Effects of metabolic syndrome and findings from baseline colonoscopies on occurrence of colorectal neoplasms

Adopting Non-invasive Approaches into Precision Colorectal Cancer Screening

Effective screening is essential to reducing CRC incidence and mortality by detecting the disease at early stages and identifying non-invasive precursors. While colonoscopy remains the most sensitive modality to visualize and remove neoplastic lesions thereby reducing CRC and the related death, its high cost and invasive nature limit its widespread use. The fecal immunochemical test (FIT), which offers a non-invasive alternative with higher public acceptance and comparable cost-effectiveness to colonoscopy, has become the preferred screening method in many regions. Newer non-invasive tests, such as multitarget stool DNA or RNA tests, have shown improved sensitivity for CRC and advanced adenomas, although their high costs and lower specificity present challenges for large-scale implementation. Blood-based circulating cell-free DNA test also offer promise but still require optimization to be cost-effective. The heterogeneity of the screening population further complicates the effectiveness of CRC screening programs. Variations in non-communicable disease risk factors, such as metabolic syndrome, lifestyle habits, and comorbidities, can significantly influence CRC risk and screening outcomes. Moreover, diverse screening behaviors, including inconsistent adherence to recommended screening intervals and the interchangeable use of different screening modalities, add complexity to achieving uniform effectiveness across populations. This variability underscores the need for personalized screening strategies that consider individual risk profiles and screening behaviors, as well as the application of cutting-edge technologies such as big data analytics, artificial intelligence, and digital twin approaches to evaluate its effectiveness. This article reviews the current CRC screening strategies, the advantages of non-invasive methods, and the potential of fecal hemoglobin concentration, to tailor screening intervals and improve risk stratification. It also discusses the emerging role of real-world data and advanced technologies in enhancing CRC screening accuracy and effectiveness, particularly in complex real-world scenarios where traditional methods may fall short. Before novel non-invasive approaches, such as ctDNA tests or polygenic risk scores, are validated and proven cost-effective, exploring the clinical utility of FIT and its quantitative measurement in both screening and surveillance by integrating real-world clinical big data seems a feasible direction for achieving sustained development in population screening.

Metabolic syndrome and risk of colorectal cancer: A Mendelian randomization study

Background

Observational studies have previously demonstrated a significant relationship among both metabolic syndrome (Mets) and colorectal cancer (CRC). Whether there is a causal link remains controversial.

Objective

To clarify whether Mets and their components have a causal effect on colorectal cancer, we have carried out a bidirectional Mendelian randomization analysis (MR).

Methods

This study started from genome-wide association data for Mets and its 5 components (hypertension, waist circumference, fasting blood glucose, serum triglycerides, and serum high-density lipoprotein cholesterol) and colorectal cancer. Mendelian randomization (MR) techniques were used in the study to examine their associations.

Results

After Benjamini-Hochberg multiple corrections, genetically predicted significant causal link exists between WC (waist circumference) and CRC. The OR was 1.35 (95 % CI: 1.08-1.69; p = 0.0096). Other Mets components (HBP, FBG, TG, HDL), on the other hand, found no evidence of a genetic link between CRC and Mets. In addition, MR results showed that CRC was not causally related to either Mets or the components. We get the same result in the validated dataset.

Conclusion

According to the bidirectional MR investigation shows a significant causal relationship among obesity and CRC in the Mets component but no causal relationship in the opposite direction.

Beyond colonoscopy: Physical activity as a viable adjunct to prevent colorectal cancer

Colorectal cancer (CRC) is a common cancer with an increasing incidence worldwide. The implementation of a mass screening program has been proven effective in reducing the global burden of CRC, but its effectiveness is not ideal and some metabolic derangements and lifestyle factors were reported to be attributable for such a deficit. Implementing positive lifestyle intervention as primary prevention therefore becomes critical because colorectal carcinogenesis can be promoted by several lifestyle factors, such as a lack of physical activity. Herein, we review the current evidence on the association and possible mechanisms between physical activity and CRC carcinogenesis. In addition, since CRC prevention heavily relies on resection of precancerous polyps and subsequent surveillance by colonoscopy, this review will also explore the impact of physical activity on populations with different colorectal polyp risks and its potential adjunct role in altering surveillance outcomes.

Third Asia-Pacific consensus recommendations on colorectal cancer screening and postpolypectomy surveillance

The Asia-Pacific region has the largest number of cases of colorectal cancer (CRC) and one of the highest levels of mortality due to this condition in the world. Since the publishing of two consensus recommendations in 2008 and 2015, significant advancements have been made in our knowledge of epidemiology, pathology and the natural history of the adenoma-carcinoma progression. Based on the most updated epidemiological and clinical studies in this region, considering literature from international studies, and adopting the modified Delphi process, the Asia-Pacific Working Group on Colorectal Cancer Screening has updated and revised their recommendations on (1) screening methods and preferred strategies; (2) age for starting and terminating screening for CRC; (3) screening for individuals with a family history of CRC or advanced adenoma; (4) surveillance for those with adenomas; (5) screening and surveillance for sessile serrated lesions and (6) quality assurance of screening programmes. Thirteen countries/regions in the Asia-Pacific region were represented in this exercise. International advisors from North America and Europe were invited to participate.

Incidence of colorectal cancer at different screening intervals after index colonoscopy and post-polypectomy: a meta-analysis of 811,181 participants

OBJECTIVES

To examine the evidence on the incidence of colorectal cancers (CRCs) at a follow-up screening colonoscopy (after index colonoscopy and post-polypectomy) in individuals with no adenoma, low-risk adenomas, and high-risk adenomas.

METHODS

We included studies reporting the incidence of CRCs at different screening intervals after index colonoscopy and post-polypectomy. The main outcome was pooled cumulative incidence rate of CRCs stratified by intervals of 3, 5, 10, and >10 years.

RESULTS

Fourteen studies with 811,181 participants were analyzed, including 10 multicenter studies and 3 national CRC screening programs. The cumulative incidence of CRCs was 0.63% (95% confidence interval [CI]: 0.30, 0.97) in the high-risk-adenoma group at 3 years, 0.37% (95% CI: 0.13, 0.61) and 0.67% (95% CI: 0.36, 0.99) in the low-risk-adenoma group at 5 and 10 years, respectively, and 0.32% (95% CI: 0.20, 0.45) and 0.50% (95% CI: 0.30, 0.69) in the no-adenoma-group at 10 and >10 years, respectively.

CONCLUSION

This meta-analysis summarizes the results of colonoscopy surveillance programs with detailed data support for different screening intervals. The data on date suggest that reasonable surveillance intervals are within 3 years for the high-risk-adenoma group, 5-10 years for the low-risk-adenoma group, and ≥10 years for the no-adenoma group.

Implementing precision medicine in endoscopy practice

In contrast to the "one-size-fits-all" approach, precision medicine focuses on providing health care tailored to individual variabilities. Implementing precision medicine in endoscopy practice involves selecting the appropriate procedures among the endoscopic armamentarium in the diagnosis and management of patients in a logical sequence, jointly considering the pretest probabilities of possible diagnoses, patients' comorbidities and preference, and risk-benefit ratio of the individual procedures given the clinical scenario. The aim of this review is to summarize evidence-supported strategies and measures that may enhance precision medicine in general endoscopy practice.

Systematic review and meta-analysis: Associations between metabolic syndrome and colorectal neoplasia outcomes

AIM

Metabolic syndrome (MetS) is a cluster of factors including obesity, hypertension, diabetes, hypercholesterolemia and hyperlipidaemia. It has been associated with an increased risk of colorectal neoplasia. This systematic review and meta-analysis assessed the association between MetS and (i) recurrence of adenomas or occurrence of CRC in patients with prior adenomas, and (ii) survival in patients with CRC.

METHOD

MEDLINE, Embase, Scopus and Web of Science were searched up to 22 November 2019. Two authors independently conducted title and abstract screening; full text of eligible studies was evaluated. Where ≥3 studies reported effect measures for a specific outcome, meta-analysis using random effects model was conducted. I² was used to assess between-study heterogeneity. Quality appraisal was undertaken with the Newcastle-Ottawa Score.

RESULTS

The search identified 1,764 articles, 55 underwent full text screening, resulting in a total of 15 eligible studies. Five studies reported on metachronous neoplasia, with differing outcomes precluded a meta-analysis. No consistent relationship between MetS and metachronous neoplasia was found. Ten studies reported on survival outcomes. MetS was associated with poorer CRC-specific survival (HR = 1.8, 95% CI: 1.04-3.12, I²  = 92.7%, n = 3). Progression-free survival was also worse but this did not reach statistical significance (HR = 1.12, 95% CI: 0.89-1.42, I²  = 85.6%, n = 3). There was no association with overall survival (HR = 1.04, 95% CI: 0.94-1.15, I²  = 43.7%, n = 7). Significant heterogeneity was present but subgroup analysis did not account for this.

CONCLUSION

MetS is associated with poorer CRC-specific survival, but evidence is inconsistent on metachronous neoplasia. Further research is warranted to better understand the impact of MetS on the adenoma-carcinoma pathway.

Active exercise after polypectomy reduces the risk of metachronous advanced colorectal neoplasm

BACKGROUND AND STUDY AIMS

Exercise is associated with a lower risk of colorectal neoplasm but its association with metachronous advanced colorectal neoplasm development after polypectomy remains unclear. We aimed to investigate associations between subjects' exercise habits and the risk of metachronous advanced colorectal neoplasm.

PATIENTS AND METHODS

This study analyzed subjects older than 40 years who received screening colonoscopy with polypectomy and surveillance colonoscopy between January 2009 and December 2016. All participants completed a standard questionnaire containing exercise habits before surveillance colonoscopy. Subjects' exercise habits were quantified as weekly exercise amounts (metabolic equivalents of task-day/week) and dichotomized (active/sedentary exercise habit) using averages as the cut-off point. The associations between incidence of metachronous advanced colorectal neoplasm and exercise habits were evaluated using Kaplan-Meier analysis and Cox regression models.

RESULTS

A total of 1820 subjects comprised the study cohort and 86 (4.73%) of them developed metachronous advanced colorectal neoplasm during the surveillance period. An active exercise habit after polypectomy was associated with a lower risk of metachronous advanced colorectal neoplasm (adjusted hazard ratio [aHR] 0.57, 95% confidence interval [CI] 0.35-0.91). Furthermore, this protective effect from exercise was specific for subjects having advanced neoplasm at screening colonoscopy (aHR 0.32, 95% CI 0.11-0.94).

CONCLUSIONS

An active exercise habit after polypectomy, a surrogate for a more active lifestyle, is associated with a lower risk for developing metachronous advanced colorectal neoplasm. A positive lifestyle modification, such as maintaining/establishing an active exercise habit, should be advised after polypectomy, especially for those with advanced colorectal neoplasm during screening.

The influence of the surveillance time interval on the risk of advanced neoplasia after non-advanced adenoma removal

OBJECTIVES

To investigate the incidence of advanced neoplasia (colorectal cancer or advanced adenoma) at surveillance colonoscopy following removal of non-advanced adenoma; to determine whether the time interval before surveillance colonoscopy influences the likelihood of advanced neoplasia.

DESIGN

Retrospective cohort study.

SETTING, PARTICIPANTS

Patients enrolled in a South Australian surveillance colonoscopy program with findings of non-advanced adenoma during 1999-2016 who subsequently underwent surveillance colonoscopy.

MAIN OUTCOME MEASURES

Incidence of advanced neoplasia at follow-up surveillance colonoscopy.

RESULTS

Advanced neoplasia was detected in 169 of 965 eligible surveillance colonoscopies (18%) for 904 unique patients (median age, 62.0 years; interquartile range [IQR], 54.0-69.0 years), of whom 570 were men (59.1%). The median interval between the initial and surveillance procedures was 5.2 years (IQR, 4.4-6.0 years; range, 2.0-14 years). Factors associated with increased risk of advanced neoplasia at follow-up included age (per year: odds ratio [OR], 1.03; 95% CI, 1.01-1.05), prior history of adenoma (OR, 1.48; 95% CI, 1.01-2.15), two non-advanced adenomas identified at baseline procedure (v one: OR, 1.74; 95% CI, 1.18-2.57), and time to surveillance colonoscopy (OR, 1.21; 95% CI, 1.08-1.37). The estimated incidence of advanced neoplasia was 19% five years after non-advanced adenoma removal, and 30% at ten years.

CONCLUSIONS

Increasing the surveillance colonoscopy interval beyond five years after removal of non-advanced adenoma increases the risk of detection of advanced neoplasia at follow-up colonoscopy.

Age, male sex, smoking and metabolic syndrome as risk factors of advanced colorectal neoplasia for fecal immunochemical test negative patients

BACKGROUND

Fecal immunochemical test (FIT) is worldwide strategy for colorectal cancer screening. The subjects with negative FIT still have the risk of an advanced colorectal neoplasia (AN), including adenoma with villous histology, high grade dysplasia or larger than 1 cm in size, or adenocarcinoma. The study determined the risk factors associated with AN in FIT-negative subjects.

METHODS

The study included asymptomatic subjects who received health checkup colonoscopy and have provided FIT study within 6 months prior to colonoscopy. The risk factors to have AN in cases with negative FIT were analyzed. The numbers of colonoscopies needed to detect one AN were calculated for the subjects with different risk factors.

RESULTS

There were 1411 cases, 85 with positive FIT and 1326 with negative FIT within 6 months before colonoscopy. In FIT positive and FIT negative cases, 45.9% and 34.6% were found to have colorectal adenoma, while 20.2% and 4.6% had AN, respectively. The univariate and multivariate logistic regression analyses showed that age more than 50 years old, male sex, smoking history and metabolic syndrome were the significant risk factors to have AN in the FIT negative cases. For cases with negative FIT to have these risk factors, the number of colonoscopies needed to detect one AN was 3.7, lower than 4.5 of the cases with positive FIT.

CONCLUSION

For the cases with negative FIT, colonoscopy screening should be considered for those male patients over 50 years old, with a history of smoking and metabolic syndrome to detect AN.

Metabolically Healthy Obesity Is Associated with an Increased Risk of Colorectal Adenoma Occurrence Diagnosed by Surveillance Colonoscopy

Background/Aims

The risk of recurrence of colorectal adenoma among obese individuals without metabolic abnormalities or in those with metabolically healthy obesity is largely unexplored. Therefore, we longitudinally investigated the risk of adenoma occurrence in individuals undergoing surveillance colonoscopy according to metabolic status and obesity.

Methods

This retrospective cohort study included 16,872 Korean adults who underwent their first screening colonoscopy between 2003 and 2012 and who then underwent follow-up colonoscopy until 2017. Participants were categorized into a metabolically healthy nonobese group (reference group), a metabolically healthy obese group, a metabolically abnormal nonobese group, and a metabolically abnormal obese group. Hazard ratios (HRs) for adenoma recurrence compared to the reference group were calculated in each group.

Results

During a median follow-up duration of 47.3 months (interquartile range, 35.6 to 58.9 months), 3,673 (21.8%) and 292 (1.73%) participants developed adenoma and advanced adenoma, respectively. When age, sex, smoking, alcohol consumption, family history of colorectal cancer, and baseline adenoma risk were adjusted, the risk of adenoma recurrence was increased in metabolically healthy obese individuals (HR, 1.33; 95% confidence interval [CI], 1.12 to 1.57) and metabolically abnormal obese individuals (HR, 1.18; 95% CI, 1.08 to 1.30) but not in metabolically abnormal nonobese individuals (HR, 1.03; 95% CI, 0.94 to 1.13).

Conclusions

In this study, metabolically healthy obese individuals and metabolically abnormal obese individuals exhibited increased risks of occurrence of colorectal adenoma diagnosed by surveillance colonoscopy. This finding implies that obesity itself, even without metabolic abnormalities, is associated with an increased risk of adenoma recurrence. ^{(Gut Liver} 2021;15-390⁾

Risk of Colorectal Cancer and Cancer Related Mortality After Detection of Low-risk or High-risk Adenomas, Compared With No Adenoma, at Index Colonoscopy: A Systematic Review and Meta-analysis

BACKGROUND & AIMS

The risk of metachronous colorectal cancer (CRC) among patients with no adenomas, low-risk adenomas (LRAs), or high-risk adenomas (HRAs), detected at index colonoscopy, is unclear. We performed a systematic review and meta-analysis to compare incidence rates of metachronous CRC and CRC-related mortality after a baseline colonoscopy for each group.

METHODS

We searched the PubMed, Embase, Google Scholar, and Cochrane databases for studies that reported the incidence of CRC and adenoma characteristics after colonoscopy. The primary outcome was odds of metachronous CRC and CRC-related mortality per 10,000 person-years of follow-up after baseline colonoscopy for all the groups.

RESULTS

Our final analysis included 12 studies with 510,019 patients (mean age, 59.2 ± 2.6 years; 55% male; mean duration of follow up, 8.5 ± 3.3 years). The incidence of CRC per 10,000 person-years was marginally higher for patients with LRAs compared to those with no adenomas (4.5 vs 3.4; odds ratio [OR], 1.26; 95% CI, 1.06-1.51; I²=0), but significantly higher for patients with HRAs compared to those with no adenoma ( 13.8 vs 3.4; odds ratio [OR], 2.92; 95% CI, 2.31-3.69; I²=0 ) and patients with HRAs compared to LRAs (13.81 vs 4.5; OR, 2.35; 95% CI, 1.72-3.20; I²=55%). However, the CRC-related mortality per 10,000 person-years did not differ significantly for patients with LRAs compared to no adenomas (OR, 1.15; 95% CI, 0.76-1.74; I²=0) but was significantly higher in persons with HRAs compared with LRAs (OR, 2.48; 95% CI, 1.30-4.75; I²=38%) and no adenomas (OR, 2.69; 95% CI, 1.87-3.87; I²=0).

CONCLUSIONS

The results of this systematic review and meta-analysis demonstrate that the risk of metachronous CRC and mortality is significantly higher for patients with HRAs, but this risk is very low in patients with LRAs, comparable to patients with no adenomas. Follow-up of patients with LRAs detected at index colonoscopy should be the same as for persons with no adenomas.

Risk factors of advanced metachronous neoplasms in surveillance after colon cancer resection

BACKGROUND/AIMS

Regular surveillance colonoscopy after colon cancer resection is recommended for detecting metachronous adenoma and cancer. However, risk factors for metachronous neoplasms have not been fully evaluated. We aimed to assess risk factors for advanced metachronous neoplasms during surveillance colonoscopy after colon cancer resection.

METHODS

Patients who underwent curative colectomy for nonmetastatic colon cancer between January 2002 and December 2012 were evaluated and followed up to December 2017.

RESULTS

A total of 293 patients were enrolled in this study. Among these, 179 (61.1%) were male, and the mean age was 63.2 ± 10.4 years. On perioperative clearing colonoscopy, synchronous high-risk adenomas (number ≥ 3, size ≥ 10 mm, high-grade dysplasia, villous histology, and serrated adenoma ≥ 10 mm) were detected in 95 patients (32.4%), and they were significantly associated with male sex, old age (≥ 65 years), current alcohol consumption, and current smoking (p < 0.05). During the follow-up period (mean 74.4 ± 36.4 months), advanced metachronous neoplasms were found in 45 patients (15.4%), including metachronous cancer in four (1.4%). In multivariate analysis, distal colon cancer (distal-to-splenic flexure; odds ratio [OR], 4.402; 95% confidence interval [CI], 1.658 to 11.689; p = 0.003), synchronous highrisk adenomas (OR, 3.225; 95% CI, 1.503 to 6.918; p = 0.003), and hypertension (OR, 2.270; 95% CI, 1.058 to 4.874; p = 0.035) were significant risk factors for advanced metachronous neoplasms.

CONCLUSION

During surveillance after curative colon cancer resection, patients with distal colon cancer, synchronous high-risk adenomas, and hypertension may need meticulous follow-up to improve overall outcomes.

Skeletal muscle mass and risk of advanced adenoma in surveillance colonoscopy

BACKGROUND AND AIM

Sarcopenia has been suggested to be associated with chronic inflammation and insulin resistance. This study aimed to evaluate whether low muscle mass is associated with the incidence and recurrence of advanced colorectal adenoma.

METHODS

We conducted a cohort study including 14 701 participants who underwent first-time screening colonoscopy between 2003 and 2012 and follow-up colonoscopy until 2017. Skeletal muscle mass was measured using a bioelectrical impedance analyzer and divided by body weight to calculate the skeletal muscle mass index (SMI).

RESULTS

During a median 47 (interquartile range, 35-58) months of follow-up, overall and advanced adenoma developed in 2988 (20.3%) and 207 (1.41%) participants, respectively. In multivariate analysis using models adjusted for baseline adenoma risk, lifestyle factors, markers for insulin resistance and chronic inflammation, and metabolic syndrome, decreasing SMI quartiles were associated with increased risk of occurrence of advanced adenoma and overall adenoma. The adjusted hazard ratios (95% confidence intervals) comparing SMI quartiles 3, 2, and 1 to quartile 4 were 1.57 (1.03-2.41), 1.22 (0.78-1.92), and 1.77 (1.13-2.76), respectively, for advanced adenoma (P for trend = 0.049) and 1.05 (0.95-1.17), 1.09 (0.98-1.21), and 1.26 (1.13-1.41), respectively, for overall adenoma (P for trend < 0.001).

CONCLUSIONS

In this large cohort with long-term colonoscopy follow-up, low relative muscle mass was associated with increased risk of occurrence of advanced adenoma and overall adenoma at follow-up colonoscopy, independent of metabolic and inflammatory markers. Timely and thorough surveillance colonoscopy may be emphasized in such populations.

Higher risk of advanced histology in adenoma less than 10 mm in fecal immunochemical test screening: Implication for management

BACKGROUND AND AIM

Whether diminutive or small adenomas detected by fecal immunochemical tests (FITs) are associated with a higher risk of advanced histology remains unknown. We investigated the prevalence of advanced histology in diminutive and small adenomas detected by FIT and compared with that detected by colonoscopy screening.

METHODS

We prospectively compared 1860 FIT-positive patients (FIT-positive cohort) and 6691 average-risk patients (screening colonoscopy cohort). Both groups underwent colonoscopies and were shown to have neoplastic lesions. The prevalence of advanced histology was determined, as was the associations with size and FIT positivity.

RESULTS

We analyzed 3920 neoplastic lesions from the FIT-positive cohort and 9789 neoplastic lesions from the screening colonoscopy cohort. Eighty (4.3%) diminutive lesions in FIT-positive cohort had advanced histology but without any invasive cancer. Twenty-one patients in the FIT-positive cohort and 49 in the screening colonoscopy cohort with diminutive adenomas displayed advanced histology (3.5% vs 1.2%; adjusted odds ratio [aOR] = 2.99, 95% confidence interval [CI]: 1.77-5.06). Sixteen patients in the FIT-positive cohort (2.7%) with diminutive adenomas might have changed the surveillance interval if a resect-and-discard strategy was applied, with a higher likelihood compared with the screening colonoscopy cohort (aOR = 2.76, 95% CI: 1.53-4.99).

CONCLUSIONS

Fecal immunochemical test screening detected more diminutive and small adenomas with advanced histology compared with colonoscopy screening. Its impact on current management of diminutive polyp is limited.

Outcomes at follow-up of negative colonoscopy in average risk population: systematic review and meta-analysis

OBJECTIVE

To review and summarise the evidence on the prevalence of colorectal adenomas and cancers at a follow-up screening colonoscopy after negative index colonoscopy, stratified by interval between examinations and by sex.

DESIGN

Systematic review and meta-analysis of all available studies.

DATA SOURCES

PubMed, Web of Science, and Embase. Two investigators independently extracted characteristics and results of identified studies and performed standardised quality ratings.

ELIGIBILITY CRITERIA

Studies assessing the outcome of a follow-up colonoscopy among participants at average risk for colorectal cancer with a negative previous colonoscopy (no adenomas).

RESULTS

28 studies were identified, including 22 cohort studies, five cross sectional studies, and one case-control study. Findings for an interval between colonoscopies of one to five, five to 10, and more than 10 years were reported by 17, 16, and three studies, respectively. Summary estimates of prevalences of any neoplasm were 20.7% (95% confidence interval 15.8% to 25.5%), 23.0% (18.0% to 28.0%), and 21.9% (14.9% to 29.0%) for one to five, five to 10, and more than 10 years between colonoscopies. Corresponding summary estimates of prevalences of any advanced neoplasm were 2.8% (2.0% to 3.7%), 3.2% (2.2% to 4.1%), and 7.0% (5.3% to 8.7%). Seven studies also reported findings stratified by sex. Summary estimates stratified by interval and sex were consistently higher for men than for women.

CONCLUSIONS

Although detection of any neoplasms was observed in more than 20% of participants within five years of a negative screening colonoscopy, detection of advanced neoplasms within 10 years was rare. Our findings suggest that 10 year intervals for colonoscopy screening after a negative colonoscopy, as currently recommended, may be adequate, but more studies are needed to strengthen the empirical basis for pertinent recommendations and to investigate even longer intervals.

STUDY REGISTRATION

Prospero CRD42019127842.

Risk factors of traditional serrated adenoma and clinicopathologic characteristics of synchronous conventional adenoma

BACKGROUND AND AIMS

Traditional serrated adenoma (TSA) is rare and known to have a malignant potential. We aimed to investigate the prevalence and risk factors of TSA and compare the characteristics of synchronous conventional adenoma (AD) in patients with TSA with those of AD in patients with AD only.

METHODS

We reviewed medical records of 31,932 healthy subjects who underwent screening colonoscopy at a single hospital between 2012 and 2017.

RESULTS

TSA was observed in 116 patients (.4%). Among them, 47 patients (40.5%) had TSA only and 69 patients (59.5%) had synchronous AD. Multivariable analysis showed independent risk factors for TSA to include age ≥50 years (odds ratio [OR], 3.34; 95% confidence interval [CI], 1.72-6.49; P < .001), hypertension (OR, 2.07; 95% CI, 1.09-3.92; P = .026), and current smoking (OR, 2.58; 95% CI, 1.28-5.23; P = .008). There were significantly more ADs (2.5 ± 2.0 vs 1.8 ± 1.6, P = .009) and ADs were of larger size (6.7 ± 5.0 vs 5.3 ± 3.6 mm, P = .027) in TSA patients than in AD-only patients. Furthermore, advanced adenoma and high-risk adenoma were more frequently observed in TSA patients than in AD-only patients (24.2% vs 11.2%, P = .002; 43.5% vs 23.6%, P < .001).

CONCLUSIONS

The prevalence of TSA in healthy adults was .4%. Age ≥50 years, hypertension, and current smoking may be risk factors of TSA. Synchronous AD is often observed with TSA and may show more advanced features than those in AD-only patients.

Comparative Evaluation of Colon Cancer Specific Antigen-2 Test and Chromocolonoscopy for Early Detection of Egyptian Patients with Colorectal Cancer

Background: Effective screening of colorectal cancer (CRC) in early stage could reduce the advancement of CRC and therefore mortality. Effective screening is based on either stool dependent tests or colon dependent examination.

Aims: The aim of the study was a comparative evaluation of chromocolonoscopy and Colon Cancer-Specific Antigen-2 test for early detection of colorectal cancer in Egyptian patients.

Methods: This case control study was carried out on 55 patients classified into 3 groups: Group I consisted of twenty patients with precancerous lesions detected by colonoscopy, Group II consisted of twenty patients diagnosed with colorectal cancer and Group III consisted of fifteen individuals (who underwent colonoscopy for other indications) as a control group. All the subjects were subjected to measure occult blood in the stool, measurement of Colon Cancer-Specific Antigen-2 level in serum and tissue and chromo colonoscopy using Indigo Carmine stain.

Results: In group II, there was a statistically significant increase in CCSA2 in serum as compared to the other 2 groups. Cutoff >11.3 CCSA2 in serum showed 65% sensitivity, 85% specificity, 81.2% PPV, 70.8% NPV and 70.3% accuracy in the differentiation of group II with cancer colon from group I with premalignant colonic lesions. A cutoff > 9.1 CCSA2 in serum showed 95% sensitivity, 46.67% specificity, 70.4% PPV, 87.5% NPV and 73.5% accuracy in differentiating group II with cancer colon from normal controls (group III).

Conclusion: CCSA-2 level in serum was significantly higher in cancer colon. Chromoendoscopy has a role in the detection of polyps, both neoplastic and non-neoplastic.

Alcohol consumption is associated with the risk of developing colorectal neoplasia: Propensity score matching analysis

Although alcohol intake is known to be associated with the development of colorectal cancer, the effect of alcohol consumption on the development of colorectal neoplasm (CRN) is unclear. We performed a retrospective cohort analysis with 1 to 1 propensity score matching in a single center of Korea. Among 1,448 patients who underwent index and surveillance colonoscopy, 210 matched pairs were analyzed. The 5-year cumulative occurrence of overall CRN after index colonoscopy was higher in the significant alcohol consumption group (defined as alcohol consumption more than 30 g/day in men and 20 g/day in women) (vs. without significant alcohol consumption group) (40% vs. 27.6%, p = 0.004). Significant alcohol consumption increased the development of overall CRN (adjusted hazard ratio [aHR]: 1.86, 95% confidence interval [CI]: 1.28–2.70, p = 0.001) at surveillance colonoscopy. However, this effect was not valid on the development of advanced CRN. In subgroup analysis considering the risk classification of index colonoscopy, significant alcohol consumption increased the overall CRN development at surveillance colonoscopy in the normal group (patients with no detected adenoma in the index colonoscopy) (aHR: 1.90, 95% CI: 1.16–3.13, p = 0.01). Alcohol consumption habits should be considered in optimizing time intervals of surveillance colonoscopy.

Elucidating bidirectional relationship between metabolic syndrome and elevated faecal haemoglobin concentration: a Taiwanese community-based cohort study

OBJECTIVES

To elucidate the bidirectional temporal relationship between elevated faecal haemoglobin (f-Hb) concentration and metabolic syndrome (MetS).

DESIGN

A longitudinal cohort study was conducted by utilising data on community-based periodical screening for colorectal cancer with faecal immunochemical test (FIT) and health check-up for MetS.

SETTING

Population-based organised integrated service screening in Keelung city, Taiwan.

PARTICIPANTS

We enrolled a total of 62,293 community residents aged 40-79 years.

MAIN OUTCOMES AND MEASURES

Bidirectional outcomes of FIT-positive and MetS were measured.

RESULTS

The presence of MetS at baseline led to a statistically significant 31% elevated risk of being incident FIT-positive (adjusted HR, (aHR)=1.31, 95% CI: 1.14 to 1.51) whereas the effect of those with FIT-positive at baseline on incident MetS was not statistically significant (aHR=1.06, 95% CI: 0.89 to 1.25) after adjusting for relevant confounders. Such an effect was particularly noted for three individual components (abnormal waist circumference, higher fasting plasma glucose and lower high-density lipoprotein).

CONCLUSIONS

Our finding on the presence of MetS before FIT-positive based on bidirectional relationship assessment suggests the control of MetS may contribute to reducing the risk of colorectal neoplasia through the early surveillance of f-Hb. However, such a temporal epidemiological finding still needs to be verified by using other external data.

Metabolic syndrome is a risk factor for colorectal adenoma and cancer: a study in a White population using the harmonized criteria

BACKGROUND

Metabolic syndrome (MetS) has been associated with colorectal adenomas and cancer. However, MetS definitions have changed over time, leading to a heterogeneity of patients included in previous studies and a substantial inextensibility of observations across time or eastern and western populations. Our aim was to evaluate the association of 'harmonized' criteria-defined MetS and its individual components with colorectal neoplasia and cancer in a western population.

METHODS

In this multicenter, cross-sectional study, we prospectively evaluated consecutive outpatients who underwent open-access colonoscopy over a 3-month period. MetS was diagnosed according to the 2009 'harmonized' criteria.

RESULTS

Out of 5707 patients enrolled, we found 213 cancers (3.7%), 1614 polyps (28.3%), 240 nonpolypoid lesions (4.2%), 95 laterally spreading tumors (1.6%). Polyps presented histological low-grade dysplasia in 72.9% of samples, while in 9.8%, high-grade dysplasia or in situ carcinoma was present; dysplasia rates for nonpolypoid lesions were 66.2% (low-grade) and 2.9% (high-grade/in situ carcinoma), while for laterally spreading tumors, 29.6% and 37%, respectively. Overall, MetS prevalence was 41.6%. MetS correlated with both adenomas [odds ratio (OR): 1.76, 95% confidence interval (CI) 1.54-2.00] and cancer (OR: 1.92, 95% CI 1.42-2.58). MetS was the only risk factor for such colonic lesions in subjects younger than 50 years. For all colonic neoplasia, we found MetS and not its individual components to be significantly associated.

CONCLUSIONS

MetS is risk factor for cancer and adenoma in Whites, especially when younger than 50 years. MetS patients might be considered as a high-risk population also in colorectal cancer screening programs.

Visceral obesity as a risk factor for colorectal adenoma occurrence in surveillance colonoscopy

BACKGROUND AND AIMS

The aim of this study was to examine the prospective association between visceral obesity and the incidence and recurrence of colorectal adenoma.

METHODS

We conducted a cohort study involving 2244 participants between 2006 and 2007. The study participants were prospectively followed until 2014 according to the initial colonoscopy and histopathology findings. Incident and recurrent colorectal adenoma groups were defined as individuals with a positive follow-up colonoscopy result from the normal results and adenoma groups, respectively, at the baseline colonoscopy.

RESULTS

Among the 1163 patients (51.8%) who received a follow-up colonoscopy, 509 (43.8%) and 654 (56.2%) were grouped into the normal and adenoma cohorts. Colorectal adenomas occurred in 592 patients (50.9%) during the median period of 43 months, with an incident adenoma prevalence of 39.1% and a recurrent adenoma prevalence of 60.1%. An increase in the visceral adipose tissue (VAT) area was associated with a higher incidence of adenoma (highest quintile vs lowest quintile of the VAT hazard ratios [HRs], 2.16; 95% confidence interval [CI], 1.26-3.71; HR 1.32 [per 1-standard deviation]; 95% CI, 1.10-1.60) in the multivariable analysis. Increases in body mass index and waist circumference were associated with recurrent adenomas (HR 1.33 [per 1 kg/m²], 95% CI, 1.18-1.46; HR 1.04 [per 1 cm], 95% CI, 1.01-1.07, respectively) in the multivariate analysis.

CONCLUSION

A higher VAT area was dose-dependently associated with a higher risk of incident adenoma. Furthermore, increases in body mass index and waist circumference as surrogate markers of abdominal obesity were associated with a higher risk of recurrent adenoma.

Identification of risk factors for neoplastic colonic polyps in young adults with bloody stool in comparison with those without symptom

BACKGROUND AND AIMS

The incidence and disease burden of colorectal cancer (CRC) in young adults were increasing. However, there was a dearth of advice on how to identify young population at risk for neoplastic colonic polyps (NCPs) and CRC. We aimed to identify risk factors for NCPs and CRC in young adults presenting with bloody stool.

METHODS

A total of 1496 subjects younger than 40 years old who underwent colonoscopy due to bloody stool from 2005 to 2014 were enrolled in this retrospective study as the study group, and 1481 age-matched and gender-matched asymptomatic subjects who underwent colonoscopy for health checkup from 2011 to 2016 were enrolled as the control group at a tertiary center hospital.

RESULTS

Multivariate analysis results showed that increasing age (odds ratio [OR] = 1.11, 95% confidence interval [CI]: 1.07-1.15, P < 0.001), higher body mass index (BMI) (OR = 1.07, 95%CI: 1.03-1.12, P = 0.001), diabetes mellitus (OR = 2.80, 95%CI: 1.06-7.42, P = 0.038), and positive family history of CRC (OR = 13.28, 95%CI: 5.70-30.97, P < 0.001) were identified as independent risk factors for NCPs in study group. The best cut-off values by receiver operating characteristic curve for age and BMI were 32 years old and 24.8 kg/m² , respectively. More risk factors were associated with the higher risk for NCPs (OR = 2.17 every increasing one risk factor, P < 0.001). In the control group, no independent risk factors were identified.

CONCLUSIONS

Adults aged ≤ 40 years with bloody stool who had increasing age (> 32 years old), higher BMI (> 24.8 kg/m² ), diabetes mellitus, and positive family history of CRC had a higher detection rate of NCPs and CRC.

Distinct Metabolic Profiles are Associated with Colorectal Adenomas and Serrated Polyps

OBJECTIVE

Prevention of colorectal cancer (CRC) by colonoscopy is recommended according to age and personal/familial history. Metabolic alterations are associated with colorectal adenomas, but data are scarce regarding serrated polyps and advanced polyps. The aim of this study was to evaluate the association between metabolic alterations and colorectal polyp type and advanced polyps.

METHODS

A case-control study was conducted among consecutive subjects, 40 to 70 years old, who underwent screening/diagnostic colonoscopy from 2010 to 2015. Subjects who were treated for diabetes, who had a family/personal history of CRC, and who were at high risk for CRC were excluded. Participants underwent anthropometric, laboratory, and ultrasonographic evaluations and a medical and lifestyle interview. Polyps were histologically classified as adenomatous or serrated polyps and divided into advanced and non-advanced categories.

RESULTS

The study included 828 participants (58.4 ± 6.6 years, 50.4% men). Abdominal obesity (odds ratio [OR] = 1.67, 95% CI: 1.20-2.30), hypertension (OR = 1.47, 95% CI: 1.03-2.09), and a high glycosylated hemoglobin percentage (HbA1c%) (OR = 1.57, 95% CI: 1.06-2.34) were independently associated with colorectal adenomas, whereas a high triglyceride to high-density lipoprotein cholesterol (TG/HDL) ratio was independently associated with serrated polyps (OR = 2.31, 95% CI: 1.32-4.03). A combination of three metabolic alterations was strongly associated with colorectal polyps.

CONCLUSIONS

Abdominal obesity, hypertension, and a high HbA1c% are independently associated with adenomas, whereas a high TG/HDL ratio is associated with serrated polyps. These parameters are easily accessible in clinical practice and may help define high-risk groups for CRC.

Elevated Neutrophil-to-Lymphocyte Ratio in Metabolic Syndrome Is Associated with Increased Risk of Colorectal Adenoma

BACKGROUND

Metabolic syndrome (MetS) is an important cardiovascular risk factor for insulin resistance and has been linked to colorectal adenoma via inflammation. The neutrophil-to-lymphocyte ratio (NLR) has been suggested as an important inflammatory marker. We initiated this investigation to determine the relationship between colorectal adenoma and NLR in patients with MetS.

METHODS

We examined participants who visited the Health Promotion Center at Kosin University Gospel Hospital, Busan, Korea. Subjects who underwent both colonoscopy and liver ultrasonography were included. Colorectal adenoma was defined as the presence of a colon polyp with a histologically adenomatous component. MetS was defined according to the modified National Cholesterol Education Program Adult Treatment Panel III definition for South Asians. Anthropometric measurements and biochemical tests of liver and metabolic function were assessed.

RESULTS

A total of 1007 subjects were included in the study sample. Their mean age was 48.3 ± 9.7 years and 262 (26.0%) subjects had MetS, while 439 (43.6%) subjects had pathologically proven colorectal adenoma. Subjects with MetS were older, more likely to be male, and had significantly higher prevalences of colorectal adenoma (49.2% vs. 41.6%, P = 0.032), nonalcoholic fatty liver disease (62.8% vs. 19.5%, P < 0.001), and higher NLR (2.0 ± 0.9 vs. 1.7 ± 0.7, P < 0.001) compared to those without MetS. High NLR (≥2.0) was an independent factor affecting the prevalence of colorectal adenoma [odds ratio (OR) 1.38, confidence interval (95% CI) 1.02-1.88, P = 0.040], especially in subjects with MetS (OR 1.91, 95% CI 1.12-3.28, P = 0.018).

CONCLUSION

High NLR was associated with increased colorectal adenomatous polyps, particularly in subjects with MetS. Screening colonoscopies for the prevention of colorectal adenoma may be warranted for patients with high NLR and MetS.

Colorectal Cancer Screening in Asia

PURPOSE OF REVIEW

Colorectal cancer (CRC) is increasing in Asia, especially in regions with higher levels of economic development. Several Asian countries have launched population CRC screening programs to combat this devastating disease because previous studies have demonstrated that either fecal occult blood test or lower gastrointestinal endoscopy can effectively reduce CRC mortality.

RECENT FINDINGS

Screening includes engaging the population, testing, administering a confirmation examination, and treating screening-detected neoplasms; thus, monitoring the whole process using measurable indicators over time is of utmost importance. Only when the quality of every step is secured can the effectiveness of CRC screening be maximized. Screening and verification examination rates remain low in Asian countries, and important infrastructure, including cancer or death registry systems, colonoscopy capacity, and reasonable subsidization for screening, is lacking or insufficient. Future research should identify potential local barriers to screening. Good communication and dialog among screening organizers, clinicians, professional societies, and public health workers are indispensible for successful screening programs.

Clinical impact of non-alcoholic fatty liver disease on the occurrence of colorectal neoplasm: Propensity score matching analysis

The effect of non-alcoholic fatty liver disease (NAFLD) on the occurrences of colorectal neoplasm (CRN) at surveillance colonoscopy is rarely evaluated. We retrospectively reviewed medical records of 1,023 patients who had both index and surveillance colonoscopy at a single institution. The cumulative occurrence rates of overall and advanced CRN at the time of surveillance colonoscopy were compared between patients with and without NAFLD using propensity score matching analysis. In an analysis of matched cohort of 441 patients, the cumulative rates of overall CRN occurrence at 3 and 5 years after index colonoscopy were higher in subjects with NAFLD than in those without NAFLD (9.1% vs. 5.0% & 35.2% vs. 25.3%, P = 0.01). Cox regression analysis showed that NAFLD independently increased the risk of overall CRN occurrence with marginal significance (adjusted hazard ratio [aHR]: 1.31 95% CI: 1.01-1.71, P = 0.05). Additionally, NAFLD was associated with the development of 3 or more adenomas at the time of surveillance colonoscopy (aHR: 2.49, 95% CI: 1.20-5.20, P = 0.02). In subgroup analysis based on index colonoscopy risk categories, the effect of NAFLD on the overall CRN occurrence at the time of surveillance colonoscopy was confined to the normal group (aHR: 1.47, 95% CI: 1.05-2.06, P = 0.02). Regarding advanced CRN occurrences at the time of surveillance colonoscopy, age was the only significant risk factor (aHR: 1.06, 95% CI: 1.02-1.10, P = 0.001). NAFLD was associated with overall CRN occurrence, especially in patients with no adenoma at the index colonoscopy. NAFLD may be considered for the determination of the time-interval for surveillance colonoscopy, especially the patients with negative index colonoscopy findings.

Associations among Metabolism, Circadian Rhythm and Age-Associated Diseases

Accumulating epidemiological studies have implicated a strong link between age associated metabolic diseases and cancer, though direct and irrefutable evidence is missing. In this review, we discuss the connection between Warburg effects and tumorigenesis, as well as adaptive responses to environment such as circadian rhythms on molecular pathways involved in metabolism. We also review the central role of the sirtuin family of proteins in physiological modulation of cellular processes and age-associated metabolic diseases. We also provide a macroscopic view of how the circadian rhythm affects metabolism and may be involved in cell metabolism reprogramming and cancer pathogenesis. The aberrations in metabolism and the circadian system may lead to age-associated diseases directly or through intermediates. These intermediates may be either mutated or reprogrammed, thus becoming responsible for chromatin modification and oncogene transcription. Integration of circadian rhythm and metabolic reprogramming in the holistic understanding of metabolic diseases and cancer may provide additional insights into human diseases.

Parameters of Glucose and Lipid Metabolism Affect the Occurrence of Colorectal Adenomas Detected by Surveillance Colonoscopies

PURPOSE

Limited data are available regarding the associations between parameters of glucose and lipid metabolism and the occurrence of metachronous adenomas. We investigated whether these parameters affect the occurrence of adenomas detected on surveillance colonoscopy.

MATERIALS AND METHODS

This longitudinal study was performed on 5289 subjects who underwent follow-up colonoscopy between 2012 and 2013 among 62171 asymptomatic subjects who underwent an initial colonoscopy for a health check-up between 2010 and 2011. The risk of adenoma occurrence was assessed using Cox proportional hazards modeling.

RESULTS

The mean interval between the initial and follow-up colonoscopy was 2.2±0.6 years. The occurrence of adenomas detected by the follow-up colonoscopy increased linearly with the increasing quartiles of fasting glucose, hemoglobin A1c (HbA1c), insulin, homeostasis model assessment of insulin resistance (HOMA-IR), and triglycerides measured at the initial colonoscopy. These associations persisted after adjusting for confounding factors. The adjusted hazard ratios for adenoma occurrence comparing the fourth with the first quartiles of fasting glucose, HbA1c, insulin, HOMA-IR, and triglycerides were 1.50 [95% confidence interval (CI), 1.26-1.77; p(trend)<0.001], 1.22 (95% CI, 1.04-1.43; p(trend)=0.024), 1.22 (95% CI, 1.02-1.46; p(trend)=0.046), 1.36 (95% CI, 1.14-1.63; p(trend)=0.004), and 1.19 (95% CI, 0.99-1.42; p(trend)=0.041), respectively. In addition, increasing quartiles of low-density lipoprotein-cholesterol and apolipoprotein B were associated with an increasing occurrence of adenomas.

CONCLUSION

The levels of parameters of glucose and lipid metabolism were significantly associated with the occurrence of adenomas detected on surveillance colonoscopy. Improving the parameters of glucose and lipid metabolism through lifestyle changes or medications may be helpful in preventing metachronous adenomas.

Case-control study of metabolic syndrome and ovarian cancer in Chinese population

Background

Recent studies have proved metabolic syndrome (MetS) was linked to cancer risks. However, few data has examined the relationship between MetS and epithelial ovarian cancer (EOC).

Methods

We conducted a population-based case-control study in Tianjin Medical University Cancer Institute and Hospital, China (2010–2015) that enrolled 573 EOC patients and 1146 matched controls. Data were collected through in-person interviews, anthropometric measurement, and 8-h fasting bloods drawn. MetS was estimated by Chinese Diabetes Society (CDS) definition requiring presence of ≥3 of the following risk factors: 1) body mass index (BMI) ≥25.0 kg/m²,2) fasting plasma glucose ≥6.1 mmol/L or 2-h plasma glucose ≥ 7.8 mmol/L, 3) systolic blood pressure ≥140 mmHg or diastolic blood pressure ≥90 mmHg, 4) triglyceride (TG) ≥1.70 mmol/L or high-density lipoprotein cholesterol (HDL-C) < 1.0 mmol/L. Statistics were completed using chi-square tests and logistic regression analysis. The survival analysis was conducted by the Kaplan-Meier method and Cox proportional hazard regression models.

Results

MetS was significantly more prevalent among EOC (25.13%) than controls (6.89%). A statistically significant increase risk for EOC was observed for MetS (multivariable-adjusted OR = 3.187; 95% CI: 2.135–4.756). MetS was significantly associated with histological grade (P < 0.001), FIGO stage (P = 0.003), and lymph node (LN) status (P = 0.002) of EOC. In binary logistic regression analysis, the presence of MetS predicts the risk of advanced FIGO stage (OR = 2.155, 95% CI: 1.327–3.498, P = 0.002), lower differentiation (OR = 2.472, 95% CI: 1.164–5.250, P = 0.019), and LN metastasis (OR = 2.590, 95% CI: 1.089–6.160, P = 0.031) of EOC. Moreover, MetS is the independent factor for the evaluation of PFS and OS of EOC patients (both of them P < 0.001) in Cox proportional hazard model.

Conclusion

MetS is obviously related to increased EOC risk. EOC patients with MetS in Chinese population were found to have statistically significant tumor advanced stage, low differentiation, LN metastasis and poor prognosis.

Bariatric Surgery Prior to Index Screening Colonoscopy Is Associated With a Decreased Rate of Colorectal Adenomas in Obese Individuals

Objectives:

Obesity is an important risk factor for the development of colorectal cancer (CRC). Although the impact of bariatric surgery on CRC is conflicting, its impact on precursor lesions is unknown. The aim of this study was to determine whether bariatric surgery before index screening colonoscopy is associated with decreased development of colorectal adenomas.

Methods:

We performed a retrospective cohort study of bariatric surgery patients who had undergone index, screening colonoscopy at an academic center from 2001 to 2014. Patients who had bariatric surgery at least 1 year before index colonoscopy were compared with those who had surgery after colonoscopy, using multivariable logistic regression to control for presurgical body mass index, sex, gender, race, type of surgery, aspirin use, metformin use, smoking, and age at colonoscopy.

Results:

One hundred and twenty-five obese individuals who had bariatric surgery before colonoscopy were compared with 223 individuals who had colonoscopy after surgery. Adenomatous polyps were found in 16.8% of individuals who had surgery first vs. 35.5% who had colonoscopy before bariatric surgery (unadjusted odds ratio (OR) 0.37, 95% confidence interval (CI): 0.21–0.64, P=0.0003). After multivariable adjustment, bariatric surgery before index screening colonoscopy was associated with a decreased risk of adenomas at index colonoscopy (adjusted OR 0.37, 95% CI: 0.19–0.69, P=0.002).

Conclusions:

Bariatric surgery is associated with a decreased risk of colorectal adenomas in obese individuals without a family history of CRC.

Faecal haemoglobin concentration influences risk prediction of interval cancers resulting from inadequate colonoscopy quality: analysis of the Taiwanese Nationwide Colorectal Cancer Screening Program

OBJECTIVES

Interval colorectal cancer (CRC) after colonoscopy may affect effectiveness and cost-effectiveness of screening programmes. We aimed to investigate whether and how faecal haemoglobin concentration (FHbC) of faecal immunochemical testing (FIT) affected the risk prediction of interval cancer (IC) caused by inadequate colonoscopy quality in a FIT-based population screening programme.

DESIGN

From 2004 to 2009, 29 969 subjects underwent complete colonoscopy after positive FIT in the Taiwanese Nationwide CRC Screening Program. The IC rate was traced until the end of 2012. The incidence of IC was calculated in relation to patient characteristics, endoscopy-related factors (such adenoma detection rate (ADR)) and FHbC. Poisson regression analysis was performed to assess the potential risk factors for colonoscopy IC.

RESULTS

One hundred and sixty-two ICs developed after an index colonoscopy and the estimated incidence was 1.14 per 1000 person-years of observation for the entire cohort. Increased risk of IC was most remarkable in the uptake of colonoscopy in settings with ADR lower than 15% (adjusted relative risk (aRR)=3.09, 95% CI 1.55 to 6.18) and then higher FHbC (μg Hb/g faeces) (100-149: aRR=2.55, 95% CI 1.52 to 4.29, ≥150: aRR=2.74, 95% CI 1.84 to 4.09) with adjustment for older age and colorectal neoplasm detected at baseline colonoscopy. Similar findings were observed for subjects with negative index colonoscopy.

CONCLUSIONS

Colonoscopy ICs arising from FIT-based population screening programmes were mainly influenced by inadequate colonoscopy quality and independently predicted by FHbC that is associated with a priori chance of advanced neoplasm. This finding is helpful for future modification of screening logistics based on FHbC.

Metabolic syndrome is a risk factor for adenoma occurrence at surveillance colonoscopy: A single-center experience in Korea

We investigated the risk factors for adenoma occurrence at surveillance colonoscopy, especially focusing on patient characteristics, including metabolic factors.Surveillance colonoscopy intervals depend on baseline adenoma characteristics. However, patients' characteristics may also influence the occurrence of adenomas.Of 62,171 asymptomatic subjects who underwent colonoscopy for a health check-up between 2010 and 2011, 4869 subjects who underwent follow-up colonoscopy between 2012 and 2013 were included in this longitudinal study. The risk of adenoma occurrence was assessed using Cox proportional hazards modeling.Of 4869 subjects, 2827 (58.1%), 1619 (33.3%), and 423 (8.7%) were assigned to the normal, low-risk, and high-risk groups, respectively, according to baseline adenoma characteristics. The mean interval between initial and follow-up colonoscopy was 2.2 ± 0.6 years. Certain patient factors, including older age (≥50 years; adjusted hazard ratio [aHR], 2.08; 95% CI, 1.73-2.49), male sex (aHR, 1.69; 95% CI, 1.30-2.19), metabolic syndrome (MetS) (aHR, 1.28; 95% CI, 1.09-1.51), obesity (aHR, 1.17; 95% CI, 1.02-1.34), elevated fasting blood glucose levels (aHR, 1.37; 95% CI, 1.19-1.58), and elevated triglyceride levels (aHR, 1.19; 95% CI, 1.03-1.37), as well as baseline adenoma characteristics, were associated with a higher risk of adenoma occurrence at follow-up colonoscopy. The cumulative incidence of adenoma occurrence in the high-risk group was higher than that in the low-risk group, whereas the incidence in the high-risk group without MetS was comparable with that in the low-risk group with MetS.Patient characteristics, such as MetS, obesity, older age, and male sex, in addition to adenoma characteristics, were independent risk factors for adenoma occurrence at surveillance colonoscopy. These patient characteristics may be considered in surveillance colonoscopy intervals.

Metabolic factors affect the occurrence of colorectal neoplasm on surveillance colonoscopies

BACKGROUND AND AIM

Although metabolic factors such as obesity and hyperlipidemia were reported to be associated with high prevalence of colorectal neoplasm (CRN), their influence on the occurrence of CRN at surveillance colonoscopy has not been clarified. The purpose of this study was to analyze the association between metabolic factors and the risk of CRN at the time of surveillance colonoscopy.

METHODS

We reviewed the medical records of 1792 asymptomatic subjects (average 52.1 years, 1233 male) who underwent screening and follow-up surveillance colonoscopies. Fasting glucose level, fasting insulin level, hemoglobin A1c (HbA1c), lipid profile, high sensitivity C-reactive protein, and colonoscopic findings at the time of baseline screening were analyzed to find any associations with the occurrence of CRN at the time of surveillance colonoscopy.

RESULTS

The median interval between screening and surveillance colonoscopies was 3.34 years. The 3- and 5-year cumulative CRN incidences were 22.3% and 54.8%, respectively. Several metabolic factors such as hypertension, waist circumference, fasting insulin, fasting glucose, HbA1c, and triglyceride were associated with the occurrence of CRN in univariate analysis. Age, current alcohol drinker status, and high-risk colonoscopy findings at baseline remained independent risk factors for CRN occurrence in multivariate analysis. High waist circumference was also an independent risk factor (hazard ratio 1.03, 95% CI 1.02-1.04; P < 0.001).

CONCLUSIONS

Metabolic factors, especially waist circumference, affect CRN occurrence at the time of surveillance colonoscopy. The surveillance colonoscopy interval may be optimized based on metabolic factors and screening colonoscopy findings.

Fecal hemoglobin concentration is useful for risk stratification of advanced colorectal neoplasia

BACKGROUND

Although a fecal immunochemical test (FIT) allows quantitation of fecal hemoglobin (f-Hb), it is typically used as a binary result to identify subjects above a predetermined cut-off concentration.

AIMS

To investigate whether f-Hb concentration is useful for risk stratification of advanced colorectal neoplasia (CRN).

METHODS

This was a retrospective study conducted in a university hospital in Korea. Of 34,547 participants who underwent FIT from June 2013 to May 2015, 1532 (4.4%) showed positive results (≥100ng Hb/ml). Of participants with positive results, 738 subjects aged ≥50 years who underwent colonoscopy were analyzed.

RESULTS

Increasing quartile of f-Hb concentration (Q4 vs. Q1; odds ratio, 3.87; 95% confidence interval, 2.36-6.34), as well as older age, male sex, smoking, and metabolic syndrome (MetS), was significantly associated with a higher prevalence of advanced CRN. Risk for advanced CRN increased 5.13-, 4.27-, 5.12-, and 7.15-fold, respectively, among individuals with f-Hb in the fourth quartile who had risk factors such as age ≥70 years, male sex, smoking, and MetS compared with individuals with first quartile levels of f-Hb who did not have those risk factors.

CONCLUSION

In addition to age, sex, smoking status, and MetS, f-Hb concentration in individuals with positive results from FIT can be used to stratify the probability of detection of advanced CRN.

Optimizing post-polypectomy surveillance: A practical guide for the endoscopist

Several gastrointestinal societies strongly recommend colonoscopy surveillance after endoscopic and surgical resection of colorectal neoplasms. Common denominators to these recommendations include: high-quality baseline colonoscopy before inclusion in a surveillance program; risk stratification based on clinicopathological profiles to guide surveillance intervals; and endoscopist responsibility for providing surveillance advice. Considerable variability also exists between guidelines (i.e. regarding risk classification and surveillance intervals). In this review, we examine key factors for quality of post-polypectomy surveillance practice, in particular bowel preparation, endoscopic findings at baseline examination and adherence to surveillance recommendations. Frequently asked questions by the practising endoscopist are addressed.