients undergoing diagnostic colonoscopy. Colonoscopy indication (diagnostic vs. therapeutic), physical signs, the location of the sigmoid perforation, and delayed recognition were independent risk factors for poor clinical outcomes in colonoscopy-related perforation.

A multicentre study assessing the role of routine colonoscopy after acute uncomplicated diverticulitis and the incidence of colorectal cancer diagnosis

PURPOSE

The low rates of colonic malignancy detected on interval colonoscopy for patients diagnosed with diverticulitis have led recent studies to question the utility of the practice. The aim of this study was to assess the detection rate of colorectal cancer on colonoscopy for patients with a first episode of acute uncomplicated diverticulitis across three separate centres in Ireland and the UK.

METHODS

A retrospective review was performed of patients with a first episode of acute, uncomplicated diverticulitis who underwent interval colonoscopy at three separate centres in the UK and Ireland between 2007 and 2019. The follow-up period was one year.

RESULTS

A total of 5485 patients were admitted with acute diverticulitis between the three centres. All patients had CT verified diverticulitis. A 90.8% (n = 4982) underwent subsequent colonic evaluation with colonoscopy. Of these, a histologically proven diagnosis of colorectal carcinoma was made in 1.28% (n = 64).

CONCLUSION

Routine colonoscopy following an episode of acute, uncomplicated diverticulitis may not be necessary in every patient. It may be appropriate to reserve this more invasive investigation for those with higher risk factors for malignancy.

Chemoresistive Nanosensors Employed to Detect Blood Tumor Markers in Patients Affected by Colorectal Cancer in a One-Year Follow Up

Colorectal cancer (CRC) represents 10% of the annual tumor diagnosis and deaths occurring worldwide. Given the lack of specific symptoms, which could determine a late diagnosis, the research for specific CRC biomarkers and for innovative low-invasive methods to detect them is crucial. Therefore, on the basis of previously published results, some volatile organic compounds (VOCs), detectable through gas sensors, resulted in particularly promising CRC biomarkers, making these sensors suitable candidates to be employed in CRC screening devices. A new device was employed here to analyze the exhalations of blood samples collected from CRC-affected patients at different stages of their pre- and post-surgery therapeutic path, in order to assess the sensor’s capability for discriminating among these samples. The stages considered were: the same day of the surgical treatment (T1); before the hospital discharge (T2); after one month and after 10–12 months from surgery (T3 and T4, respectively). This device, equipped with four different sensors based on different metal–oxide mixtures, enabled a distinction between T1 and T4 with a sensitivity and specificity of 93% and 82%, respectively, making it suitable for clinical follow-up protocols, patient health status monitoring and to detect possible post-treatment relapses.

Prevalence of Colorectal Neoplasia 10 or More Years After a Negative Screening Colonoscopy in 120 000 Repeated Screening Colonoscopies

Importance

Screening colonoscopy to prevent and early detect colorectal cancer is recommended to be repeated in 10-year intervals, which goes along with high demands of capacities and costs. Evidence of findings at screening colonoscopies conducted 10 or more years after a negative colonoscopy result is sparse, and it remains unclear whether screening colonoscopy intervals could possibly be prolonged.

Objective

To assess the prevalence of advanced colorectal neoplasms (ADNs) at least 10 years after a negative screening colonoscopy in a very large cohort of repeated screening colonoscopy participants in Germany.

Design, Setting, and Participants

This registry-based cross-sectional study on screening colonoscopy findings reported to the German screening colonoscopy registry during January 2013 to December 2019 included data on screening colonoscopies that were offered to the German general population 55 years or older since 2002; virtually all screening colonoscopies among individuals covered by Statutory Health Insurance (approximately 90% of eligible adults) are reported to the national registry. A total of 120 298 repeat screening colonoscopy participants 65 years or older were identified who had a previous negative screening colonoscopy at least 10 years prior. The findings were compared with all screening colonoscopies conducted at 65 years or older during the same period (1.25 million). The data were analyzed from March to July 2022.

Main Outcomes and Measures

Prevalence of colorectal cancers and ADNs (advanced adenomas and cancers).

Results

Of 120 298 participants, 72 349 (60.1%) were women. Prevalence of ADN was 3.6% and 5.2% among women and men 10 years after a negative screening colonoscopy and gradually increased to 4.9% and 6.6%, respectively, among those who had a negative colonoscopy 14 years or longer prior compared with 7.1% and 11.6% among all screening colonoscopies. Sex-specific and age-specific prevalence of ADNs at repeated colonoscopies conducted 10 or more years after a negative colonoscopy were consistently at least 40% lower among women than among men, lower at younger vs older ages, and much lower than among all screening colonoscopies (standardized prevalence ratios for cancers: 0.22-0.38 among women, 0.15-0.24 among men; standardized prevalence ratios for ADNs: 0.49-0.62 among women, 0.50-0.56 among men).

Conclusions and Relevance

The results of this cross-sectional study suggest that ADN prevalence at screening colonoscopies conducted 10 or more years after a negative screening colonoscopy is low. Extension of the currently recommended 10-year screening intervals may be warranted, especially for female and younger participants without gastrointestinal symptoms.

Making colonoscopy-based screening more efficient: A "gateopener" approach

Screening colonoscopy for early detection and prevention of colorectal cancer (CRC) is mostly used inefficiently. Here, we assessed the potential of an innovative approach to colonoscopy-based screening, by use of a single, low threshold fecal immunochemical test (FIT) as a "gateopener" for screening colonoscopy. Using COSIMO, a validated simulation model, we modeled scenarios including either direct invitation to screening colonoscopy or an alternative approach involving mailing a single ("gateopener") FIT along with an invitation to colonoscopy contingent on a FIT value above a low threshold yielding a 50% positivity rate (ie, every other pretest will be positive). Under plausible assumptions on screening offer adherence, we found that such "gateopener screening" (use of screening colonoscopy contingent on a positive, low threshold gateopener FIT) approximately doubled cancer detection rates vs conventional screening. In those spared from screening colonoscopy due to a negative gateopener FIT pretest, numbers needed to screen were 10-times higher vs those for individuals with a positive FIT, peaking in >2000 and >3800 (hypothetically) needed colonoscopies to detect one case of cancer in men and women, respectively. Gateopener screening resulted in 42%-51% and 59%-65% more prevented CRC cases and deaths, respectively. In summary, by directing colonoscopy capacities to those most likely to benefit, offering screening colonoscopy contingent on a "gateopener" low-threshold FIT would substantially enhance efficiency of colonoscopy screening.

Modeling the Natural History and Screening Effects of Colorectal Cancer Using Both Adenoma and Serrated Neoplasia Pathways: The Development, Calibration, and Validation of a Discrete Event Simulation Model

Background. Existing colorectal cancer (CRC) screening models mostly focus on the adenoma pathway of CRC development, overlooking the serrated neoplasia pathway, which might result in overly optimistic screening predictions. In addition, Bayesian inference methods have not been widely used for model calibration. We aimed to develop a CRC screening model accounting for both pathways, calibrate it with approximate Bayesian computation (ABC) methods, and validate it with large CRC screening trials. Methods. A discrete event simulation (DES) of the CRC natural history (DECAS) was constructed using the adenoma and serrated pathways in R software. The model simulates CRC-related events in a specific birth cohort through various natural history states. Calibration took advantage of 74 prevalence data points from the German screening colonoscopy program of 5.2 million average-risk participants using an ABC method. CRC incidence outputs from DECAS were validated with the German national cancer registry data; screening effects were validated using 17-y data from the UK Flexible Sigmoidoscopy Screening sigmoidoscopy trial and a German screening colonoscopy cohort study. Results. The Bayesian calibration rendered 1,000 sets of posterior parameter samples. With the calibrated parameters, the observed age- and sex-specific CRC prevalences from the German registries were within the 95% DECAS-predicted intervals. Regarding screening effects, DECAS predicted a 41% (95% intervals 30%-51%) and 62% (95% intervals 55%-68%) reduction in 17-y cumulative CRC mortality for a single screening sigmoidoscopy and colonoscopy, respectively, falling within 95% confidence intervals reported in the 2 clinical studies used for validation. Conclusions. We presented DECAS, the first Bayesian-calibrated DES model for CRC natural history and screening, accounting for 2 CRC tumorigenesis pathways. The validated model can serve as a valid tool to evaluate the (cost-)effectiveness of CRC screening strategies.

Highlights

This article presents a new discrete event simulation model, DECAS, which models both adenoma-carcinoma and serrated neoplasia pathways for colorectal cancer (CRC) development and CRC screening effects.DECAS is calibrated based on a Bayesian inference method using the data from German screening colonoscopy program, which consists of more than 5 million first-time average-risk participants aged 55 years and older in 2003 to 2014.DECAS is flexible for evaluating various CRC screening strategies and can differentiate screening effects in different parts of the colon.DECAS is validated with large screening sigmoidoscopy and colonoscopy clinical study data and can be further used to evaluate the (cost-)effectiveness of German colorectal cancer screening strategies.

Cost-effectiveness analysis of a community-based colorectal cancer screening program in Shanghai, China

Background

Since 2011, through the Community-Based Colorectal Cancer Screening Program in Shanghai, China (SHcsp), residents aged >50 years were offered initial colorectal cancer screening using the fecal immunochemical test (FIT) and risk assessment questionnaire (RAQ) for free. Colonoscopy was then recommended for positive results.

Objective

To evaluate the cost-effectiveness of the Community-Based Colorectal Cancer Screening Program in Shanghai, China from the payer perspective.

Methods

This analysis estimated the long-term cost and effectiveness of the 2014-2016 SHcsp based on real-world follow-up data from the SHcsp database, Shanghai Cancer Registry System, vital statistics from Shanghai Municipal Center for Disease Control and Prevention and inpatient CRC expense data from hospitals. A decision-tree model and Markov model were constructed to simulate the 25-year health outcomes. The screening branch was the cohort with a definite diagnosis of adenoma, advanced adenoma, and CRC. The other branch was residents who were neither screened nor treated until CRC symptoms appeared. A payer prospective was adopted to measure direct costs and effectiveness by life years (LYs) and quality-adjusted life years (QALYs) gained, and were discounted by 3%. Stimulation robustness was tested by one-way sensitivity analysis.

Results

Of 1,097,656 residents, 13,250 were diagnosed with adenoma, advanced adenoma, or CRC. Assuming those had not been found through screening, SHcsp resulted in 1,570.1 LYs and 13,984.3 QALYs gained at an extra cost of USD9.96 million. The incremental cost-effectiveness ratio (ICER) was USD6,342.02 per LY and USD712.08 per QALY obtained, far below the threshold of USD59,598 of three-time GDP per capita in Shanghai.

Conclusion

The SHcsp was cost-effective than no screening strategy. The results were generalisable to the Chinese population for mass CRC screening.

COVID-19 and inequities in colorectal and cervical cancer screening and diagnosis in Washington State

INTRODUCTION

Studies have shown that cancer screenings dropped dramatically following the onset of the coronavirus diseases 2019 (COVID-19) pandemic. In this study, we examined differences in rates of cervical and colorectal cancer (CRC) screening and diagnosis indicators before and during the first year of the COVID-19 pandemic.

METHODOLOGY

We used retrospective data from a large healthcare system in Washington State. Targeted screening data included completed cancer screenings for both CRC (colonoscopy) and cervical cancer (Papanicolaou test (Pap test)). We analyzed and compared the rate of uptake of colorectal (colonoscopies) and cervical cancer (Pap) screenings done pre-COVID-19 (April 1, 2019-March 31, 2020) and during the pandemic (April 1, 2020-March 31, 2021).

RESULTS

A total of 26,081 (12.7%) patients underwent colonoscopies in the pre-COVID-19 period, compared to only 15,708 (7.4%) patients during the pandemic, showing a 39.8% decrease. A total of 238 patients were referred to medical oncology for CRC compared to only 155 patients during the first year of the pandemic, a reduction of 34%. In the pre-COVID-19 period, 22,395 (10.7%) women were administered PAP tests compared to 20,455 (9.6%) women during the pandemic, for a 7.4% reduction. period 1780 women were referred to colposcopy, compared to only 1680 patients during the pandemic, for a 4.3% reduction.

CONCLUSION

Interruption in screening and subsequent delay in diagnosis during the pandemic will likely lead to later-stage diagnoses for both CRC and cervical cancer, which is known to result in decreased survival.

IMPACT

The results emphasize the need to prioritize cancer screening, particularly for those at higher risk.

Findings from the first colorectal cancer screening among 103 542 individuals in Vietnam with systematic review of colorectal cancer screening programs in Asia-Pacific region

BACKGROUND

Colorectal cancer is a leading cancer incidence and cause of death worldwide and in Vietnam. Although screening is considered an effective measure to prevent and control colorectal cancer, there is no such effort in Vietnam.

METHODS

Between 01 January 2018 and 31 October 2019, a population-based colorectal cancer screening program was conducted in Hanoi, Vietnam. A health advocacy campaign and follow-up phone calls were used to enroll residents aged ≥40 years old to complete an immunochemical-fecal occult blood testing. Positive immunochemical-fecal occult blood testing was followed by a colonoscopy. We also conducted a systematic review of the colorectal cancer screening programs in the Asia-Pacific region that used similar approach by searching Ovid Medline and PubMed databases.

RESULTS

During study period, 103 542 individuals among 672 742 eligible residents attended the screening of whom 81.5% participants finished immunochemical-fecal occult blood testing test and the positive rate was 6.1%. The coverage rate for immunochemical-fecal occult blood testing test was 11.9%. Among 2278 individuals who underwent colonoscopy, 3.5% were histologically diagnosed with cancer, 17.8% with advanced adenomas, and 23.1% with non-advanced adenomas. Males had significantly higher detection rate of advanced adenomas, cancer or ≥ two polyps/tumor than females (P < 0.0001). The systematic review showed that in two-step modality (i.e. immunochemical-fecal occult blood testing/fecal immunochemical test and colonoscopy), the test positive was from 4.1 to 10.6%. Once colonoscopy was performed subsequently, the rate of cancer among positive participants was from 1.7 to 16.4% and that of advanced adenomas was from 7.1 to 23.1%.

CONCLUSION

We showed that the two-step modality is a promising strategy for colorectal cancer screening in Vietnam that might apply to similar settings with limited resources.

Continuous monitoring of colonoscopy performance in the Netherlands: first results of a nationwide registry

BACKGROUND

To optimize colonoscopy quality, several performance measures have been developed. These are usually assessed without distinction between the indications for colonoscopy. This study aimed to assess the feasibility of linking two national registries (one for colonoscopy and one for adverse events of gastrointestinal endoscopies in the Netherlands), and to describe the results of colonoscopy quality per indication.

METHODS

This retrospective study was conducted with prospectively collected data of the Dutch Gastrointestinal Endoscopy Audit (DGEA) and the Dutch Registration of Complications in Endoscopy (DRCE). Data between 01-01-2016 and 01-01-2019 were analyzed. To calculate adverse event rates, data were linked at the level of endoscopy service.

RESULTS

During the 3-year study period, 266 981 colonoscopies were recorded in DGEA. Of all indications, cecal intubation rate was highest in fecal immunochemical test (FIT)-positive screening colonoscopies (97.1 %), followed by surveillance (93.2 %), diagnostic (90.7 %), and therapeutic colonoscopies (83.1 %). The highest rate of adequate bowel preparation was observed in FIT-positive screening colonoscopies (97.1 %). A total of 1540 colonoscopy-related adverse events occurred (0.58 % of all colonoscopies). Bleeding and perforation and rates were highest for therapeutic (1.56 % and 0.51 %, respectively) and FIT-positive screening (0.72 % and 0.06 %, respectively) colonoscopies. The colonoscopy-related mortality was 0.006 %.

CONCLUSION

This study describes the first results of the Dutch national colonoscopy registry, which was successfully linked to data from the national registry for adverse events of gastrointestinal endoscopies. In this large dataset, performance varied between indications. Our results emphasize the importance of defining benchmarks per indication in future guidelines.

Correlation of Repeat Measurements of 27 Candidate Protein Markers for Colorectal Cancer Screening Taken Three Years and Multiple Freeze-Thaw Cycles Apart

In recent years the blood proteome has been increasingly researched for biomarkers for early detection of colorectal cancer (CRC). Blood samples from screening studies are often subject to preanalytical variability and repeated freeze−thaw cycles. We aimed to assess the correlation of repeat measurements of 27 candidate protein markers for CRC screening taken three years and multiple freeze−thaw cycles apart. The concentrations of 27 protein markers were measured in plasma samples of 39 newly detected CRC cases from a cohort of 9245 participants of screening colonoscopies. The proteins were measured using proximity extension assays (PEA) carried out on the same set of samples twice, three years apart, with an average of three freeze−thaw cycles in between the two measurements. Pearson’s product moment correlation coefficients were calculated. Correlation coefficients ranged from +0.43 to +0.97, with a median of 0.67 and an interquartile range of +0.58 to +0.84, with all p-values of correlation being <0.01 (<0.0005 for 22 proteins, <0.001 for 4 proteins). Repeat measurements of the 27 protein biomarkers for CRC screening performed three years later, and on average three freeze−thaw cycles apart, showed moderate to high levels of correlation. Apart from the effects of freeze−thaw cycles, slightly different preprocessing performed on the data may have contributed to recorded differences between measurements.

Cancer in a polyp of the large intestine - an interdisciplinary decision problem

Large intestine polyps are commonly found during colonoscopies. Pedunculated colon polyps can be totally removed using an endoscopic invasive technique. A problem arises when the pendulated polyp contains cancerous infiltration. The aim of the article was a presentation of the clinical decision process concerned with the presence of cancer invasion tissue within colorectal polyps. Review of literature source and presentation of histological sample photography. A correct interpretation of the pathomorphological protocol is crucial for the therapeutic decision, which should be consistent with the actual recommendations of gastroenterological societies. Local treatment is considered as complete when the adenocarcinoma is well or moderately differentiated without any microinvasion of blood and lymphatic vessels and the resection margin is more than 1 mm from the cancer tissue infiltration. In the contemporary clinical practice patients with a colon polyp require rational clinical decisions, which are based on the actual recommendations.

Attributes Characterizing Colorectal Cancer Screening Tests That Influence Preferences of Individuals Eligible for Screening in Germany: A Qualitative Study

PURPOSE

This qualitative study is part of the SIGMO study, which evaluates general populations' preferences for colorectal cancer (CRC) screening in Germany using a discrete choice experiment. Attribute identification and selection are essential in the construction of choice tasks and should be evidence-based ensuring that attributes are relevant to potential beneficiaries and contribute to overall utility. Therefore, this qualitative study aims to identify relevant attributes characterizing CRC screening tests from the perspective of those eligible for screening in Germany.

PATIENTS AND METHODS

Individuals aged 50 to 60 were purposively selected. A questioning route was developed and piloted. Four focus groups (FG) (n=20) were conducted (November 2019) with two moderators and one observer each. FGs were audio recorded, transcribed, and analyzed using qualitative content analysis. Attributes were deductively assigned based on a priori identified attribute categories, and inductively derived.

RESULTS

Across FGs, 24 attributes (n=293 codes) were discussed, five of which (sedation, inability to work, transportation home, predictive values, waiting time for screening colonoscopy) were inductively derived (n=76 codes). Four attributes identified a priori were not addressed in any FG. The most frequently discussed attribute category was procedural characteristics, followed by measures of screening test validity, benefits, harms, and structural characteristics of health care. The most commonly addressed attributes were preprocedural bowel cleansing, kind of procedure, and predictive values.

CONCLUSION

Newly identified attributes characterizing CRC screening tests from an individual's perspective, and a priori identified attributes not addressed by any FG stress the added value of qualitative research and thereby the importance of applying a mix of methods in identifying and selecting attributes for the construction of choice tasks. This study meets the requirements for a transparent and detailed presentation of the qualitative methods used in this process, which has rarely been the case before.

Optical diagnosis of colorectal polyps using novel blue light imaging classification among trainee endoscopists

BACKGROUND

Blue light imaging (BLI) has been shown to improve the characterization of colorectal polyps among the endoscopy experts. We aimed to determine if this technology could be taught to endoscopy trainees while maintaining high accuracy and interobserver agreement.

METHODS

Twenty-one gastroenterology trainees (fellows) from two academic institutions participated in this prospective study. Each trainee completed a web-based learning comprising four modules: pre-test, didactic videos explaining the BLI Adenoma Serrated International Classification (BASIC), interactive examples, and post-test assessment. The pre- and post-test modules consisted of reviewing video images of colon polyps in high definition white light imaging and BLI and then applying the BASIC classification to determine if the polyps were likely to be adenomatous. Confidence in adenoma identification (rated '1' to '5'), accuracy in polyp (adenoma vs. non-adenoma) identification, and agreement in characterization per BASIC criteria were derived.

RESULTS

Trainee accuracy in the adenoma diagnosis improved from 74.7% (pre-test) to 85.4% (post-test) (P < 0.01). There was a trend towards higher accuracy in polyp characterization with subsequent years of training (1st year fellows 77.4%, 2nd year 88.5%, and final year 94.0%) with consistent improvements after the e-learning across years of trainees. Overall, trainees were able to identify adenoma with a high sensitivity of 86.9%, specificity 83.9%, positive predictive value of 84.4%, and negative predictive value of 86.5%. However, their interobserver agreement in adenoma diagnosis was moderate (k = 0.52).

CONCLUSION

The novel BLI classification can be easily taught to gastroenterology trainees using an online module and accuracy improves with years of training reaching >90% for colorectal polyp characterization.

Colonoscopy may be weak link in organised colorectal cancer screening programme with faecal immunochemical test

OBJECTIVE

To evaluate the quality of colonoscopies performed after a positive faecal immunochemical test in the French colorectal cancer screening programme.

METHODS

Retrospective analysis of all colonoscopies performed between 2015 and 2019 after a positive quantitative faecal immunochemical test in the population-based colorectal cancer screening programme organised in Alsace, part of the French programme. The following indicators were evaluated: annual colonoscopy volume, caecal intubation rate, adenoma detection rate, proximal serrated lesion detection rate and proportion of patients referred directly to surgery for benign polyp management. Endoscopists who performed <30 faecal immunochemical test positive colonoscopies were non-assessable.

RESULTS

Overall, 13,455 faecal immunochemical test-positive colonoscopies performed by 116 community gastroenterologists were included, 13,067 of them by 80 assessable endoscopists. The overall caecal intubation, adenoma detection and proximal serrated lesion detection rates were 97.9%, 57.6% and 7.6%, respectively. They were <90%, <45% and <1% for 1.3%, 12.5% and 6.3% of the endoscopists, respectively. Overall, 1028 (7.9%) individuals were examined by 13 low-performing endoscopists and 328 (2.4%) individuals by 33 low-volume non-assessable endoscopists. Among 9133 individuals harbouring polyps, 155 (1.7%) had unwarranted surgery for a benign polyp. Overall, 1487 individuals (11.1%; 95% confidence interval 10.5-11.6) were not given the best possible chances, whereas 5545 individuals (41.2%; 95% confidence interval 40.4-42.0) were offered the best possible chances by 37 endoscopists.

CONCLUSIONS

At programme level, the key performance indicators evaluated largely exceeded the target standards. At individual level, at least one in nine individuals was not given the best possible chances during faecal immunochemical test-positive colonoscopies by a minority of poor-performing and/or low-volume endoscopists.

Significant decrease of the pathological stage I rectal carcinoma in the era of neoadjuvant therapy-A matter of concern

BACKGROUND

Neoadjuvant treatment (nTx) for rectal cancer is commonly reserved for UICC stages II/III. Patients with stage I tumours (T1-2N0M0) are not candidates for nTx. The accuracy of treatment allocation depends on the precision of clinical staging, which is liable to understaging and overstaging. The study aimed at exploring changes in the proportion of stage pI patients with the introduction of nTx over a 26-year period.

MATERIALS AND METHODS

All consecutive patients with histologically proven rectal cancer excluding carcinoma in situ were retrieved from a prospective database of our colorectal unit. Time periods were defined as per the use of nTx: baseline phase 1994-1997; implementation phase 1998-2005 and guideline phase 2006-2019. Trends over time regarding proportion of applied nTx and stage pI tumours were investigated.

RESULTS

Overall, 1468 patients met the inclusion criteria. There were no major differences in patients' characteristics, especially proportion of synchronous metastases (stage IV) over time. nTx was applied to 1.2% of patients without metastases in the baseline phase, to 29.6% in the implementation phase, and to 59.6% in the guideline phase (p < 0.001). Corresponding proportions for patients with stage pI were 31.0%, 26.3% and 14.2%, respectively (p < 0.001).

CONCLUSION

With a stable proportion of stage IV carcinomas indicating no major changes in the patient cohorts, we could document a significant decrease of stage pI patients with increasing use of nTx. This trend clearly signals overtreatment caused by clinical T- and N-staging. More precise criteria are needed to better select patients with rectal cancer for nTx.

Liquid Biopsy-Based Colorectal Cancer Screening via Surface Markers of Circulating Tumor Cells

Colorectal cancer (CRC) is ranked second for cancer-related deaths worldwide with approximately half of the patients being diagnosed at the late stages. The untimely detection of CRC results in advancement to the metastatic stage and nearly 90% of cancer-related deaths. The early detection of CRC is crucial to decrease its overall incidence and mortality rates. The recent introduction of circulating tumor cells (CTCs) has enabled a less invasive sampling method from liquid biopsies, besides revealing key information toward CRC metastasis. The current gold standard for CTC identification is the CellSearch® system (Veridex). This first-generation instrumentation relies on a single cell surface marker (CSM) to capture and count CTCs. Detection of CTCs allows the identification of patients at risk for metastasis, whereas CTC enumeration could improve risk assessment, monitoring of systemic therapy, and detection of therapy resistance in advanced metastatic CRC. In this review, we compared the pros and cons between single CSM-based CTC enrichment techniques and multi-marker-based systems. We also highlighted the challenges faced in the routine implementation of CSM-dependent CTC detection methods in CRC screening, prediction, prognosis, disease monitoring, and therapy selection toward precision medicine, as well as the dwelling on post-CTC analysis and characterization methods.

Prevalence of Advanced Colorectal Neoplasia in Veterans: Effects of Age, Sex, and Race/Ethnicity

GOAL

We sought to quantify the independent effects of age, sex, and race/ethnicity on risk of colorectal cancer (CRC) and advanced neoplasia (AN) in Veterans.

STUDY

We conducted a retrospective, cross-sectional study of Veterans aged 40 to 80 years who had diagnostic or screening colonoscopy between 2002 and 2009 from 1 of 14 Veterans Affairs Medical Centers. Natural language processing identified the most advanced finding and location (proximal, distal). Logistic regression was used to examine the adjusted, independent effects of age, sex, and race, both overall and in screening and diagnostic subgroups.

RESULTS

Among 90,598 Veterans [mean (SD) age 61.7 (9.4) y, 5.2% (n=4673) were women], CRC and AN prevalence was 1.3% (n=1171) and 8.9% (n=8081), respectively. Adjusted CRC risk was higher for diagnostic versus screening colonoscopy [odds ratio (OR)=3.79; 95% confidence interval (CI), 3.19-4.50], increased with age, was numerically (but not statistically) higher for men overall (OR=1.53; 95% CI, 0.97-2.39) and in the screening subgroup (OR=2.24; 95% CI, 0.71-7.05), and was higher overall for Blacks and Hispanics, but not in screening. AN prevalence increased with age, and was present in 9.2% of men and 3.9% of women [adjusted OR=1.90; 95% CI, 1.60-2.25]. AN risk was 11% higher in Blacks than in Whites overall (OR=1.11; 95% CI, 1.04-1.20), was no different in screening, and was lower in Hispanics (OR=0.74; 95% CI, 0.55-0.98). Women had more proximal CRC (63% vs. 39% for men; P=0.03), but there was no difference in proximal AN (38.3% for both genders).

CONCLUSIONS

Age and race were associated with AN and CRC prevalence. Blacks had a higher overall prevalence of both CRC and AN, but not among screenings. Men had increased risk for AN, while women had a higher proportion of proximal CRC. These findings may be used to tailor when and how Veterans are screened for CRC.

Complications of colonoscopy in Japan: An analysis using large-scale health insurance claims data

BACKGROUND AND AIM

In Japan, screening colonoscopy for colorectal cancer is expected to reduce colorectal cancer mortality, although its complication rate has not been sufficiently examined. The aim of this study is to analyze severe complications due to colonoscopy.

METHODS

As a study population, we retrospectively used commercially anonymized health insurance claims data covering 5.71 million patients from January 2005 to August 2018. We extracted patients who received colonoscopy with lesions resection or without treatment. Main outcomes were rates of hemorrhage, perforation, fatal events, and their risk factors.

RESULTS

Among 341 852 colonoscopy without treatment in 260 128 patients (mean age: 49.6 ± 11.7 years), the rates of hemorrhage, perforation, and fatal events were 0.0059% (95% confidence interval [CI] 0.0031-0.0085), 0.0032% (95% CI 0.0011-0.0052), and 0.00029% (95% CI 0-0.0012), respectively. Regarding hemorrhage, compared with the rate for patients <50 years old (0.0050%), the rates for those 50-59, 60-69, and ≥70 years old were 0.0095% (P = 0.17), 0.0031% (P = 0.17), and 0%, respectively. Regarding perforation, compared with patients <50 years old (0.0056%), the rates for those 50-59, 60-69, and ≥70 years old were 0%, 0.0015% (P = 0.99), and 0.0102% (P = 0.99), respectively. A multivariate analysis for risk factors showed no significant findings for hemorrhage and perforation without treatment. Among 123 087 colonoscopy with lesions resection in 102 058 patients (mean age: 53.7 ± 9.3 years), the rates of hemorrhage, perforation, and fatal events were 0.136% (95% CI 0.1157-0.1572), 0.033% (95% CI 0.0228-0.0437), and 0.00081% (95% CI 0-0.0035), respectively.

CONCLUSIONS

The analysis using health insurance claims data demonstrated the safety of colonoscopy.

[Prevention of gastrointestinal cancer]

Throughout the past decades, considerable progress has been made in the (early) diagnosis and treatment of gastrointestinal cancers. However, the prognosis for advanced stages of gastrointestinal tumors remains limited for many patients and approximately one third of all tumor patients die as a result of gastrointestinal tumors. The prevention and early detection of gastrointestinal tumors is therefore of great importance.For this reason, we summarize the current state of knowledge and recommendations for the primary, secondary and tertiary prevention of esophageal, stomach, pancreas, liver and colorectal cancer in the following.

Cancer-Associated Mutations in Normal Colorectal Mucosa Adjacent to Sporadic Neoplasia

INTRODUCTION:

Colorectal cancer arises in a multistep process of carcinogenesis from normal mucosa. The earliest precursor might be a morphologically inconspicuous precancerous field, harboring cancer-associated mutations.

METHODS:

We systematically analyzed genetic alterations in 77 tissue samples from 30 patients with sporadic colorectal neoplasms (18 large adenomas and 12 adenocarcinomas) and matched adjacent normal mucosa (N = 30), as well as normal rectal tissue (N = 17). We profiled mutations associated with colorectal cancer by targeted sequencing of 46 genetic loci using 157 custom amplicons and a median depth of 42,655 reads per loci.

RESULTS:

Multiple mutations were found in colorectal neoplasms, most frequently in APC, KRAS, and TP53. In a subgroup of 11 of 30 patients, alterations were also detected in non-neoplastic mucosa. These mutations were divergent from those in matched neoplasms. The total alteration count and the allele frequency of mutations were higher in neoplasms compared with those in adjacent tissues. We found that younger patients (≤70 years) are less likely affected by mutations in non-neoplastic mucosa than older patients (>70 years, P = 0.013), although no association was found for other variables, including type, location and differentiation of neoplasia, and previous history of polyps.

DISCUSSION:

Our data show that cancer-associated mutations can be found in non-neoplastic tissues in a subgroup of patients with colorectal neoplasms. Further studies are needed to specify the risk of occurrence and recurrence of neoplasia in this patient population.

Prevalence of colorectal cancer and its precursor lesions in symptomatic patients under 55 years of age undergoing total colonoscopy: results of a large retrospective, multicenter, controlled endoscopy study

PURPOSE

Colorectal cancer (CRC) is the second most common cancer in Germany. Around 60,000 people were diagnosed CRC in 2016 in Germany. Since 2019, screening colonoscopies are offered in Germany for men by the age of 50 and for women by the age of 55. It is recently discussed if women should also undergo a screening colonoscopy by the age of 50 and if there are any predictors for getting CRC.

METHODS

Colonoscopies of 1553 symptomatic patients younger than 55 years were compared with colonoscopies of 1075 symptomatic patients older than 55 years. We analyzed if there are any significant differences between those two groups in the prevalence of CRC and its precursor lesions or between symptomatic men and women. We evaluated if there is a correlation between abdominal symptoms and the prevalence of CRC.

RESULTS

In 164/1553 symptomatic patients, 194 (12.5%) polyps were detected. In total, six colorectal carcinomas (0.4%) were detected. There were no significant differences between men and women. In symptomatic patients ≥ 55 years, significantly more polyps were found (p<0.0001; 26.6% vs. 12.5%). Totally, 286 polyps (26.6%) were removed in 1075 symptomatic patients older than 55 years. Anorectal bleeding was the only abdominal symptom being a significant indicator for the prevalence of the occurrence of colon and rectum cancer in both groups (p=0.03, OR=2.73 95%-CI [1.11;6.70]), but with only low sensitivity (44%).

CONCLUSION

Due to no significant differences in men and women, we recommend screening colonoscopies also for women by the age of 50.

Early detection of duodenal cancer by upper gastrointestinal-endoscopy in Lynch syndrome

Small bowel cancer (SBC) is the malignancy with the highest standardized incidence ratio in Lynch syndrome (LS) patients. Of all SBCs, about 50% are duodenal cancers (DCs), therefore being accessible by esophago-gastro-duodenoscopy (EGD) for surveillance. We asked whether early detection of DC is possible for LS patients undergoing surveillance by EGD and if surveillance should be limited to specific subgroups. Data for LS patients with DC were retrieved from the registry of the German Consortium for Familial Intestinal Cancer. Patients undergoing active surveillance by EGDs (surveillance group) were compared to those who did not (nonsurveillance group) regarding tumor stage at diagnosis. Union for International Cancer Control stages I-IIA were defined as early stage disease and IIB-IV as advanced stage disease. Statistical analysis was performed using Fisher's exact test. Among 2015 patients with pathogenic variants in any mismatch-repair-gene, 47 patients with 49 DCs were identified. In 10% of cases, patients were under 35 years at diagnosis; family and personal tumor history did not correlate with DC diagnosis. Pathogenic germline variants in MSH6, PMS2 or EPCAM were present in 10% of patients. Statistical analysis could be performed on 13 DC patients in the surveillance group and 14 in the nonsurveillance group. Early detection was possible for 71% of patients in the surveillance group and 29% of patients in the nonsurveillance group (P = .021). Early detection of DC by EGD in LS patients is feasible regardless of family history, mutational status and should start no later than 25 years of age.

Impact of the National Endoscopy Database (NED) on colonoscopy withdrawal time: a tertiary centre experience

OBJECTIVE

Colonoscopy withdrawal time (CWT) is a key performance indicator affecting polyp detection rate (PDR) and adenoma detection rate (ADR). However, studies have shown wide variation in CWT and ADR between different endoscopists. The National Endoscopy Database (NED) was implemented to enable quality assurance in all endoscopy units across the UK and also to reduce variation in practice. We aimed to assess whether CWT changed since the introduction of NED and whether CWT affected PDR.

METHODS

We used NED to retrospectively collect data regarding CWT and PDR of 25 endoscopists who performed (n=4459 colonoscopies) in the four quarters of 2019. We then compared this data to their performance in 2016, before using NED (n=4324 colonoscopies).

RESULTS

Mean CWT increased from 7.66 min in 2016 to 9.25 min in 2019 (p=0.0001). Mean PDR in the two periods was 29.9% and 28.3% (p=0.64). 72% of endoscopists (18/25) had CWT>6 min in 2016 versus 100% (25/25) in 2019, the longer CWT in 2019 positively correlated with the PDR (r=0.50, p=0.01). Gastroenterology consultants and trainee endoscopists had longer CWT compared with colorectal surgeons both before and after using NED.

CONCLUSION

NED usage increased withdrawal times in colonoscopy. Longer withdrawal times were associated with higher PDR. A national colonoscopy audit using data from NED is required to evaluate whether wide variations in practice across endoscopy units in the UK still exist and to ensure minimum colonoscopy quality standards are achieved.

Endoscopic techniques to reduce recurrence rates after colorectal EMR: systematic review and meta-analysis

Background

Colorectal endoscopic mucosal resection (EMR) is an effective, safe, and minimally invasive treatment for large lateral spreading and sessile polyps. The reported high recurrence rate of approximately 20% is however one of the major drawbacks. Several endoscopic interventions have been suggested to reduce recurrence rates. We conducted a systematic review and meta-analysis to assess the efficacy of endoscopic interventions targeting the EMR margin to reduce recurrence rates.

Methods

We searched in PubMed and Ovid for studies comparing recurrence rates after interventions targeting the EMR margin with standard EMR. The primary outcome was the recurrence rate at the first surveillance colonoscopy (SC1) assessed histologically or macroscopically. For the meta-analysis, risk ratios (RRs) were calculated and pooled using a random effects model. The secondary outcome was post-procedural complication rates.

Results

Six studies with a total of 1335 lesions were included in the meta-analysis. The techniques performed in the intervention group targeting the resection margin were argon plasma coagulation, snare tip soft coagulation, extended EMR, and precutting EMR. The interventions reduced the adenoma recurrence rate with more than 50%, resulting in a pooled RR of 0.37 (95% CI 0.18, 0.76) comparing the intervention group with the control groups. Overall post-procedural complication rates did not increase significantly in the intervention arm (RR 1.30; 95% CI 0.65, 2.58).

Conclusion

Interventions targeting the EMR margin decrease recurrence rates and may not result in more complications.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00464-021-08574-z.

Derivation and validation of a predictive model for advanced colorectal neoplasia in asymptomatic adults

OBJECTIVE

Knowing risk for advanced colorectal neoplasia (AN) could help patients and providers choose among screening tests, improving screening efficiency and uptake. We created a risk prediction model for AN to help decide which test might be preferred, a use not considered for existing models.

DESIGN

Average-risk 50-to-80-year olds undergoing first-time screening colonoscopy were recruited from endoscopy units in Indiana. We measured sociodemographic and physical features, medical and family history and lifestyle factors and linked these to the most advanced finding. We derived a risk equation on two-thirds of the sample and assigned points to each variable to create a risk score. Scores with comparable risks were collapsed into risk categories. The model and score were tested on the remaining sample.

RESULTS

Among 3025 subjects in the derivation set (mean age 57.3 (6.5) years; 52% women), AN prevalence was 9.4%. The 13-variable model (c-statistic=0.77) produced three risk groups with AN risks of 1.5% (95% CI 0.72% to 2.74%), 7.06% (CI 5.89% to 8.38%) and 27.26% (CI 23.47% to 31.30%) in low-risk, intermediate-risk and high-risk groups (p value <0.001), containing 23%, 59% and 18% of subjects, respectively. In the validation set of 1475 subjects (AN prevalence of 8.4%), model performance was comparable (c-statistic=0.78), with AN risks of 2.73% (CI 1.25% to 5.11%), 5.57% (CI 4.12% to 7.34%) and 25.79% (CI 20.51% to 31.66%) in low-risk, intermediate-risk and high-risk subgroups, respectively (p<0.001), containing proportions of 23%, 59% and 18%.

CONCLUSION

Among average-risk persons, this model estimates AN risk with high discrimination, identifying a lower risk subgroup that may be screened non-invasively and a higher risk subgroup for which colonoscopy may be preferred. The model could help guide patient-provider discussions of screening options, may increase screening adherence and conserve colonoscopy resources.

Screening for Colorectal Cancer: Updated Evidence Report and Systematic Review for the US Preventive Services Task Force

IMPORTANCE

Colorectal cancer (CRC) remains a significant cause of morbidity and mortality in the US.

OBJECTIVE

To systematically review the effectiveness, test accuracy, and harms of screening for CRC to inform the US Preventive Services Task Force.

DATA SOURCES

MEDLINE, PubMed, and the Cochrane Central Register of Controlled Trials for relevant studies published from January 1, 2015, to December 4, 2019; surveillance through March 26, 2021.

STUDY SELECTION

English-language studies conducted in asymptomatic populations at general risk of CRC.

DATA EXTRACTION AND SYNTHESIS

Two reviewers independently appraised the articles and extracted relevant study data from fair- or good-quality studies. Random-effects meta-analyses were conducted.

MAIN OUTCOMES AND MEASURES

Colorectal cancer incidence and mortality, test accuracy in detecting cancers or adenomas, and serious adverse events.

RESULTS

The review included 33 studies (n = 10 776 276) on the effectiveness of screening, 59 (n = 3 491 045) on the test performance of screening tests, and 131 (n = 26 987 366) on the harms of screening. In randomized clinical trials (4 trials, n = 458 002), intention to screen with 1- or 2-time flexible sigmoidoscopy vs no screening was associated with a decrease in CRC-specific mortality (incidence rate ratio, 0.74 [95% CI, 0.68-0.80]). Annual or biennial guaiac fecal occult blood test (gFOBT) vs no screening (5 trials, n = 419 966) was associated with a reduction of CRC-specific mortality after 2 to 9 rounds of screening (relative risk at 19.5 years, 0.91 [95% CI, 0.84-0.98]; relative risk at 30 years, 0.78 [95% CI, 0.65-0.93]). In observational studies, receipt of screening colonoscopy (2 studies, n = 436 927) or fecal immunochemical test (FIT) (1 study, n = 5.4 million) vs no screening was associated with lower risk of CRC incidence or mortality. Nine studies (n = 6497) evaluated the test accuracy of screening computed tomography (CT) colonography, 4 of which also reported the test accuracy of colonoscopy; pooled sensitivity to detect adenomas 6 mm or larger was similar between CT colonography with bowel prep (0.86) and colonoscopy (0.89). In pooled values, commonly evaluated FITs (14 studies, n = 45 403) (sensitivity, 0.74; specificity, 0.94) and stool DNA with FIT (4 studies, n = 12 424) (sensitivity, 0.93; specificity, 0.85) performed better than high-sensitivity gFOBT (2 studies, n = 3503) (sensitivity, 0.50-0.75; specificity, 0.96-0.98) to detect cancers. Serious harms of screening colonoscopy included perforations (3.1/10 000 procedures) and major bleeding (14.6/10 000 procedures). CT colonography may have harms resulting from low-dose ionizing radiation. It is unclear if detection of extracolonic findings on CT colonography is a net benefit or harm.

CONCLUSIONS AND RELEVANCE

There are several options to screen for colorectal cancer, each with a different level of evidence demonstrating its ability to reduce cancer mortality, its ability to detect cancer or precursor lesions, and its risk of harms.

Colonoscopy screening and surveillance guidelines

The Colonoscopy Screening and Surveillance Guidelines were developed by the Japan Gastroenterological Endoscopy Society as basic guidelines based on the scientific methods. The importance of endoscopic screening and surveillance for both detection and post-treatment follow-up of colorectal cancer has been recognized as essential to reduce disease mortality. There is limited high-level evidence in this field; therefore, we had to focus on the consensus of experts. These clinical practice guidelines consist of 20 clinical questions and eight background knowledge topics that have been determined as the current guiding principles.

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.

Triumph against cancer: invading colorectal cancer with nanotechnology

INTRODUCTION

Recent statistics have reported colorectal cancer (CRC) as the second leading cause of cancer-associated deaths in the world. Early diagnosis of CRC may help to reduce the mortality and associated complications. However, the conventional diagnostic techniques often lead to misdiagnosis, fail to differentiate benign from malignant tissue or diagnose only at an advanced stage. For the treatment of CRC, surgery, chemotherapy, immunotherapy, and radiotherapy have been employed. However, the quality of living of the CRC patients is highly compromised after employing current therapeutic approaches owing to the toxicity issues and relapse.

AREA COVERED

This review accentuates the molecular mechanisms involved in the pathogenesis, stages of CRC, conventional approaches for diagnosis and therapy of CRC and the issues confronted thereby. It provides an outlook on the advantages of employing nanotechnology-based approaches for prevention, early diagnosis, and treatment of CRC.

EXPERT OPINION

Employing nanotechnology-based approaches has demonstrated promising outcomes in the prevention, diagnosis, and treatment of CRC. Nanotechnology-based approaches can surmount the major drawbacks of traditional diagnostic and therapeutic approaches. Nanotechnology bestows the advantage of early detection of CRC which helps to undertake instant steps for offering efficient therapy and reducing the mortality rates. For the treatment of CRC, nanocarriers offer the benefit of achieving controlled drug release, improved drug bioavailability, enhanced tumor targetability and reduced adverse effects.

Microsatellite Instability in Colorectal Cancer Liquid Biopsy-Current Updates on Its Potential in Non-Invasive Detection, Prognosis and as a Predictive Marker

Colorectal cancer (CRC) is the third most commonly-diagnosed cancer in the world and ranked second for cancer-related mortality in humans. Microsatellite instability (MSI) is an indicator for Lynch syndrome (LS), an inherited cancer predisposition, and a prognostic marker which predicts the response to immunotherapy. A recent trend in immunotherapy has transformed cancer treatment to provide medical alternatives that have not existed before. It is believed that MSI-high (MSI-H) CRC patients would benefit from immunotherapy due to their increased immune infiltration and higher neo-antigenic loads. MSI testing such as immunohistochemistry (IHC) and PCR MSI assay has historically been a tissue-based procedure that involves the testing of adequate tissue with a high concentration of cancer cells, in addition to the requirement for paired normal tissues. The invasive nature and specific prerequisite of such tests might hinder its application when surgery is not an option or when the tissues are insufficient. The application of next-generation sequencing, which is highly sensitive, in combination with liquid biopsy, therefore, presents an interesting possibility worth exploring. This review aimed to discuss the current body of evidence supporting the potential of liquid biopsy as a tool for MSI testing in CRC.

Adverse events of colonoscopy in a colorectal cancer screening program with fecal immunochemical testing: a population-based observational study

Background and study aims  The aim of this study was to assess adverse events (AEs) associated with colonoscopy in the French colorectal cancer screening program with fecal occult blood test (FOBT). Patients and methods  A retrospective cohort study was performed of all colonoscopies performed from 2015 to 2018 for a positive fecal immunochemical test (FIT) in patients aged 50 to 74 years within the screening program in progress in Alsace, part of the French program. AEs were recorded through prospective voluntary reporting by community gastroenterologists and retrospective postal surveys addressed to individuals screened. They were compared with those recorded in the previous program following colonoscopies performed from 2003 to 2014 for a positive guaiac-based FOBT (gFOBT). Results  Of 9576 colonoscopies performed for a positive FIT, 6194 (64.7 %) were therapeutic. Overall, 180 AEs were recorded (18.8 ‰, 95 % CI 16.1-21.5), 114 of them (11.9 ‰, 95 % CI 9.7-14.1) requiring hospitalization, 55 (5.7‰, 95 % CI 4.2-7.3) hospitalization > 24 hours, and eight (0.8 ‰, 95 % CI 0.3-1.4) surgery. The main complications requiring hospitalization were perforation (n = 18, 1.9 ‰, 95 % CI 1.0-2.7) and bleeding (n = 31, 3.2 ‰, 95 % CI 2.1-4.4). Despite a significant increase in several risk factors for complication, the rate of AEs remained stable between gFOBT and FIT programs. Overall, we observed one death (1/27,000 colonoscopies) and three splenic injuries. Conclusions  The harms of colonoscopy in a colorectal cancer screening program with FIT are more frequent than usually estimated. This study revealed six AEs requiring hospitalization > 24 hours (three bleeds, two perforations), one necessitating surgery, and 50 minor complications per 1000 colonoscopies.

Sexual Dimorphism in Colon Cancer

A higher incidence of colorectal cancer (CRC) is found in males compared to females. Young women (18-44 years) with CRC have a better survival outcome compared to men of the same age or compared to older women (over 50 years), indicating a global incidence of sexual dimorphism in CRC rates and survival. This suggests a protective role for the sex steroid hormone estrogen in CRC development. Key proliferative pathways in CRC tumorigenesis exhibit sexual dimorphism, which confer better survival in females through estrogen regulated genes and cell signaling. Estrogen regulates the activity of a class of Kv channels (KCNQ1:KCNE3), which control fundamental ion transport functions of the colon and epithelial mesenchymal transition through bi-directional interactions with the Wnt/β-catenin signalling pathway. Estrogen also modulates CRC proliferative responses in hypoxia via the novel membrane estrogen receptor GPER and HIF1A and VEGF signaling. Here we critically review recent clinical and molecular insights into sexual dimorphism of CRC biology modulated by the tumor microenvironment, estrogen, Wnt/β-catenin signalling, ion channels, and X-linked genes.

Diagnostic accuracy of computed tomography colonography in patients at high risk for colorectal cancer: a meta-analysis

AIM

The aim was to explore the diagnostic value of computed tomographic colonography (CTC) compared with conventional colonoscopy in individuals at high risk for colorectal cancer.

METHOD

PubMed, Embase, the Cochrane Library and the Web of Science were searched by two independent reviewers for potentially eligible studies published up to 31 October 2018 that were based on a per-patient analysis. stata, meta-disc and revman were used to perform this meta-analysis. A random-effect model was used, and a subgroup analysis was conducted to explore the sources of heterogeneity.

RESULTS

A total of 14 full-text articles, involving 3578 patients, were included in this meta-analysis. The pooled sensitivity, specificity, positive likelihood ratio, negative likelihood ratio and the area under the summary receiver operating characteristic curve of CTC for detecting polyps ≥ 6 mm were 0.87 (95% CI 0.83-0.90), 0.90 (95% CI 0.86-0.93), 9.08 (95% CI 6.28-13.13), 0.14 (95% CI 0.11-0.18) and 0.94 (95% CI 0.92-0.96), respectively. For polyps ≥ 10 mm, the pooled sensitivity, specificity, positive likelihood ratio and negative likelihood ratio of CTC were 0.91 (95% CI 0.86-0.94), 0.98 (95% CI 0.95-0.99), 40.36 (95% CI 19.16-85.03), 0.90 (95% CI 0.06-0.14) and 0.98 (95% CI 0.96-0.99), respectively.

CONCLUSION

In this meta-analysis, CTC had high diagnostic accuracy for detecting polyps ≥ 6 mm and ≥ 10 mm in patients at high risk of developing colorectal cancer and it had a higher sensitivity and specificity for detecting polyps ≥ 10 mm than polyps ≥ 6 mm. However, the results should be used cautiously due to the significant heterogeneity.

Self-Reported Lower Gastrointestinal Endoscopy Use and Changes in Colorectal Cancer Mortality Rates in European Countries

To quantify the association of self-reported lower gastrointestinal endoscopy use measured in 2004/05 with colorectal cancer (CRC) mortality changes over 2004–2015 in Europe.

Triage May Improve Selection to Colonoscopy and Reduce the Number of Unnecessary Colonoscopies

Implementation of population screening for colorectal cancer by direct colonoscopy or follow-up colonoscopy after a positive fecal blood test has challenged the overall capacity of bowel examinations. Certain countries are facing serious colonoscopy capacity constraints, which have led to waiting lists and long time latency of follow-up examinations. Various options for improvement are considered, including increased cut-off values of the fecal blood tests. Results from major clinical studies of blood-based, cancer-associated biomarkers have, however, led to focus on a Triage concept for improved selection to colonoscopy. The Triage test may include subject age, concentration of hemoglobin in a feces test and a combination of certain blood-based cancer-associated biomarkers. Recent results have indicated that Triage may reduce the requirements for colonoscopy by around 30%. Such results may be advantageous for the capacity, the healthcare budgets and in particular, the subjects, who do not need an unnecessary, unpleasant and risk-associated bowel examination.

Aberrant Methylation of LINE-1 Transposable Elements: A Search for Cancer Biomarkers

Cancer remains one of the main causes of human mortality despite significant progress in its diagnostics and therapy achieved in the past decade. Massive hypomethylation of retrotransposons, in particular LINE-1, is considered a hallmark of most malignant transformations as it results in the reactivation of retroelements and subsequent genomic instability. Accumulating data on LINE-1 aberrant methylation in different tumor types indicates its significant role in cancer initiation and progression. However, direct evidence that LINE-1 activation can be used as a cancer biomarker is still limited. The objective of this review was to critically evaluate the published results regarding the diagnostic/prognostic potential of the LINE-1 methylation status in cancer. Our analysis indicates that LINE-1 hypomethylation is a promising candidate biomarker of cancer development, which, however, needs validation in both clinical and laboratory studies to confirm its applicability to different cancer types and/or stages. As LINE-1 is present in multiple cell-free copies in blood, it has advantages over single-copy genes regarding perspectives of using its methylation status as an epigenetic cancer biomarker for cell-free DNA liquid biopsy.

Cost-effectiveness analysis of colorectal cancer screening using colonoscopy, fecal immunochemical test, and risk score

BACKGROUND AND AIM

A risk-stratification score may be useful for colorectal cancer (CRC) screening, alongside screening colonoscopy (CS) and fecal immunochemical test (FIT). This study aimed to evaluate the effectiveness and cost-effectiveness of population-based CRC screening strategies using CS, FIT, and the Japanese CRC screening score.

METHODS

The effectiveness in quality-adjusted life years (QALYs), cost-effectiveness, and required number of CS procedures were evaluated for screening strategies with primary screening CS (strategy 1), FIT (strategy 2), and the risk score (strategy 3), using a simulation model analysis with two scenarios. In scenario 1, uptake rates for all tests were 60%. In scenario 2, uptake rates for FIT and a risk score were 40%, and those for screening CS and CS following a positive FIT or high risk score were 20% and 70%, respectively.

RESULTS

In scenario 1, strategy 1 gained the highest QALYs and required the highest cost. The incremental cost-effectiveness ratios per QALY gained for strategy 1 against the others were lower than 5 000 000 JPY. Strategy 1 required more than twice as many CS procedures as the other strategies. In scenario 2, strategy 3 had the highest QALYs and lowest cost, and strategy 1 had the lowest QALYs and highest cost.

CONCLUSIONS

Screening CS has the potential to be the most effective and cost-effective form of CRC screening, although it requires a large number of CS procedures. However, if non-invasive tests are preferred by recipients, other screening strategies, particularly those using the risk score, can be more effective and cost-effective.

The experience with colorectal cancer screening in the Czech Republic: the detection at earlier stages and improved clinical outcomes

OBJECTIVES

Colorectal cancer (CRC) remains a major health burden. Although screening is recommended and considered beneficial, further data on its positive effects are needed for worldwide implementation.

STUDY DESIGN

The aim of our national multicentre prospective observational study was to reveal and document clinicopathological differences in CRC diagnosed by screening and presented by disease symptoms as well as assess the efficiency of the screening programme in the Czech Republic.

METHODS

Between March 2013 and September 2015, a total of 265 patients were enrolled in 12 gastroenterology centres across the Czech Republic. Patients were divided into screening and symptomatic groups and compared for pathology status and clinical characteristics. Screening was defined as a primary screening colonoscopy or a colonoscopy after a positive faecal occult blood test in an average-risk population.

RESULTS

The distribution of CRC stages was significantly (statistically and clinically) favourable in the screening group (predominance of stages 0, I and II) compared with the non-screening group (P < 0.001). The presence of distant and local metastases was significantly less frequent in the screening group than in the symptomatic group (P < 0.001). Patients in the screening group had a higher probability of radical surgery (R0) than those diagnosed based on symptoms (P < 0.001). Systemic palliative treatment was indicated in two patients in the screening group compared with 23 patients in the non-screening group (P = 0.018).

CONCLUSION

CRC diagnosed by screening disclosed less advanced clinicopathological characteristics and results in patients with a higher probability of radical surgery (R0) than diagnoses established based on symptoms, with subsequent management differing accordingly between both groups. These results advocate the implementation of a suitable worldwide screening programme.

L1CAM, CA9, KLK6, HPN, and ALDH1A1 as Potential Serum Markers in Primary and Metastatic Colorectal Cancer Screening

BACKGROUND

Colorectal cancer (CRC) screening at the earlier stages could effectively decrease CRC-related mortality and incidence; however, accurate screening strategies are still lacking. Considerable interest has been generated in the detection of less invasive tests requiring a small sample volume with the potential to detect several cancer biomarkers simultaneously. Due to this, the ELISA-based method was undertaken in this study.

METHODS

Concentrations of neural cell adhesion molecule L1 (L1CAM), carbonic anhydrase IX (CA9), mesothelin (MSLN), midkine (MDK), hepsin (HPN), kallikrein 6 (KLK6), transglutaminase 2 (TGM2) aldehyde dehydrogenase 1 family, member A1 (ALDH1A1), epithelial cell adhesion molecule (EpCAM), and cluster of differentiation 44 (CD44) from blood serum of 36 primary CRC and 24 metastatic CRC (mCRC) were calculated via MAGPIX® System (Luminex Corporation, USA).

RESULTS

Significantly increased concentration (p < 0.05) of three serum biomarkers (L1CAM, CA9, and HPN) were shown in mCRC when compared with primary CRC. HPN and KLK6 showed significant differences (p < 0.05) in concentration among different stages of CRC. In contrast, levels of HPN and ALDH1A1 were significantly elevated (p < 0.05) in chemotherapy-treated CRC patients as compared with nontreated ones. Conclusion: Serum biomarkers could act as a potential early CRC diagnostics test, but further additional testings are needed.

Findings on Colonoscopy after Diverticulitis: A Multicenter Review

Diverticular disease is a common problem where patients with diverticulosis have a 1–4 per cent risk of acute diverticulitis. Current guidelines recommend a colonoscopy after.the resolution of acute diverticulitis. The aim of this study was to evaluate the yield of significant findings on colonoscopy after an episode of diverticulitis. This is a retrospective analysis of patients who underwent colonoscopy after an episode of diverticulitis between November 2005 and August 2017 at three major teaching hospitals. Advanced adenomas were defined as adenomas ≥1 cm, serrated adenomas, and tubulovillous or villous adenomas. A total of 584 patients (298 males; 51%) underwent colonoscopy for a history of diverticulitis after resolution of acute symptoms. Colonoscopy was complete in 488 patients (84%). Among these 488 patients, 446 had diverticular disease, 31 had advanced adenomas, and four had adenocarcinomas. Colonoscopies were incomplete in 96 patients (16%). Forty-six of those patients underwent surgery. The overall incidence of advanced adenomas and adenocarcinomas was 32 (5.4%) and nine (1.5%), respectively. In our study, the prevalence of advanced adenomas and adenocarcinomas was relatively high compared with the average risk individuals. Our findings support that patients after an episode of diverticulitis should continue to get a colonoscopy.

Opportunistic use of radiological measures of visceral adiposity for assessment of risk of colorectal adenoma

BACKGROUND

Recent evidence suggested that radiological measures of visceral adiposity are a better tool for risk assessment of colorectal adenomas. The aim of this study was to investigate the association of visceral adiposity with the development of colorectal adenomas.

METHODS

A retrospective review of all cases of computed tomography-confirmed acute diverticulitis from November 2015 to April 2018 was performed. Data collated included basic demographics, computed tomography scan results (uncomplicated versus complicated diverticulitis), treatment modality (conservative versus intervention), outcomes and follow-up colonoscopy results within 12 months of presentation. The patients were divided into no adenoma (A) and adenoma (B) groups. Visceral fat area (VFA), subcutaneous fat area (SFA) and VFA/SFA ratio (V/S) were measured at L4/L5 level. Statistical analysis was performed to evaluation the association of VFA, SFA, V/S and different thresholds with the risk of adenoma formation.

RESULTS

A total of 169 patients were included in this study (A:B = 123:46). The mean ± standard deviation for VFA was higher in group B (201 ± 87 cm² versus 176 ± 79 cm² ) with a trend towards statistical significance (P = 0.08). There was no difference in SFA and V/S in both groups. When the VFA >200 cm² was analysed, it was associated with a threefold risk of adenoma formation (odds ratio 2.7, 95% confidence interval 1.35-5.50, P = 0.006). Subgroup analysis of gender with VFA, SFA and V/S found that males have a significantly higher VFA in group B (220.0 ± 95.2 cm² versus 187.3 ± 69.2 cm² ; P = 0.05).

CONCLUSIONS

The radiological measurement of visceral adiposity is a useful tool for opportunistic assessment of risk of colorectal adenoma.

Mortality and Rate of Hospitalization in a Colonoscopy Screening Program From a Randomized Health Services Study

BACKGROUND & AIMS

It is difficult to quantify adverse events related to screening colonoscopy due to lack of valid and adequately powered comparison groups. We compared mortality and rate of unplanned hospitalizations among subjects who underwent screening colonoscopies within the Polish Colonoscopy Screening Program (PCSP) vs unscreened matched controls in Poland.

METHODS

Persons 55-64 years old living in the area covered by the PCSP from 2012 through 2015 were assigned in a (1:1) to a group invited for screening colonoscopy (n = 338,477) or a matched group that would be invited 5 years later (controls, n = 338,557). All subjects in the screening group were assigned proposed screening colonoscopy dates (actual dates when invitees confirmed or rescheduled colonoscopy) and those in the control group were assigned virtual dates corresponding to the matched individuals from the screening group. In the screening group, 55,390 subjects (16.4%) underwent screening colonoscopy. Mortality and hospitalization data were obtained from National Registries. We compared mortality and rate of hospitalization between the groups for defined intervals before and after colonoscopy date. Hospitalizations were divided into related and unrelated to colonoscopy based on ICD codes by 3 specialists. Our primary aim was to compare mortality and hospitalization 6 weeks before and 30 days following the actual or virtual date of colonoscopy in the screening or control group.

RESULTS

In the intent to treat analysis, overall there were no significant differences in mortality between the colonoscopy group and control group (0.22% vs 0.22%; risk difference less than .01%; 95% CI, decrease of 0.02% to 0.02%; P = .913). The overall rate of unplanned hospitalization was significantly higher for the colonoscopy group (2.39% vs 2.31% for the control group; risk difference, 0.08%; 95% CI, 0.01%-0.15%; P=.026) for the entire observation period. This was due to the higher rate of hospitalizations after screening (1.10% vs 1.01% for the control group; risk difference, 0.09%; 95% CI, 0.04%-0.14%; P < .001) including higher proportion of hospitalizations that were assessed as related to colonoscopy (0.24% vs 0.22% for the control group; risk difference, 0.02%; 95% CI, 0.00%-0.05%; P = .046). In the per-protocol analysis, the overall rate of hospitalizations did not differ significantly between control and screening colonoscopy groups (1.87% vs 1.90%; P=.709). However, screening colonoscopy did increase rates of related hospitalizations after the date of screening (from 0.14% to 0.31%; P < .001).

CONCLUSIONS

In an analysis of data from the PCSP, we found high-quality evidence that colonoscopy as a screening intervention does not increase mortality before or after colonoscopy. However, it may be associated with a small but significant increase in unplanned hospitalizations, especially after the colonoscopy is completed.

Cost-effectiveness Evaluation of Targeted Surgical and Endoscopic Therapies for Early Colorectal Adenocarcinoma Based on Biomarker Profiles

IMPORTANCE

Colorectal cancer (CRC) is the second leading cause of cancer-related mortality in the United States. The prognosis for patients with CRC varies widely, but new prognostic biomarkers provide the opportunity to implement a more individualized approach to treatment selection.

OBJECTIVE

To assess the cost-effectiveness of 3 therapeutic strategies, namely, endoscopic therapy (ET), laparoscopic colectomy (LC), and open colectomy (OC), for patients with T1 CRC with biomarker profiles that prognosticate varying levels of tumor progression in the US payer perspective.

DESIGN, SETTING, AND PARTICIPANTS

In this economic evaluation study, a Markov model was developed for the cost-effectiveness analysis. Risks of all-cause mortality and recurrent cancer after ET, LC, or OC were estimated with a 35-year time horizon. Quality of life was based on EuroQoL 5 Dimensions scores reported in the published literature. Hospital and treatment costs reflected Medicare reimbursement rates. Deterministic and probabilistic sensitivity analyses were performed. Data from patients with T1 CRC and 6 biomarker profiles that included adenomatous polyposis coli (APC), TP53 and/or KRAS, or BRAFV600E were used as inputs for the model. Data analyses were conducted from February 27, 2019, to May 13, 2019.

EXPOSURES

Endoscopic therapy, LC, and OC.

MAIN OUTCOMES AND MEASURES

The primary outcomes were unadjusted life-years, quality-adjusted life-years (QALYs), and the incremental cost-effectiveness ratio (ICER) between competing treatment strategies.

RESULTS

Endoscopic therapy had the highest QALYs and the lowest cost and was the dominant treatment strategy for T1 CRC with the following biomarker profiles: BRAFV600E, APC(1)/KRAS/TP53, APC(2) or APC(2)/KRAS or APC(2)/TP53, or APC(1) or APC(1)/KRAS or APC(1)/TP53. The QALYs gained ranged from 16.97 to 17.22, with costs between $68 902.75 and $77 784.53 in these subgroups. For the 2 more aggressive biomarker profiles with worse prognoses (APC(2)/KRAS/TP53 and APCwt [wild type]), LC was the most effective strategy (with 16.45 and 16.61 QALYs gained, respectively) but was not cost-effective. Laparoscopic colectomy cost $65 234.87 for APC(2)/KRAS/TP53 and $71 250.56 for APCwt, resulting in ICERs of $113 290 per QALY and $178 765 per QALY, respectively.

CONCLUSIONS AND RELEVANCE

This modeling analysis found that ET was the most effective strategy for patients with T1 CRC with less aggressive biomarker profiles. For patients with more aggressive profiles, LC was more effective but was costly, rendering ET the cost-effective option. This study highlights the potential utility of prognostic biomarkers in T1 CRC treatment selection.