Colorectal Cancer Risk Following Adenoma Removal: A Large Prospective Population-Based Cohort Study

Colon Polyp Surveillance: Separating the Wheat From the Chaff

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

Surveillance Colonoscopy Findings in Older Adults With a History of Colorectal Adenomas

Importance

Postpolypectomy surveillance is a common colonoscopy indication in older adults; however, guidelines provide little direction on when to stop surveillance in this population.

Objective

To estimate surveillance colonoscopy yields in older adults.

Design, Setting, and Participants

This population-based cross-sectional study included individuals 70 to 85 years of age who received surveillance colonoscopy at a large, community-based US health care system between January 1, 2017, and December 31, 2019; had an adenoma detected 12 or more months previously; and had at least 1 year of health plan enrollment before surveillance. Individuals were excluded due to prior colorectal cancer (CRC), hereditary CRC syndrome, inflammatory bowel disease, or prior colectomy or if the surveillance colonoscopy had an inadequate bowel preparation or was incomplete. Data were analyzed from September 1, 2022, to February 22, 2024.

Exposures

Age (70-74, 75-79, or 80-85 years) at surveillance colonoscopy and prior adenoma finding (ie, advanced adenoma vs nonadvanced adenoma).

Main Outcomes and Measures

The main outcomes were yields of CRC, advanced adenoma, and advanced neoplasia overall (all ages) by age group and by both age group and prior adenoma finding. Multivariable logistic regression was used to identify factors associated with advanced neoplasia detection at surveillance.

Results

Of 9740 surveillance colonoscopies among 9601 patients, 5895 (60.5%) were in men, and 5738 (58.9%), 3225 (33.1%), and 777 (8.0%) were performed in those aged 70-74, 75-79, and 80-85 years, respectively. Overall, CRC yields were found in 28 procedures (0.3%), advanced adenoma in 1141 (11.7%), and advanced neoplasia in 1169 (12.0%); yields did not differ significantly across age groups. Overall, CRC yields were higher for colonoscopies among patients with a prior advanced adenoma vs nonadvanced adenoma (12 of 2305 [0.5%] vs 16 of 7435 [0.2%]; P = .02), and the same was observed for advanced neoplasia (380 of 2305 [16.5%] vs 789 of 7435 [10.6%]; P < .001). Factors associated with advanced neoplasia at surveillance were prior advanced adenoma (adjusted odds ratio [AOR], 1.65; 95% CI, 1.44-1.88), body mass index of 30 or greater vs less than 25 (AOR, 1.21; 95% CI, 1.03-1.44), and having ever smoked tobacco (AOR, 1.14; 95% CI, 1.01-1.30). Asian or Pacific Islander race was inversely associated with advanced neoplasia (AOR, 0.81; 95% CI, 0.67-0.99).

Conclusions and Relevance

In this cross-sectional study of surveillance colonoscopy yield in older adults, CRC detection was rare regardless of prior adenoma finding, whereas the advanced neoplasia yield was 12.0% overall. Yields were higher among those with a prior advanced adenoma than among those with prior nonadvanced adenoma and did not increase significantly with age. These findings can help inform whether to continue surveillance colonoscopy in older adults.

Polyps are detected more often in early colonoscopies

OBJECTIVE

To examine the time variation in polyp detection for colonoscopies performed in a tertiary hospital and to explore independent factors that predict polyp detection rate (PDR).

METHODS

Data on all patients who underwent colonoscopy for the diagnostic purpose at our endoscopy center in Zhongnan Hospital of Wuhan University from January 2021 to December 2021 were reviewed. The start time of included colonoscopies for eligible patients was recorded. PDR and polyps detected per colonoscopy (PPC) were calculated. The endoscopists' schedules were classified into full-day and half-day shifts according to their participation in the morning and afternoon colonoscopies.

RESULTS

Data on a total of 12116 colonoscopies were analyzed, with a PDR of 38.03% for all the patients and 46.38% for patients ≥50 years. PDR and PPC significantly decreased as the day progressed (both p < .001). For patients ≥50 years, PDR declined below 40% at 13:00-13:59 and 16:00-16:59. The PDR in the morning was higher than that in the afternoon for both half-day (p = .019) and full-day procedures (p < .001). In multivariate analysis, start time, patient gender, age, conscious sedation, and bowel preparation quality significantly predicted PDR (p < .001).

CONCLUSIONS

The polyp detection declined as the day progressed. A continuous work schedule resulted in a subpar PDR. Colonoscopies performed in the morning had a higher PDR than that in the afternoon. Patient gender, age, conscious sedation, and bowel preparation quality were identified as the independent predictors of PDR.

Risk Factors for Metachronous Colorectal Cancer or Advanced Adenomas After Endoscopic Resection of High-risk Adenomas

BACKGROUND & AIMS

Among the characteristics of high-risk adenomas (HRAs), some may predict a higher risk of metachronous advanced lesions. Our aim was to assess which HRA characteristics are associated with high risk of metachronous colorectal cancer (CRC) or advanced adenomas (AAs).

METHODS

We systematically searched Pubmed, EMBASE, and Cochrane for cohort studies and clinical trials of CRC or AA incidence at surveillance stratified by baseline lesion size, histology, and multiplicity. We calculated pooled relative risks (RRs) using a random-effects model. Heterogeneity was assessed with the I² statistic.

RESULTS

Fifty-five studies were included, with 936,540 patients with mean follow-up 5.4 ± 2.9 years. CRC incidence per 1000 person-years was 2.6 (2.1-3.0) for adenomas ≥20 mm, 2.7 (2.2-3.2) for high-grade dysplasia (HGD), 2.0 (1.8-2.3) for villous component, 0.8 (0.1-1.4) for ≥5 adenomas, 1.0 (0.7-1.2) for ≥3 adenomas. Metachronous CRC risk was higher in adenomas ≥20 mm vs 10 to 19 mm (RR, 2.08; 95% confidence interval [CI], 1.20-3.61), HGD vs low-grade dysplasia (RR, 2.89; 95% CI, 1.88-4.44), villous vs tubular (RR, 1.75; 95% CI, 1.33-2.31). No significant differences in CRC risk were found in ≥3 adenomas vs 1 to 2 (RR, 1.24; 95% CI, 0.84-1.83), nor in ≥5 adenomas vs 3 to 4 (RR, 0.79; 95% CI, 0.30-2.11). Compared with normal colonoscopy, RR for CRC risk was 2.61 (95% CI, 2.06-3.32) for ≥10mm, 6.62 (95% CI, 4.60-9.52) for HGD, 3.58 (95% CI, 2.24-5.73) for villous component, and 2.03 (95% CI, 1.40-2.94) for ≥3 adenomas. Similar trends were seen for metachronous AAs.

CONCLUSION

Metachronous CRC risk is highest in patients with baseline adenomas with ≥20 mm or HGD. Multiplicity does not seem to be associated with substantially higher CRC risk in the near term.

Yield of Surveillance Colonoscopy in Older Adults with a History of Polyps: A Systematic Review and Meta-Analysis

BACKGROUND

The benefit of surveillance colonoscopy in older adults is not well described.

AIMS

To quantify the detection of colorectal cancer (CRC) and advanced polyps during surveillance colonoscopy in older adults with a history of colon polyps.

METHODS

We conducted a systematic review (MEDLINE, Cochrane Library, Web of Science, and Embase) for all published studies through May 2020 in adults age > 70 undergoing surveillance colonoscopy. The main outcome was CRC and advanced polyps detection. We performed meta-analysis to pool results by age (>70 vs. 50-70).

RESULTS

The search identified 6239 studies, of which 569 underwent full-text review and 64 data abstraction, of which 19 were included. The risk of detecting CRC (N = 11) was higher in those >70 compared to 50-70 (risk ratio 1.5 (95% CI 1.1-2.2); risk difference 0.8% (95% CI -0.2%-1.8%)). Similarly, the risk of detecting advanced polyps (N = 8) was higher in those >70 compared to 50-70 (risk ratio 1.3 (95% CI 1.2-1.3), risk difference 2.7% (95% CI 1.3%-4.0%)). Most studies did not stratify results by baseline polyp risk.

CONCLUSIONS

The detection of CRC and advanced polyps during surveillance colonoscopy in older individuals was higher than in younger controls; however, the absolute risk increase for both was small. These differences must be weighed against competing medical problems and limited life expectancy in older adults when making decisions about surveillance colonoscopy. More primary data on the risks of CRC and advanced polyps accounting for number of past colonoscopies, prior polyp risk, and duration of time since last polyp are needed.

Surveillance Recommendation for Colonoscopy after Polypectomy

The incidence and mortality of colorectal cancer (CRC) have declined over the past several decades, largely due to improvement and uptake in screening, particularly with colonoscopy. The US Multi-Society Task Force on CRC published guidelines for surveillance after polypectomy in 2012, which were updated in 2020 with some important changes, and this review will provide an updated overview of evidence and outcomes of surveillance after polypectomy. Notable modifications to surveillance guidelines include increasing interval time between colonoscopies from 5 to 7 to 10 years for 1 to 2 low-risk adenomas (<10 mm) and from 3 years to 3 to 5 years when 3 to 4 low-risk adenomas are identified.

Long-term risk of colorectal cancer after removal of adenomas during screening colonoscopies in a large community-based population in China

Patients with conventional adenoma removal are recommended to undergo colonoscopy surveillance to prevent colorectal cancer (CRC). However, evidence supporting the guidelines of colonoscopy surveillance is limited, especially among the Chinese population. We investigated the association between colonoscopy adenoma findings and CRC risk among individuals aged 40 to 74 years who underwent baseline colonoscopy from 2007 to 2016 in Jiashan and Haining, Zhejiang, China; 34 382 participants were categorized into advanced adenoma, nonadvanced adenoma and no adenoma based on adenoma findings. A multivariable Cox regression model was used to estimate the hazard ratio (HR) of CRC incidence with adjustment for potential confounding factors. After a median follow-up time of 7.7 years, 113 incident cases of CRC were identified (18 occurred in 1632 participants with advanced adenoma, 16 in 3973 participants with nonadvanced adenoma and 79 in 28 777 participants with no adenoma). Compared to no adenoma group, the adjusted HR for CRC in advanced adenoma group was 4.01 (95% CI, 2.37-6.77). For nonadvanced adenomas, individuals with ≥3 adenomas showed an increased risk of CRC (HR, 3.65; 95% CI, 1.43-9.31), but no significantly increased risk of CRC was found for 1 to 2 nonadvanced adenomas, compared to those with no adenoma. Our study suggested that the risk of subsequent CRC increased in individuals with high-risk adenoma (at least one advanced adenoma or ≥3 nonadvanced adenomas), but not in those with 1 to 2 nonadvanced adenomas. These results provide the first evidence from the Chinese population for the current surveillance guidelines.

Screening and prevention of colorectal cancer

Mortality from colorectal cancer is reduced through screening and early detection; moreover, removal of neoplastic lesions can reduce cancer incidence. While understanding of the risk factors, pathogenesis, and precursor lesions of colorectal cancer has advanced, the cause of the recent increase in cancer among young adults is largely unknown. Multiple invasive, semi- and non-invasive screening modalities have emerged over the past decade. The current emphasis on quality of colonoscopy has improved the effectiveness of screening and prevention, and the role of new technologies in detection of neoplasia, such as artificial intelligence, is rapidly emerging. The overall screening rates in the US, however, are suboptimal, and few interventions have been shown to increase screening uptake. This review provides an overview of colorectal cancer, the current status of screening efforts, and the tools available to reduce mortality from colorectal cancer.

A Meta-Analysis of Obesity and Risk of Colorectal Cancer in Patients with Lynch Syndrome: The Impact of Sex and Genetics

There appears to be a sex-specific association between obesity and colorectal neoplasia in patients with Lynch Syndrome (LS). We meta-analyzed studies reporting on obesity and colorectal cancer (CRC) risk in LS patients to test whether obese subjects were at increased risk of cancer compared to those of normal weight. We explored also a possible sex-specific relationship between adiposity and CRC risk among patients with LS. The summary relative risk (SRR) and 95% confidence intervals (CI) were calculated through random effect models. We investigated the causes of between-study heterogeneity and assessed the presence of publication bias. We were able to retrieve suitable data from four independent studies. We found a twofold risk of CRC in obese men compared to nonobese men (SRR = 2.09; 95%CI: 1.23–3.55, I² = 33%), and no indication of publication bias (p = 0.13). No significantly increased risk due to obesity was found for women. A 49% increased CRC risk for obesity was found for subjects with an MLH1 mutation (SRR = 1.49; 95%CI: 1.11–1.99, I² = 0%). These results confirm the different effects of sex on obesity and CRC risk and also support the public measures to reduce overweight in people with LS, particularly for men.

Circulating plasma microRNAs in colorectal neoplasia: A pilot study in assessing response to therapy

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This pilot study examines a microRNA panel as a biomarker for response to surgical resection in colorectal cancer or colorectal advanced adenoma.

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A panel of 11 microRNAs was developed through screening and previous studies.

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Six miRNA are significantly increased following colorectal cancer resection.

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Three miRNA are significantly increased following colorectal advanced adenoma resection.

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The results of this study suggest that serum microRNA expression could be followed as a marker for response to therapy.

Introduction

Current serological surveillance markers to monitor colorectal cancer (CRC) or colorectal advanced adenomas (CAA) are hampered by poor sensitivity and specificity. The aim of this study is to identify and validate a panel of plasma microRNAs which change in expression after resection of such lesions.

Methods

A prospectively maintained colorectal surgery database was queried for patients in whom both pre- and post-procedural serum samples had been obtained. An initial screening analysis of CRC and CAA patients (5 each) was conducted using screening cards for 380 miRNAs. Four identified miRNAs were combined with a previously described panel of 7 miRNAs that were diagnostically predictive of CRC and CAA. Differential miRNA expression was assessed using quantitative real-time polymerase chain reaction(qRT-PCR).

Results

Fifty patients were included (n = 27 CRC, n = 23 CAA). There was no difference in age, gender, or race profile of CRC patients compared to CAA patients. Six miRNA were significantly increased after CRC resection (miR-324, let7b, miR-454, miR-374a, miR-122, miR-19b, all p<0.05), while three miRNAs were significantly increased following CAA resection (miR-454, miR-374a, miR-122, all p<0.05). Three miRNA were increased in common for both (miR-454, miR-374a, miR-122).

Discussion

The expression of miRNAs associated with neoplasia (either CRC or CAA) was significantly increased following surgical resection or endoscopic removal of CRC or CAA. Future studies should focus on the evaluation of these miRNAs in CRC and CAA prognosis.

Patient Preferences in Surveillance: Findings From a Discrete Choice Experiment in the "My Follow-Up" Study

OBJECTIVES

Approximately 800 000 people die globally from colorectal cancer (CRC) every year. Prevention programs promote early detection, but for people with precancerous lesions, tailoring surveillance to include lifestyle-change programs could enhance prevention potential and improve outcomes.

METHODS

Those with intermediate or high-risk polyps removed during CRC screening colonoscopy within the Northern Ireland CRC Screening Programme were invited to complete 8 discrete choice questions about tailored surveillance, analyzed using random-parameters logit and a latent class modeling approach.

RESULTS

A total of 231 participants (77% male) self-reported comorbid hypertension (53%), high cholesterol (48%), and mean body mass index of 28.7 (overweight). Although 39% of participants were unaware of their CRC risk status, 30.9% indicated they were already making changes to reduce their risk. Although all respondents were significantly risk- and cost-averse, the latent class analysis identified 3 segments (classes): 1. Class 1 (26.8%) significantly favored phone or email support for a lifestyle change, a 17-month testing interval, and noninvasive testing. 2. Class 2 (48.4%) preferred the status quo. 3. Class 3 (24.7%) significantly favored further risk reduction and invasive testing.

CONCLUSIONS

This is the first documented preference study focusing on postpolypectomy surveillance offering lifestyle interventions. Although current care is strongly preferred, risk and cost aversion are important for participants. Latent class analysis shows that some respondents are willing to change diet and lifestyle behaviors, reflecting a teachable moment, with opportunities to personalize and optimize surveillance. Significant discordance between perceived and known risk of recurrence and limited recall of risk information provided within current practice suggest necessary improvements to surveillance programs.

The Case for High-Quality Colonoscopy Remaining a Premier Colorectal Cancer Screening Strategy in the United States

Most colorectal cancer screening in the United States occurs in the opportunistic setting, where screening is initiated by a patient-provider interaction. Colonoscopy provides the longest-interval protection, and high-quality colonoscopy is ideally suited to the opportunistic setting. Both detection and colonoscopic resection have improved as a result of intense scientific investigation. Further improvements in detection are expected with the introduction of artificial intelligence programs into colonoscopy platforms. We may expect recommended intervals or colonoscopy after negative examinations performed by high-quality detectors to expand beyond 10 years. Thus, high-quality colonoscopy remains an excellent approach to colorectal cancer screening in the opportunistic setting.

Type 2 diabetes impacts colorectal adenoma detection in screening colonoscopy

Background: Diabetes is associated with an increased risk of colorectal cancer (CRC). We conducted a retrospective analysis of adenoma detection rates (ADR) in initial screening colonoscopies to further investigate the role of diabetes in adenoma detection. Methods: A chart review was performed on initial average risk screening colonoscopies (ages 45–75) during 2012–2015. Data collected included basic demographics, insurance, BMI, family history of CRC, smoking, diabetes, and aspirin use. Multivariable generalized linear mixed models for binary outcomes were used to examine the relationship between diabetes and variables associated with CRC risk and ADR. Results: Of 2865 screening colonoscopies, 282 were performed on patients with type 2 diabetes (T2DM). Multivariable analysis suggested that T2DM (OR = 1.49, 95% CI:1.13–1.97, p = 0.0047) was associated with an increased ADR, as well as smoking, older age, higher BMI and male sex (all p < 0.05). For patients with T2DM, those not taking diabetes medications were more likely to have an adenoma than those taking medication (OR = 2.38, 95% CI:1.09–5.2, p = 0.03). Conclusion: T2DM has an effect on ADR after controlling for multiple confounding variables. Early interventions for prevention of T2DM and prescribing anti-diabetes medications may reduce development of colonic adenomas and may contribute to CRC prevention.

Long-term Risk of Colorectal Cancer and Related Death After Adenoma Removal in a Large, Community-based Population

BACKGROUND & AIMS

The long-term risks of colorectal cancer (CRC) and CRC-related death following adenoma removal are uncertain. Data are needed to inform evidence-based surveillance guidelines, which vary in follow-up recommendations for some polyp types. Using data from a large, community-based integrated health care setting, we examined the risks of CRC and related death by baseline colonoscopy adenoma findings.

METHODS

Participants at 21 medical centers underwent baseline colonoscopies from 2004 through 2010; findings were categorized as no-adenoma, low-risk adenoma, or high-risk adenoma. Participants were followed until the earliest of CRC diagnosis, death, health plan disenrollment, or December 31, 2017. Risks of CRC and related deaths among the high- and low-risk adenoma groups were compared with the no-adenoma group using Cox regression adjusting for confounders.

RESULTS

Among 186,046 patients, 64,422 met eligibility criteria (54.3% female; mean age, 61.6 ± 7.1 years; median follow-up time, 8.1 years from the baseline colonoscopy). Compared with the no-adenoma group (45,881 patients), the high-risk adenoma group (7563 patients) had a higher risk of CRC (hazard ratio [HR] 2.61; 95% confidence interval [CI] 1.87-3.63) and related death (HR 3.94; 95% CI 1.90-6.56), whereas the low-risk adenoma group (10,978 patients) did not have a significant increase in risk of CRC (HR 1.29; 95% CI 0.89-1.88) or related death (HR 0.65; 95% CI 0.19-2.18).

CONCLUSIONS

With up to 14 years of follow-up, high-risk adenomas were associated with an increased risk of CRC and related death, supporting early colonoscopy surveillance. Low-risk adenomas were not associated with a significantly increased risk of CRC or related deaths. These results can inform current surveillance guidelines for high- and low-risk adenomas.

British Society of Gastroenterology/Association of Coloproctology of Great Britain and Ireland/Public Health England post-polypectomy and post-colorectal cancer resection surveillance guidelines

These consensus guidelines were jointly commissioned by the British Society of Gastroenterology (BSG), the Association of Coloproctology of Great Britain and Ireland (ACPGBI) and Public Health England (PHE). They provide an evidence-based framework for the use of surveillance colonoscopy and non-colonoscopic colorectal imaging in people aged 18 years and over. They are the first guidelines that take into account the introduction of national bowel cancer screening. For the first time, they also incorporate surveillance of patients following resection of either adenomatous or serrated polyps and also post-colorectal cancer resection. They are primarily aimed at healthcare professionals, and aim to address:Which patients should commence surveillance post-polypectomy and post-cancer resection?What is the appropriate surveillance interval?When can surveillance be stopped? two or more premalignant polyps including at least one advanced colorectal polyp (defined as a serrated polyp of at least 10 mm in size or containing any grade of dysplasia, or an adenoma of at least 10 mm in size or containing high-grade dysplasia); or five or more premalignant polyps The Appraisal of Guidelines for Research and Evaluation (AGREE II) instrument provided a methodological framework for the guidelines. The BSG's guideline development process was used, which is National Institute for Health and Care Excellence (NICE) compliant.two or more premalignant polyps including at least one advanced colorectal polyp (defined as a serrated polyp of at least 10 mm in size or containing any grade of dysplasia, or an adenoma of at least 10 mm in size or containing high-grade dysplasia); or five or more premalignant polyps The key recommendations are that the high-risk criteria for future colorectal cancer (CRC) following polypectomy comprise either:two or more premalignant polyps including at least one advanced colorectal polyp (defined as a serrated polyp of at least 10 mm in size or containing any grade of dysplasia, or an adenoma of at least 10 mm in size or containing high-grade dysplasia); or five or more premalignant polyps This cohort should undergo a one-off surveillance colonoscopy at 3 years. Post-CRC resection patients should undergo a 1 year clearance colonoscopy, then a surveillance colonoscopy after 3 more years.

Chemoprevention of Colorectal Cancer

Although colorectal cancer (CRC) screening has reduced the incidence of and mortality from CRC, chemoprevention strategies have the potential to further reduce CRC incidence and mortality. Chemoprevention agents might be used for average-risk as well as high-risk groups, and to prevent CRC recurrence after therapy. CRC chemoprevention agents that have been studied include aspirin, nonaspirin nonsteroidal anti-inflammatory drugs, statins, agents that target metabolic pathways, and vitamins and minerals. We review the prospect of chemoprevention of CRC, results from preclinical and human studies, challenges, and future directions.

High-Intensity Versus Low-Intensity Surveillance for Patients With Colorectal Adenomas: A Cost-Effectiveness Analysis

BACKGROUND

Surveillance of patients with colorectal adenomas has limited long-term evidence to support current practice.

OBJECTIVE

To compare the lifetime benefits and costs of high- versus low-intensity surveillance.

DESIGN

Microsimulation model.

DATA SOURCES

U.S. cancer registry, cost data, and published literature.

TARGET POPULATION

U.S. patients aged 50, 60, or 70 years with low-risk adenomas (LRAs) (1 to 2 small adenomas) or high-risk adenomas (HRAs) (3 to 10 small adenomas or ≥1 large adenoma) removed after screening with colonoscopy or fecal immunochemical testing (FIT).

TIME HORIZON

Lifetime.

PERSPECTIVE

Societal.

INTERVENTION

No further screening or surveillance, routine screening after 10 years, low-intensity surveillance (10 years after LRA removal and 5 years after HRA removal), and high-intensity surveillance (5 years after LRA removal and 3 years after HRA removal).

OUTCOME MEASURES

Colorectal cancer (CRC) incidence and incremental cost-effectiveness.

RESULTS OF BASE-CASE ANALYSIS

Without surveillance or screening, lifetime CRC incidence for patients aged 50 years was 10.9% after LRA removal and 17.2% after HRA removal at screening colonoscopy. Subsequent colonoscopic screening, low-intensity surveillance, or high-intensity surveillance decreased incidence by 39%, 46% to 48%, and 55% to 56%, respectively. Incidence of CRC and surveillance benefits were higher for adenomas detected at FIT screening and lower for older patients. High-intensity surveillance cost less than $30 000 per quality-adjusted life-year (QALY) gained compared with low-intensity surveillance.

RESULTS OF SENSITIVITY ANALYSIS

High-intensity surveillance cost less than $100 000 per QALY gained in most alternative scenarios for adenoma recurrence, CRC incidence, longevity, quality of life, screening ages, surveillance ages, test performance, disutilities, and cost.

LIMITATION

Few surveillance outcome data exist.

CONCLUSION

The model suggests that high-intensity surveillance as recommended in the United States provides modest but clinically relevant benefits over low-intensity surveillance at acceptable cost.

PRIMARY FUNDING SOURCE

National Cancer Institute.

Assessing adherence and cost-benefit of colorectal cancer screening for accountable providers

The objective of this study was to assess adherence and costs-benefits of colorectal cancer (CRC) screenings from an accountable care organization/population health perspective. We performed a retrospective review of 94 patients (50-75 years of age) in an integrated safety net system for whom fecal CRC screening was abnormal for the period of June 1, 2014, to June 1, 2016. A cost-benefit model was constructed using Medicare payment rates and a sensitivity analysis. Most patients included in the study (64/94, 68%) received or were offered a colonoscopy. Of those receiving a colonoscopy, 24 of 45 (53%) had an abnormal finding. Total direct medical costs avoided by screening the patient panel was $32,926 but could have exceeded $63,237 had more patients received follow-up colonoscopies. A sensitivity analysis with 1000 patients demonstrated total monetary benefits between $2.2 million and $8.16 million when follow-up and colonoscopy rates were allowed to vary. Although the resulting rates of follow-up were within the range reported in the literature, there is room for improvement, especially considering the monetary benefit that could be used on other diseases. Health systems and payers should work cooperatively to structure payment models to better incentivize CRC screenings.

Reviewing the Evidence that Polypectomy Prevents Cancer

Colonoscopic polypectomy is fundamental to effective prevention of colorectal cancer. Polypectomy reduces colorectal cancer incidence and mortality by altering the natural history and progression of precancerous precursor polyps. Epidemiologic data from the United States, where colorectal cancer rates have been steadily declining in parallel with screening efforts, provide indisputable evidence about the effectiveness of polypectomy. Randomized controlled trials of fecal occult blood tests and flexible sigmoidoscopy, and observational colonoscopy studies, provide additional support. Longitudinal studies have shown variable levels of protection after polypectomy, highlighting the central importance of high quality and adequate surveillance of higher-risk patients.

Effects of Colorectal Cancer Risk Factors on the Association Between Aspirin and Colorectal Cancer

BACKGROUND/AIM

We investigated the effect of aspirin on colorectal cancer (CRC) risk among subgroups of women with and without risk factors for CRC.

PATIENTS AND METHODS

Using data from the Women's Health Initiative, we estimated hazard ratios for CRC in association with aspirin use, with stratifications by cardiovascular disease (CVD) risk status, family history of CRC, and history of colorectal polypectomy.

RESULTS

Aspirin was associated with a lower risk of CRC among women with low/normal or high CVD-risk status; no family history of CRC; or a history of colonoscopy with polypectomy. Aspirin was not associated with CRC among women with a family history of CRC or a history of colonoscopy without polypectomy.

CONCLUSION

Aspirin was associated with a lower risk of CRC in women at all levels of CVD-risk, in those with a history of colonoscopy with polypectomy, and in those without a family history of CRC.

Surveillance of premalignant gastric lesions: a multicentre prospective cohort study from low incidence regions

OBJECTIVE

International guidelines recommend endoscopic surveillance of premalignant gastric lesions. However, the diagnostic yield and preventive effect require further study. We therefore aimed to assess the incidence of neoplastic progression and to assess the ability of various tests to identify patients most at risk for progression.

DESIGN

Patients from the Netherlands and Norway with a previous diagnosis of atrophic gastritis (AG), intestinal metaplasia (IM) or dysplasia were offered endoscopic surveillance. All histological specimens were assessed according to the updated Sydney classification and the operative link on gastric intestinal metaplasia (OLGIM) system. In addition, we measured serum pepsinogens (PG) and gastrin-17.

RESULTS

279 (mean age 57.9 years, SD 11.4, male/female 137/142) patients were included and underwent at least one surveillance endoscopy during follow-up. The mean follow-up time was 57 months (SD 36). Four subjects (1.4%) were diagnosed with high-grade adenoma/dysplasia or invasive neoplasia (ie, gastric cancer) during follow-up. Two of these patients were successfully treated with endoscopic submucosal dissection, while the other two underwent a total gastrectomy. Compared with patients with extended AG/IM (PGI/II≤3 and/or OGLIM stage III-IV), patients with limited AG/IM (PG I/II>3 and OLGIM stage 0-II) did not develop high-grade adenoma/dysplasia or invasive neoplasia during follow-up (p=0.02).

CONCLUSION

In a low gastric cancer incidence area, a surveillance programme can detect gastric cancer at an early curable stage with an overall risk of neoplastic progression of 0.3% per year. Use of serological markers in endoscopic surveillance programmes may improve risk stratification.

Long-term Risk of Colorectal Cancer and Related Deaths After a Colonoscopy With Normal Findings

Importance

Guidelines recommend a 10-year rescreening interval after a colonoscopy with normal findings (negative colonoscopy results), but evidence supporting this recommendation is limited.

Objective

To examine the long-term risks of colorectal cancer and colorectal cancer deaths after a negative colonoscopy result, in comparison with individuals unscreened, in a large, community-based setting.

Design, Setting, and Participants

A retrospective cohort study was conducted in an integrated health care delivery organization serving more than 4 million members across Northern California. A total of 1 251 318 average-risk screening-eligible patients (age 50-75 years) between January 1, 1998, and December 31, 2015, were included. The study was concluded on December 31, 2016.

Exposures

Screening was examined as a time-varying exposure; all participants contributed person-time unscreened until they were either screened or censored. If the screening received was a negative colonoscopy result, the participants contributed person-time in the negative colonoscopy results group until they were censored.

Main Outcomes and Measures

Using Cox proportional hazards regression models, the hazard ratios (HRs) for colorectal cancer and related deaths were calculated according to time since negative colonoscopy result (or since cohort entry for those unscreened). Hazard ratios were adjusted for age, sex, race/ethnicity, Charlson comorbidity score, and body mass index.

Results

Of the 1 251 318 patients, 613 692 were men (49.0%); mean age was 55.6 (7.0) years. Compared with the unscreened participants, those with a negative colonoscopy result had a reduced risk of colorectal cancer and related deaths throughout the more than 12-year follow-up period, and although reductions in risk were attenuated with increasing years of follow-up, there was a 46% lower risk of colorectal cancer (hazard ratio, 0.54; 95% CI, 0.31-0.94) and 88% lower risk of related deaths (hazard ratio, 0.12; 95% CI, 0.02-0.82) at the current guideline-recommended 10-year rescreening interval.

Conclusions and Relevance

A negative colonoscopy result in average-risk patients was associated with a lower risk of colorectal cancer and related deaths for more than 12 years after examination, compared with unscreened patients. Our study findings may be able to inform guidelines for rescreening after a negative colonoscopy result and future studies to evaluate the costs and benefits of earlier vs later rescreening intervals.

Barriers and Facilitators to Colorectal Cancer Screening Within a Hispanic Population

INTRODUCTION

Colorectal cancer (CRC) is the third leading cancer cause of death among US Hispanics. CRC screening among the Hispanic population is lower compared with non-Hispanic Whites.

METHOD

The purpose of this qualitative, exploratory study was to better understand the barriers and facilitators of CRC screening and preference for stool-based testing collection methods among the predominantly Hispanic population of El Paso, Texas. Nine focus groups were conducted by a trained bilingual facilitator with a moderator guide informed by the literature. Transcripts of the focus groups were entered into qualitative analysis software and a thematic network was developed.

RESULTS

Fifty-six participants were recruited: average age was 68.5 years, 58.9% were female, 98.2% were Hispanic, 87.5% had an annual income of less than $20,000, 58.9% had 9th grade education or less, 12.5% had a discount program, and 5.4% had no insurance. Barriers to CRC screening included cost, fear, and embarrassment. Facilitators to screening included in-person health education and physician recommendation. Participants preferred the hygienic nature of a stool test collected with a brush and bottle.

CONCLUSION

Overall, there was a lack of knowledge regarding CRC and significant barriers to CRC screening. A community-based CRC screening program was subsequently developed from our findings.

Is magnetic resonance imaging useful for the management of patients with rectal villous adenoma? A study of 45 consecutive patients treated by transanal endoscopic microsurgery

PURPOSE

Very few data are available about the clinical relevance of magnetic resonance (MR) imaging in preoperative evaluation of rectal villous adenoma. The aim is to evaluate the impact of MR imaging for the surgical management of rectal villous adenoma treated by transanal endoscopic microsurgery (TEM).

METHODS

All patients with histologically proven rectal villous tumours operated by TEM who had a preoperative MR imaging between 2009 and 2017 were retrospectively reviewed. All patients underwent TEM because preoperative evaluation suggested systematically usT0 or usT1 tumour. Pathological stage was blindly compared to preoperative MR imaging (location according to the anal verge and the peritoneal reflection, amount of circumferential involvement, tumour size and staging) and preoperative transrectal ultrasonography (TRUS) results.

RESULTS

Forty-five patients were included (24 men, mean age 65 ± 8 years) with TRUS data available only in 37. Pathologic results were pT0-pTis in 32, pT1 in 10 and pT2 in 3. TRUS diagnosed correctly 36/37 lesions (97%) and understaged one pT2 tumour. A significant correlation between TRUS and pathologic results was noted (r = 0.99; p = 0.01). MR imaging diagnosed correctly 19/42 pTis-T1 and 1/3 pT2 tumours (46%). Overstaging by MR imaging was noted in 25 cases (54%). No correlation between MR imaging and pathologic results was noted (r = 0.7; p = 0.3).

CONCLUSION

Preoperative evaluation of rectal villous adenoma is overstaged by MRI in more than half of the patients. This study suggests that the indication of local excision by TEM for rectal villous adenoma should be based on TRUS rather than on MRI.

Colorectal cancer death after adenoma removal in Scandinavia

OBJECTIVES

Improved understanding of the subsequent risk death from colorectal cancer (CRC) among individuals who had adenomas removed is needed. We aimed to quantify this risk using prospectively collected data from population-based cohorts.

MATERIALS AND METHODS

Using Norwegian and Swedish registries, a cohort of 90,864 individuals with colorectal adenomas removed between 1980 and 2013 was identified. Surveillance was only recommended for high-risk adenomas. The validity of the registry data did not allow classification into low- and high-risk adenomas. Virtually complete follow-up was achieved through linkage to nationwide registers. We calculated incidence-based standardised mortality ratios (SMRs) with 95% confidence intervals (CI).

RESULTS

The median follow-up was 7.2 years; 48,058 individuals were followed for more than 10 years. We observed 819 deaths (0.9%) from CRC and expected 731 CRC deaths (0.8%), corresponding to an absolute excess risk of 88 cases (0.1%) and a relative risk of 12% (SMR 1.12; 95%CI 1.05-1.20). The relative risk of CRC death following adenoma removal was slightly higher in Sweden (SMR 1.22; 95%CI 1.11-1.34) than in Norway (SMR 1.03; 95%CI 0.93-1.14), and higher in women (SMR 1.24; 95%CI 1.12-1.36) than in men (SMR 1.02; 95%CI 0.93-1.13). Among individuals with more than 10 years of follow-up, the estimates were similar to the overall cohort, absolute excess risk 0.1% (SMR 1.15; 95%CI 1.06-1.24).

CONCLUSION

The excess risk of CRC death following adenoma removal is small. Optimal surveillance recommendations should be tested in randomised trials.

Evaluation of the Effectiveness and Cost-Effectiveness of Personalized Surveillance After Colorectal Adenomatous Polypectomy

Lifetime risk of developing colorectal cancer is 5%, and 5-year survival at early stage is 92%. Individuals with precancerous lesions removed at primary screening are typically recommended surveillance colonoscopy. Because greater benefits are anticipated for those with higher risk of colorectal cancer, scope for risk-specific surveillance recommendations exists. This review assesses published cost-effectiveness estimates of postpolypectomy surveillance to consider the potential for personalized recommendations by risk group. Meta-analyses of incidence of advanced neoplasia postpolypectomy for low-risk cases were comparable to those without adenoma, with both rates under the lifetime risk of 5%. This group may not benefit from intensive surveillance, which risks unnecessary harm and inefficient use of often scarce colonoscopy capacity. Therefore, greater personalization through deintensified strategies for low-risk individuals could be beneficial. The potential for noninvasive testing, such as fecal immunochemical tests, combined with primary prevention or chemoprevention may reserve colonoscopy for targeted use in personalized risk-stratified surveillance. This review appraised evidence supporting a program of personalized surveillance in patients with colorectal adenoma according to risk group and compared the effectiveness of surveillance colonoscopy with alternative prevention strategies. It assessed trade-offs among costs, benefits, and adverse effects that must be considered in a decision to adopt or reject personalized surveillance.

Delivering a research-enabled multistakeholder partnership for enhanced patient care at a population level: The Northern Ireland Comprehensive Cancer Program

The last 20 years have seen significant advances in cancer care in Northern Ireland, leading to measureable improvements in patient outcomes. Crucial to this transformation has been an ethos that recognizes the primacy role of research in effecting heath care change. The authors' model of a cross‐sectoral partnership that unites patients, scientists, health care professionals, hospital trusts, bioindustry, and government agencies can be truly transformative, empowering tripartite clinical‐academic‐industry efforts that have already yielded significant benefit and will continue to inform strategy and its implementation going forward.

MicroRNAs as non-invasive screening biomarkers of colorectal cancer

Colorectal cancer is a major cause of cancer-associated deaths in the world. Early detection would be greatly enhanced if accurate and cost-effective diagnostic biomarkers for this disease were accessible. The development of such a blood test will evidently lower the screening costs in regards of colorectal cancer detection. Lately, it has been suggested that microRNA diagnostic biomarkers are feasible new screening methods for colorectal cancer. This review summarizes the diagnostic potential of circulating microRNA biomarkers in relation with colorectal cancer, as well as current methods to detect them.