Optimization of colonoscopy quality: Comprehensive review of the literature and future perspectives

Colonoscopy is crucial in preventing colorectal cancer (CRC) and reducing associated mortality. This comprehensive review examines the importance of high-quality colonoscopy and associated quality indicators, including bowel preparation, cecal intubation rate, withdrawal time, adenoma detection rate (ADR), complete resection, specimen retrieval, complication rates, and patient satisfaction, while also discussing other ADR-related metrics. Additionally, the review draws attention to often overlooked quality aspects, such as nonpolypoid lesion detection, as well as insertion and withdrawal skills. Moreover, it explores the potential of artificial intelligence in enhancing colonoscopy quality and highlights specific considerations for organized screening programs. The review also emphasizes the implications of organized screening programs and the need for continuous quality improvement. A high-quality colonoscopy is crucial for preventing postcolonoscopy CRC- and CRC-related deaths. Health-care professionals must develop a thorough understanding of colonoscopy quality components, including technical quality, patient safety, and patient experience. By prioritizing ongoing evaluation and refinement of these quality indicators, health-care providers can contribute to improved patient outcomes and develop more effective CRC screening programs.

Double-contrast barium enema is no longer justified as a backup examination for colonoscopy in the population screening program: Population study in an organized fecal immunochemical test-based screening program

BACKGROUND AND AIM

Currently, some countries still acknowledge double-contrast barium enema (DCBE) as a backup confirmatory examination when colonoscopy is not feasible or incomplete in colorectal cancer (CRC) screening programs. This study aims to compare the performance of colonoscopy and DCBE in terms of the risk of incident CRC after negative results in the fecal immunochemical test (FIT)-based Taiwan Colorectal Cancer Screening Program.

METHODS

Subjects who had positive FITs and received confirmatory exams, either colonoscopy or DCBE, without the findings of neoplastic lesions from 2004 to 2013 in the screening program comprised the study cohort. Both the colonoscopy and DCBE subcohorts were followed until the end of 2018 and linked to the Taiwan Cancer Registry to identify incident CRC cases. Multivariate analysis was conducted to compare the risk of incident CRC in both subcohorts after controlling for potential confounders.

RESULTS

A total of 102 761 colonoscopies and 5885 DCBEs were performed after positive FITs without neoplastic findings during the study period. By the end of 2018, 2113 CRCs (2.7 per 1000 person-years) and 368 CRCs (7.6 per 1000 person-years) occurred in the colonoscopy and DCBE subcohorts, respectively. After adjusting for major confounders, DCBE had a significantly higher risk of incident CRC than colonoscopy, with an adjusted HR of 2.81 (95% CI = 2.51-3.14).

CONCLUSIONS

In the FIT screening program, using DCBE as a backup examination was associated with a nearly threefold risk of incident CRC compared with colonoscopy, demonstrating that it is no longer justified as a backup examination for incomplete colonoscopy.

Cold Versus Hot Snare Polypectomy for Small Colorectal Polyps : A Pragmatic Randomized Controlled Trial

BACKGROUND

Although cold snare polypectomy (CSP) is considered effective in reducing delayed postpolypectomy bleeding risk, direct evidence supporting its safety in the general population remains lacking.

OBJECTIVE

To clarify whether CSP would reduce delayed bleeding risk after polypectomy compared with hot snare polypectomy (HSP) in the general population.

DESIGN

Multicenter randomized controlled study. (ClinicalTrials.gov: NCT03373136).

SETTING

6 sites in Taiwan, July 2018 through July 2020.

PARTICIPANTS

Participants aged 40 years or older with polyps of 4 to 10 mm.

INTERVENTION

CSP or HSP to remove polyps of 4 to 10 mm.

MEASUREMENTS

The primary outcome was the delayed bleeding rate within 14 days after polypectomy. Severe bleeding was defined as a decrease in hemoglobin concentration of 20 g/L or more, requiring transfusion or hemostasis. Secondary outcomes included mean polypectomy time, successful tissue retrieval, en bloc resection, complete histologic resection, and emergency service visits.

RESULTS

A total of 4270 participants were randomly assigned (2137 to CSP and 2133 to HSP). Eight patients (0.4%) in the CSP group and 31 (1.5%) in the HSP group had delayed bleeding (risk difference, -1.1% [95% CI, -1.7% to -0.5%]). Severe delayed bleeding was also lower in the CSP group (1 [0.05%] vs. 8 [0.4%] events; risk difference, -0.3% [CI, -0.6% to -0.05%]). Mean polypectomy time (119.0 vs. 162.9 seconds; difference in mean, -44.0 seconds [CI, -53.1 to -34.9 seconds]) was shorter in the CSP group, although successful tissue retrieval, en bloc resection, and complete histologic resection did not differ. The CSP group had fewer emergency service visits than the HSP group (4 [0.2%] vs. 13 [0.6%] visits; risk difference, -0.4% [CI, -0.8% to -0.04%]).

LIMITATION

An open-label, single-blind trial.

CONCLUSION

Compared with HSP, CSP for small colorectal polyps significantly reduces the risk for delayed postpolypectomy bleeding, including severe events.

PRIMARY FUNDING SOURCE

Boston Scientific Corporation.

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.

Risk of colonoscopy-related complications in a fecal immunochemical test-based population colorectal cancer screening program

BACKGROUND

The likelihood of advanced or synchronous neoplasms is significantly higher in fecal immunochemical test (FIT)-positive individuals than in the general population. The magnitude of the colonoscopy-related complication rate in FIT-positive individuals remains unknown. This study aimed to elucidate the colonoscopy-related complication rate after a positive FIT result and compare it with the rate when colonoscopy was performed for other purposes.

METHODS

Information regarding colonoscopy-related severe complications after a positive FIT result (FIT-colonoscopy) and ordinary colonoscopy during 2010-2014 was collected from the Taiwanese Colorectal Cancer Screening Program Database and National Health Insurance Research Database. Severe complications included significant bleeding, perforation, and cardiopulmonary events ≤ 14 days after colonoscopy. The number of events per 1000 procedures was used to quantify complication rates. Multivariate analysis was conducted to assess the association of various factors with severe complications associated with FIT-colonoscopy compared with ordinary colonoscopy.

RESULTS

319 114 FIT-colonoscopies (214 955 patients) were identified, 51 242 (16.1 %) of which included biopsy and 94 172 (29.5 %) included polypectomy. Overall, 2125 significant bleedings (6.7 ‰) and 277 perforations (0.9 ‰) occurred ≤ 14 days after FIT-colonoscopy. Polypectomy, antiplatelet use, and anticoagulant use were associated with higher risk of complications (adjusted odds ratio [aOR] 4.41, 95 % confidence interval [CI] 4.05-4.81); aOR 1.35, 95 %CI 1.12-1.53; aOR 1.88, 95 %CI 0.61-5.84, respectively). Compared with ordinary colonoscopy, FIT-colonoscopy involved significantly higher risk of significant bleeding (aOR 3.10, 95 %CI 2.90-3.32).

CONCLUSIONS

FIT-colonoscopy was associated with a more than two-fold risk of significant bleeding, especially when polypectomy was performed.

Long-term effectiveness of faecal immunochemical test screening for proximal and distal colorectal cancers

OBJECTIVE

To measure the effects of faecal immunochemical test (FIT) for colorectal cancer (CRC) screening on overall and site-specific long-term effectiveness of population-based organised service screening.

DESIGN

A prospective cohort study of Taiwanese nationwide biennial FIT screening was performed. A total of 5 417 699 eligible subjects were invited to attend screening from 2004 through 2009 and were followed up until 2014. We estimated the adjusted relative rates (aRRs) on the effectiveness of reducing advanced-stage CRC (stage II+) and CRC death by Bayesian Poisson regression models with the full adjustment for a cascade of self-selection factors (including the screening rate and the colonoscopy rate) and the completeness of colonoscopy together with demographic features.

RESULTS

FIT screening (exposed vs unexposed) reduced the incidence of advanced-stage CRC (48.4 vs 75.7 per 100 000) and mortality (20.3 vs 41.3 per 100 000). Statistically significant reductions of both incidence of advanced-stage CRCs (aRR=0.66, 95% CI 0.63 to 0.70) and deaths from CRC (aRR=0.60, 95% CI 0.57 to 0.64) were noted. FIT screening was more effective in reducing distal advanced-stage CRCs (aRR=0.61, 95% CI 0.58 to 0.64) and CRC mortality (aRR=0.56, 95% CI 0.53 to 0.69) than proximal advanced CRCs (aRR=0.84, 95% CI 0.77 to 0.92) and CRC mortality (aRR=0.72, 95% CI 0.66 to 0.80).

CONCLUSION

A large-scale population-based biennial FIT screening demonstrates 34% significant reduction of advanced-stage CRCs and 40% reduction of death from CRC with larger long-term effectiveness in the distal colon than the proximal colon. Our findings provide a strong and consistent evidence-based policy for supporting a sustainable population-based FIT organised service screening worldwide. The disparity of site-specific long-term effectiveness also provides an insight into the remedy for lower effectiveness of FIT screening in the proximal colon.

Faecal immunochemical test after negative colonoscopy may reduce the risk of incident colorectal cancer in a population-based screening programme

OBJECTIVE

Subjects with a positive faecal immunochemical test (FIT) have a much higher likelihood of advanced neoplasms than the general population. Whether FIT-positive subjects with negative colonoscopy should receive subsequent FIT screening remain unclear.

DESIGN

Subjects with a negative colonoscopy after positive FIT in the first screening in the Taiwanese Colorectal Cancer (CRC) Screening Program 2004-2009 were followed until the end of 2014. CRC incidence was compared between those who did and did not receive subsequent FIT screening. Cox regression analysis was conducted, adjusting for major confounders to investigate whether subsequent FIT was associated with lower risk of incident CRC.

RESULTS

The study cohort was comprised of 9179 subjects who had negative diagnostic colonoscopy after positive FIT in 2004-2009, of whom 6195 received subsequent FIT during the study period. The CRC incidence (per 1000 person years) was 1.34 in those who received subsequent FIT and 2.69 in those who did not, with corresponding adjusted HR (aHR) of 0.47 (95% CI 0.31 to 0.71). Lower adenoma detection rate of diagnostic colonoscopy was associated with higher risk of incident CRC but became non-significant in multivariable analysis after adjustment for subsequent FIT. Higher baseline faecal haemoglobin concentration (FHbC, μg haemoglobin/g faeces) was associated with increased risk of incident CRC (reference: FHbC=20-39; aHR=1.93 (1.04-3.56), 0.95 (0.45-2.00), 2.26 (1.16-4.43) and 2.44 (1.44-4.12) for FHbC=40-59, 60-99, 100-149 and ≥150, respectively).

CONCLUSION

Subsequent FIT should be scheduled after negative colonoscopy to detect missed neoplasms and reduce the risk of incident CRC in a national FIT screening programme.

Classifying interval cancers as false negatives or newly occurring in fecal immunochemical testing

OBJECTIVE

To classify interval colorectal cancers as false negatives or newly occurring cases in a biennial Fecal immunochemical test (FIT) screening program and by various interscreening intervals.

SETTING

Data from the Taiwanese biennial colorectal cancer screening program involving FIT from 2004 to 2014 were used to estimate the incidence rate of asymptomatic colorectal cancer and the rate of its subsequent progression to clinical mode.

METHODS

The sensitivity of detecting asymptomatic colorectal cancers excluding newly developed colorectal cancers was compared to the conventional estimate of sensitivity, the complementary FIT interval cancer rate as a percentage of the expected incidence rate ((1-I/E)%). The relative contribution of newly developed or false-negative cases to FIT interval colorectal cancers was estimated by age and interscreening intervals.

RESULTS

The Taiwanese biennial fecal immunochemical test screening program had a conventional sensitivity estimate of 70.2%. After newly developed colorectal cancers were separated from FIT interval cancers, the ability to detect asymptomatic colorectal cancers increased to 75.5%. FIT interval colorectal cancers from the biennial program mainly resulted from newly developed colorectal cancers (68.8%). The corresponding figures decreased to 61.1% for the annual program but increased to 74.7% for the triennial program. The preponderance of newly developed colorectal cancers among FIT interval cancers was more prominent in screenees aged 50-59  than in those aged 60-69.

CONCLUSIONS

Newly developed colorectal cancers showed a predominance among the FIT interval colorectal cancers in particular in the younger population screened. It is desirable to identify high-risk individuals to offer them a short interscreening interval or advanced detection methods to reduce their odds of developing interval cancer.

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.

Comparison of the effect of clarithromycin triple therapy with or without N-acetylcysteine in the eradication of Helicobacter pylori: a randomized controlled trial

BACKGROUND

Whether adjunctive N-acetylcysteine (NAC) may improve the efficacy of triple therapy in the first-line treatment of Helicobacter pylori infection remains unknown. Our aim was to compare the efficacy of 14-day triple therapy with or without NAC for the first-line treatment of H. pylori.

MATERIAL AND METHODS

Between 1 January 2014 and 30 June 2018, 680 patients with H. pylori infection naïve to treatment were enrolled in this multicenter, open-label, randomized trial. Patients were randomly assigned to receive triple therapy with NAC [NAC-T14, dexlansoprazole 60 mg four times daily (q.d.); amoxicillin 1 g twice daily (b.i.d.), clarithromycin 500 mg b.i.d., NAC 600 mg b.i.d.] for 14 days, or triple therapy alone (T14, dexlansoprazole 60 mg q.d.; amoxicillin 1 g b.i.d., clarithromycin 500 mg b.i.d.) for 14 days. Our primary outcome was the eradication rates by intention to treat (ITT). Antibiotic resistance and CYP2C19 gene polymorphism were determined.

RESULTS

The ITT analysis demonstrated H. pylori eradication rates in NAC-T14 and T14 were 81.7% [276/338, 95% confidence interval (CI): 77.5-85.8%] and 84.3% (285/338, 95% CI 80.4-88.2%), respectively. In 646 participants who adhered to their assigned therapy, the eradication rates were 85.7% and 88.0% with NAC-T14 and T14 therapies, respectively. There were no differences in compliance or adverse effects. The eradication rates in subjects with clarithromycin-resistant, amoxicillin-resistant, or either clarithromycin/amoxicillin resistant strains were 45.2%, 57.9%, and 52.2%, respectively, for NAC-T14, and were 66.7%, 76.9%, and 70.0%, respectively, for T14. The efficacy of NAC-T14 and T14 was not affected by CYP2C19 polymorphism.

CONCLUSION

Add-on NAC to triple therapy was not superior to triple therapy alone for first-line H. pylori eradication [ClinicalTrials.gov identifier: NCT02249546].

Long-term changes of gut microbiota, antibiotic resistance, and metabolic parameters after Helicobacter pylori eradication: a multicentre, open-label, randomised trial

BACKGROUND

In first-line treatment of Helicobacter pylori, we have previously shown that the eradication frequency was 83·7% (95% CI 80·4-86·6) for triple therapy for 14 days (T14; lansoprazole 30 mg, amoxicillin 1 g, and clarithromycin 500 mg, all given twice daily), 85·9% (82·7-88·6) for concomitant therapy for 10 days (C10; lansoprazole 30 mg, amoxicillin 1 g, clarithromycin 500 mg, and metronidazole 500 mg, all given twice daily), and 90·4% (87·6-92·6) for bismuth quadruple therapy for 10 days (BQ10; bismuth tripotassium dicitrate 300 mg four times a day, lansoprazole 30 mg twice daily, tetracycline 500 mg four times a day, and metronidazole 500 mg three times a day). In this follow-up study, we assess short-term and long-term effects of these therapies on the gut microbiota, antibiotic resistance, and metabolic parameters.

METHODS

This was a multicentre, open-label, randomised trial done at nine medical centres in Taiwan. Adult patients (>20 years) with documented H pylori infection were randomly assigned (1:1:1, with block sizes of six) to receive T14, C10, or BQ10. We assessed long-term outcomes (reinfection frequency, changes in the gut microbiota, antibiotic resistance, and metabolic parameters) in patients with available data, excluding all protocol violators and those with unknown post-treatment H pylori status. Faecal samples were collected before treatment and 2 weeks, 2 months, and at least 1 year after eradication therapy. Amplification of the V3 and V4 hypervariable regions of the 16S rRNA was done followed by high-throughput sequencing. Susceptibility testing for faecal Escherichia coli and Klebsiella pneumoniae was done. This trial is complete and registered with ClinicalTrials.gov, NCT01906879.

FINDINGS

Between July 17, 2013, and April 20, 2016, 1620 participants were randomly assigned to the three treatment groups (540 [33%] per group). 1214 (75%) attended 1-year follow-up and are included in this analysis. Compared with baseline, alpha diversity was significantly reduced 2 weeks after T14 (p=0·0002), C10 (p<0·0001), and BQ10 (p<0·0001) treatment. Beta diversity was also significantly altered 2 weeks after T14 (p=0·0010), C10 (p=0·0001), and BQ10 (p=0·0001). Alpha diversity and beta diversity were restored at week 8 (p=0·14 and p=0·918, respectively) and 1 year (p=0·14 and p=0·918) after T14, but were not fully recovered at week 8 and after 1 year in patients treated with C10 (p=0·0001 and p=0·013 at week 8; p=0·019 and p=0·064 at 1 year) and BQ10 (p<0·0001 and p=0·0002; p=0·001 and p=0·029). A transient increase at week 2 after T14 and C10 of the resistance rates of E coli to ampicillin-sulbactam (12% [15/127] to 66% [38/58] for T14, 7% [10/135] to 64% [28/44] for C10), cefazolin (13% [16/127] to 43% [25/58] for T14, 10% [13/135] to 41% [18/44] for C10), cefmetazole (8% [10/127] to 26% [15/58] for T14, 4% [5/135] to 18% [8/44] for C10), levofloxacin (8% [10/127] to 35% [20/58] for T14, 7% [10/135] to 32% [14/44] for C10), gentamicin (13% [19/146] to 47% [27/58] for T14, 15% [22/149] to 45% [20/44] for C10), and trimethoprim-sulfamethoxazole (33% [48/146] to 86% [50/58] for T14, 28% [42/148] to 86% [38/44] for C10; p<0·05 in paired samples in the above analyses) returned to basal state at week 8 and after 1 year. Although bodyweight and body-mass index slightly increased, there were significant improvements in metabolic parameters, with a decrease in insulin resistance, triglycerides, and LDL and an increase in HDL. Overall, there was no significant change in the prevalence of metabolic syndrome at week 8 and 1 year after T14, C10, and BQ10.

INTERPRETATION

Eradication of H pylori infection has minimal disruption of the microbiota, no effect on antibiotic resistance of E coli, and some positive effects on metabolic parameters. Collectively, these results lend support to the long-term safety of H pylori eradication therapy.

FUNDING

National Taiwan University Hospital and Ministry of Science and Technology of Taiwan.

Effects of screening and universal healthcare on long-term colorectal cancer mortality

BACKGROUND

To evaluate the time trends of colorectal cancer (CRC) affected by a Nationwide Colorectal Cancer Screening (NCCS) programme with biennial faecal immunochemical testing (FIT) and Nationwide Healthcare Insurance (NHI).

METHODS

Data from the national registries on cancer and death in Taiwan were separated into years 1984-1993, 1994-2003 and 2004-2013 based on the implementations of NHI (starting 1995) and NCCS (starting 2004). The adult population was divided into three age groups (young, 30-49; middle-aged, 50-69; and old, 70-84 years); only the middle-aged were eligible for NCCS. Crude and adjusted effects of NCCS and NHI were quantified by percentage change and 95% confidence interval (CI) with respect to CRC mortality, according to the attributions from incidence and survival.

RESULTS

Within 335 million person-years of follow-up, 204 362 incident CRCs and 80 771 CRC-related deaths were identified. Increasing mortality trends were noted for 1994-2003 (post-NHI) vs 1984-1993 due to remarkable increasing incidence trends that could not be offset by improved survival as a result of NHI. During 2004-13 (post-NCCS), mortality continued to increase by 15% (95% CI: 10-21%) in young adults (30-49 years) and 8% (95% CI: 6-11%) in older adults (70-84 years), whereas middle-aged adults (50-69 years) had a reduction of 7% (95% CI: 5-9%) due to a remarkable stage shift and subsequent improvement in survival. In the middle-aged adults, increased incidence was less but survival improvement was more compared with other age groups.

CONCLUSIONS

Whereas universal healthcare insurance led to improvement in CRC survival, FIT-based screening has made an even greater contribution to reducing CRC mortality.

Sampling-based Markov regression model for multistate disease progression: Applications to population-based cancer screening program

To develop personalized screening and surveillance strategies, the information required to superimpose state-specific covariates into the multi-step progression of disease natural history often relies on the entire population-based screening data, which are costly and infeasible particularly when a new biomarker is proposed. Following Prentice's case-cohort concept, a non-standard case-cohort design from a previous study has been adapted for constructing multistate disease natural history with two-stage sampling. Nonetheless, the use of data only from first screens may invoke length-bias and fail to consider the test sensitivity. Therefore, a new sampling-based Markov regression model and its variants are proposed to accommodate additional subsequent follow-up data on various detection modes to construct state-specific covariate-based multistate disease natural history with accuracy and efficiency. Computer simulation algorithms for determining the required sample size and the sampling fraction of each detection mode were developed either through power function or the capacity of screening program. The former is illustrated with breast cancer screening data from which the effect size and the required sample size regarding the effect of BRCA on multistate outcome of breast cancer were estimated. The latter is applied to population-based colorectal cancer screening data to identify the optimal sampling fraction of each detection mode.

The Rise of Colorectal Cancer in Asia: Epidemiology, Screening, and Management

PURPOSE OF REVIEW

Colorectal cancer (CRC) remains the third most commonly diagnosed cancer globally, and its incidence and mortality rates have been on the rise in Asia. In this paper, we summarize the recent trends and screening challenges of CRC in this region.

RECENT FINDINGS

In 2018, Asia had the highest proportions of both incident (51.8%) and mortality (52.4%) CRC cases (all genders and ages) per 100,000 population in the world. In addition, there has been a rising trend of this disease across Asia with some regional geographic variations. This rise in CRC can be attributed to westernized dietary lifestyle, increasing population aging, smoking, physical inactivity, and other risk factors. In curbing the rising trend, Japan, South Korea, Singapore, and Taiwan have launched nationwide population-based screening programs. CRC screening across this region has been found to be effective and cost-effective compared with no screening at all. The emergence of new therapies has caused a reduction in case fatality; however, these new options have had a limited impact on cure rates and long-term survival due to the great disparity in treatment capacity/resources and screening infrastructures among Asian countries with different degrees of economic development. CRC is still rising in Asia, and implementation of screening is necessary for moderate- to high-incidence countries and construction of treatment capacity is the priority task in low-incidence and low-income countries. Unless countries in Asia implement CRC screening, the incidence and mortality rates of this disease will continue to rise especially with the rapidly rising population growth, economic development, westernized lifestyle, and increasing aging.

Time to Colonoscopy and Risk of Colorectal Cancer in Patients With Positive Results From Fecal Immunochemical Tests

BACKGROUND & AIMS

In patients with positive results from a fecal immunochemical test (FIT), failure to receive a timely follow-up colonoscopy may be associated with higher risks of colorectal cancer (CRC) and advanced-stage CRC. We evaluated the prevalence of any CRC and advanced-stage CRC associated with delays in follow-up colonoscopies for patients with positive results from a FIT.

METHODS

We collected data from 39,346 patients (age, 50-69 years) who participated in the Taiwanese Nationwide Screening Program from 2004 through 2012 and had completed a colonoscopy more than 1 month after a positive result from a FIT. Risks of any CRC and advanced-stage CRC (stage III-IV) were evaluated using logistic regression models and results expressed as adjusted odds ratios (aORs) and corresponding 95% CIs.

RESULTS

In our cohort, 2003 patients received a diagnosis of any CRC and 445 patients were found to have advanced-stage disease. Compared with colonoscopy within 1-3 months (cases per 1000 patients: 50 for any CRC and 11 for advanced-stage disease), risks were significantly higher when colonoscopy was delayed by more than 6 months for any CRC (aOR, 1.31; 95% CI, 1.04-1.64; 68 cases per 1000 patients) and advanced-stage disease (aOR, 2.09; 95% CI, 1.43-3.06; 24 cases per 1000 patients). The risks continuously increased when colonoscopy was delayed by more than 12 months for any CRC (aOR, 2.17; 95% CI, 1.44-3.26; 98 cases per 1000 patients) and advanced-stage disease (aOR, 2.84; 95% CI, 1.43-5.64; 31 cases per 1000 patients). There were no significant differences for colonoscopy follow up at 3-6 months for risk of any CRC (aOR, 0.98; 95% CI, 0.86-1.12; 49 cases per 1000 patients) or advanced-stage disease (aOR, 0.95; 95% CI, 0.72-1.25; 10 cases per 1000 patients).

CONCLUSIONS

In an analysis of data from the Taiwanese Nationwide Screening Program, we found that among patients with positive results from a FIT, risks of CRC and advanced-stage disease increase with time. These findings indicate the importance of timely colonoscopy after a positive result from a FIT.

Risk of delayed bleeding before and after implementation of cold snare polypectomy in a screening colonoscopy setting

Background and study aims  Cold snare polypectomy (CSP) is considered to be effective in reducing risk of delayed bleeding but randomized trials fail to support this owing to the small sample size. The current study aimed to compare risk of delayed bleeding before and after implementation of CSP in a screening colonoscopy setting. Patients and methods  This study retrospectively analyzed a prospectively maintained screening colonoscopy database in a university hospital in Taiwan. We compared the rate of delayed bleeding before and after implementation within similar periods (18 months and 15 months) and the respective number of polypectomies (1,304 and 1,255) performed to remove small and diminutive polyps. The main outcome measurement was delayed bleeding within the two periods. Multivariate analysis was performed to adjust for major confounders. Results  A total of 1,304 and 1,225 subjects received hot snare polypectomy (HSP) and CSP in two separate periods, respectively. Compared with the HSP, the CSP had a lower rate of delayed bleeding (0.1 % vs . 1.1 %, P  < 0.001), severe bleeding (0 % vs. 0.7 %, P  < 0.01), need for second-look colonoscopy (0 % vs. 0.8 %, P  < 0.01), and emergency service visits (0.1 % vs . 1.0 %, P  < 0.01). Total procedure time (12.60 ± 11.45 vs . 16.48 ± 14.27 min/person, P  < 0.01) and duration of hospital stay (1.18 ± 0.50 vs . 1.53 ± 5.78 hour/person, P  < 0.03) were also shorter after CSP implementation. Multivariate analysis showed that HSP was an independent risk factor for delayed bleeding after adjusting for age, gender, and number of polyps (adjusted odds ratio 14.4;95 % confidence interval = 1.88 - 110.6). Conclusion  Implementation of CSP significantly reduces risk of delayed bleeding associated with removing small and diminutive polyps in screening colonoscopy.

Efficacies of Genotypic Resistance-Guided vs Empirical Therapy for Refractory Helicobacter pylori Infection

BACKGROUND & AIMS

We aimed to compare the efficacy of genotypic resistance-guided therapy vs empirical therapy for eradication of refractory Helicobacter pylori infection in randomized controlled trials.

METHODS

We performed 2 multicenter, open-label trials of patients with H pylori infection (20 years or older) failed by 2 or more previous treatment regimens, from October 2012 through September 2017 in Taiwan. The patients were randomly assigned to groups given genotypic resistance-guided therapy for 14 days (n = 21 in trial 1, n = 205 in trial 2) or empirical therapy according to medication history for 14 days (n = 20 in trial 1, n = 205 in trial 2). Patients received sequential therapy containing esomeprazole and amoxicillin for the first 7 days, followed by esomeprazole and metronidazole, with levofloxacin, clarithromycin, or tetracycline (doxycycline in trial 1, tetracycline in trial 2) for another 7 days (all given twice daily) based on genotype markers of resistance determined from gastric biopsy specimens (group A) or empirical therapy according to medication history. Resistance-associated mutations in 23S ribosomal RNA or gyrase A were identified by polymerase chain reaction with direct sequencing. Eradication status was determined by ¹³C-urea breath test. The primary outcome was eradication rate.

RESULTS

H pylori infection was eradicated in 17 of 21 (81%) patients receiving genotype resistance-guided therapy and 12 of 20 (60%) patients receiving empirical therapy (P = .181) in trial 1. This trial was terminated ahead of schedule due to the low rate of eradication in patients given doxycycline sequential therapy (15 of 26 [57.7%]). In trial 2, H pylori infection was eradicated in 160 of 205 (78%) patients receiving genotype resistance-guided therapy and 148 of 205 (72.2%) patients receiving empirical therapy (P = .170), according to intent to treat analysis. The frequencies of adverse effects and compliance did not differ significantly between groups.

CONCLUSIONS

Properly designed empirical therapy, based on medication history, is an acceptable alternative to genotypic resistance-guided therapy for eradication of refractory H pylori infection after consideration of accessibility, cost, and patient preference. ClinicalTrials.gov ID: NCT01725906.

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.

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.

Concomitant, bismuth quadruple, and 14-day triple therapy in the first-line treatment of Helicobacter pylori: a multicentre, open-label, randomised trial

BACKGROUND

Whether concomitant therapy is superior to bismuth quadruple therapy or 14-day triple therapy for the first-line treatment of Helicobacter pylori infection remains poorly understood. We aimed to compare the efficacy and safety of 10-day concomitant therapy, 10-day bismuth quadruple therapy, and 14-day triple therapy in the first-line treatment of H pylori.

METHODS

In this multicentre, open-label, randomised trial, we recruited adult patients (aged >20 years) with H pylori infection from nine medical centres in Taiwan. Patients who had at least two positive tests from the rapid urease test, histology, culture, or serology or who had a single positive ¹³C-urea breath test for gastric cancer screening were eligible for enrolment. Patients were randomly assigned (1:1:1) to either concomitant therapy (lansoprazole 30 mg, amoxicillin 1 g, clarithromycin 500 mg, and metronidazole 500 mg, all given twice daily) for 10 days; bismuth quadruple therapy (bismuth tripotassium dicitrate 300 mg four times a day, lansoprazole 30 mg twice daily, tetracycline 500 mg four times a day, and metronidazole 500 mg three times a day) for 10 days; or triple therapy (lansoprazole 30 mg, amoxicillin 1 g, and clarithromycin 500 mg, all given twice daily) for 14 days. A computer-generated permuted block randomisation sequence with a block size of 6 was used for randomisation, and the sequence was concealed in an opaque envelope until the intervention was assigned. Investigators were masked to treatment allocation. The primary outcome was the eradication frequency of H pylori with first-line therapy assessed in the intention-to-treat population. This trial is registered with ClinicalTrials.gov, number NCT01906879.

FINDINGS

Between July 17, 2013, and April 20, 2016, 5454 patients were screened for eligibility. Of these, 1620 patients were randomly assigned in this study. The eradication frequencies were 90·4% (488/540 [95% CI 87·6-92·6]) for 10-day bismuth quadruple therapy, 85·9% (464/540 [82·7-88·6]) for 10-day concomitant therapy, and 83·7% (452/540 [80·4-86·6]) for 14-day triple therapy in the intention-to-treat analysis. 10-day bismuth quadruple therapy was superior to 14-day triple therapy (difference 6·7% [95% CI 2·7-10·7, p=0·001), but not 10-day concomitant therapy. 10-day concomitant therapy was not superior to 14-day triple therapy. The frequency of adverse events was 67% (358/533) in patients treated with 10-day bismuth quadruple therapy, 58% (309/535) in patients treated with 10-day concomitant therapy, and 47% (252/535) in patients treated with 14-day triple therapy.

INTERPRETATION

Bismuth quadruple therapy is preferable to 14-day triple therapy in the first-line treatment in the face of rising prevalence of clarithromycin resistance. Concomitant therapy given for 10 days might not be optimum and a longer treatment length should be considered.

FUNDING

National Taiwan University Hospital and Ministry of Science and Technology of Taiwan.

Levofloxacin Sequential Therapy vs Levofloxacin Triple Therapy in the Second-Line Treatment of Helicobacter pylori: A Randomized Trial

OBJECTIVES

The efficacy of levofloxacin triple therapy has fallen below 80% in the second-line treatment of Helicobacter pylori (H. pylori). We aimed to assess whether the levofloxacin sequential therapy is more effective than levofloxacin triple therapy in the second-line treatment.

METHODS

This open-label, randomized, multicenter trial was conducted between 2012 and 2015. H. pylori-infected subjects who failed from clarithromycin-based regimens (N=600) were randomized (1:1) to receive levofloxacin sequential therapy (LS: lansoprazole and amoxicillin for the first 5 days, followed by lansoprazole, levofloxacin, and metronidazole for another 5 days) or levofloxacin triple therapy (LT: lansoprazole, amoxicillin, and levofloxacin for 10 days). Successful eradication was defined as negative (13)C-urea breath test at least 6 weeks after treatment. Our primary outcome was the eradication rate by intention-to-treat (ITT) and per-protocol (PP) analyses. Antibiotic resistance was determined by agar dilution test.

RESULTS

The prevalence of clarithromycin, levofloxacin, and metronidazole resistance was 60, 17.6, and 36.9%, respectively. The eradication rates of LS and LT were 84.3% (253/300) and 75.3% (226/300), respectively, in the ITT analysis (P=0.006) and 86.3% (253/293) and 78.8% (223/283), respectively, in the PP analysis (P=0.021). The efficacies of both LS and LT were affected by levofloxacin resistance. The secondary resistance of levofloxacin was 66.7 and 73.9% after LS and LT, respectively. The efficacies of LS and LT were not affected by the CYP2C19 polymorphism.

CONCLUSIONS

Levofloxacin sequential therapy was more effective than levofloxacin triple therapy, and it is recommended in the second-line treatment for H. pylori (

TRIAL REGISTRATION NUMBER

NCT01537055).

Non-invasive screening for colorectal cancer in Asia

There is an increasing trend of colorectal cancer incidence in Asia and nearly 45% of CRC cases worldwide occur in Asia therefore screening for CRC becomes an urgent task. Stool-based tests, including guaiac fecal occult blood test (gFOBT) and fecal immunochemical test (FIT), can select subjects at risk of significant colorectal neoplasms from the large target population thus are currently the most commonly used non-invasive screening tool in large population screening programs. FIT has the advantage over gFOBT in terms of higher sensitivity for early neoplasms, the ability to provide high-throughput automatic analysis, and better public acceptance thus greater effectiveness on reducing CRC mortality and incidence is expected. Owing to the large target population and constrained endoscopic capacity and manpower, FIT is nowadays the most popular CRC screening test in Asia. Some Asian countries have launched nationwide screening program in the past one or two decades but also encountered some challenges such as low screening participation rate, low verification rate after positive stool tests, low public awareness, and insufficient manpower. In addition, some controversial or potential future research issues are also addressed in this review.

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

BACKGROUND & AIMS

Metabolic syndrome is associated with increased risk of colorectal neoplasm, but little is known about its effects on the occurrence of neoplasm after colonoscopy. We investigated the effects of metabolic syndrome on the risk of advanced neoplasm after colonoscopy.

METHODS

We performed a prospective study of 4483 subjects age 50 years and older who underwent screening and surveillance colonoscopies as part of an annual health check-up at National Taiwan University Hospital. Baseline demographic data and colonoscopic findings were recorded. Subjects with either advanced adenoma or 3 or more adenomas detected at baseline were classified as high risk; those with fewer than 3 nonadvanced adenomas were classified as low risk; and those without any neoplastic lesions were classified as normal. The cumulative risk of detecting an advanced neoplasm during surveillance colonoscopies (3 and 5 years later) was correlated with risk group and metabolic syndrome. Hazard ratios (HRs) were calculated for occurrence of neoplasm according to baseline colonoscopic findings and clinical risk factors, including metabolic syndrome.

RESULTS

Advanced neoplasms were detected during the surveillance colonoscopies in 1.3% of subjects in the normal group and in 2.4% of those in the low-risk group at 5 years, and in 8.5% of subjects in the high-risk group at 3 years. Subjects with metabolic syndrome had a significantly higher risk for subsequent advanced neoplasms (P < .0001). After stratification based on findings from baseline colonoscopies, the risk for neoplasm was significant in the normal (P < .001) and low-risk groups (P = .04), but not in the high-risk group (P = .48). In Cox regression analysis, metabolic syndrome had significant effects on the risk for advanced neoplasms in the normal (HR, 2.07; 95% confidence interval, 1.13-3.81) and low-risk groups (HR, 2.34; 95% confidence interval, 1.01-5.41), but not in the high-risk group.

CONCLUSIONS

Metabolic syndrome is a significant risk factor for occurrence of an advanced adenoma after a negative or low-risk finding from a baseline colonoscopy. Metabolic syndrome should be considered in risk stratification for surveillance intervals.

Helicobacter Pylori Infection is Positively Associated with Metabolic Syndrome in Taiwanese Adults: a Cross-Sectional Study

BACKGROUND

Helicobacter pylori infection and metabolic syndrome have been reported to be positively associated. However, only a few studies have focused on this issue, and H. pylori serum antigen was used to diagnose infection in most of them. We aimed to investigate the association between metabolic syndrome factors and H. pylori infection, as diagnosed via a (13)C-urea breath test.

MATERIALS AND METHODS

This cross-sectional study consisted of 3578 subjects (18-64 years old) enrolled from one health management center between 2008 and 2013. H. pylori infection was defined as a positive urea breath test. The risk of metabolic syndrome from H. pylori infection was assessed using a multiple logistic regression model.

RESULTS

The prevalence of the H. pylori was similar in both genders (20.6% in men and 19.7% in women). H. pylori -infected participants had significantly higher body mass index, fasting glucose, low-density lipoprotein, and triglycerides, and lower high-density lipoprotein (p < 0.05), than uninfected ones (p < 0.05). The prevalence of metabolic syndrome was higher in H. pylori -infected subjects than uninfected ones (men: 12.4% vs. 7.4%, p < 0.001; women: 7.4% vs. 2.5%, p < 0.001). Furthermore, H. pylori infection prevalence increased with metabolic score (P for trend <0.001, both sexes). Moreover, the association between metabolic syndrome and UBT positivity was significant in females (OR 1.91, 95% CI:1.03-3.53), but only borderline significant in males (OR 1.38, 95% CI: 0.97-1.95).

CONCLUSION

H. pylori infection is positively associated with metabolic syndrome, especially in females. The causal relationship between H. pylori infection and metabolic syndrome warrants further investigation.

Carbon dioxide insufflation can significantly reduce toilet use after colonoscopy: a double-blind randomized controlled trial

BACKGROUND AND STUDY AIMS

Carbon dioxide (CO2) insufflation during colonoscopy can significantly decrease abdominal pain and bloating after the procedure, but its impact on the frequency and duration of toilet use remains unknown. The aim of this study was to assess the impact of CO2 insufflation on toilet use after screening colonoscopy.

METHODS

From 138 average-risk individuals who underwent screening colonoscopy during March to August 2013, 120 were enrolled and randomized to receive either CO2 or air insufflation at colonoscopy. Both the colonoscopist and participant were blinded to the type of gas used. Abdominal pain and distension were assessed using a visual analog scoring system. The frequency and duration of toilet visits during a 2-hour postcolonoscopy period were recorded using a radiofrequency identification system.

RESULTS

Baseline characteristics were similar in both groups in terms of age, sex, and procedure time. In the 2 hours after colonoscopy, 50 participants (83 %) in the air group and 18 participants (30 %) in the CO2 group (P < 0.001) used the toilet at least once. The mean (± SD) duration of each toilet visit was 5.93 ± 4.65 minutes in the air group and 1.53 ± 2.84 minutes in the CO2 group (P < 0.001). The abdominal discomfort score was lower in the CO2 group than in the air group both at the end of the colonoscopy (P < 0.001) and 2 hours later (P < 0.001).

CONCLUSION

Insufflation with CO2 can significantly reduce abdominal discomfort and toilet use after colonoscopy. Use of this technique may help reduce patient burden and allow more efficient use of space in the endoscopy unit.

Predictors of in-hospital mortality after acute variceal bleeding in patients with hepatocellular carcinoma and concurrent main portal vein thrombosis

BACKGROUND AND AIM

Risk factors for acute variceal bleeding in patients with hepatocellular carcinoma (HCC) and concurrent main portal vein thrombosis (PVT) remain unclear. We aimed to determine risk factors of in-hospital mortality after acute variceal bleeding for HCC patients with concurrent main PVT.

METHODS

We conducted a retrospective analysis of 102 HCC patients (83% men and 17% women) with concurrent main PVT and acute variceal bleeding. All patients received emergent endoscopy to define the bleeding source. Multivariable Cox proportional hazard regression analysis consisting of clinical, laboratory, and endoscopic parameters was performed to identify predictive factors for intrahospital mortality.

RESULTS

Twenty-eight (27.5%) patients died within admission. The median survival of all patients was 56 days. Multivariable Cox proportional hazard regression analyses revealed Child-Pugh score (adjusted hazard ratio [aHR]: 1.29 for each point; 95% confidence interval [CI]: 1.11-1.50), active bleeding on index endoscopy (aHR: 7.50; 95% CI: 3.05-18.4), esophageal varices as the bleeder (compared with gastric varices, aHR: 14.3; 95% CI: 3.12-66.1), failure to control bleeding (aHR: 38.0; 95% CI: 7.44-194), and serum creatinine (aHR: 1.28 for each increase of 1 mg/dL; 95% CI: 1.09-1.50) independently predicted in-hospital mortality.

CONCLUSIONS

Hepatic reserve, active bleeding on index endoscopy, failure to control bleeding, esophageal varices as the bleeder when compared with gastric varices, and renal function were independent predictive factors for in-hospital mortality in HCC patients with acute variceal bleeding and concurrent main PVT.