Korean guidelines for colorectal cancer screening and polyp detection

Disability-adjusted life years for colorectal cancer in China, 2017-2030: A prevalence-based analysis focusing on the impact of screening coverage and the application of local weights

BACKGROUND

Most studies have evaluated disability-adjusted life years (DALYs) of colorectal cancer (CRC) patients based on a set of generic disability weights (DWs). This study aimed to apply local CRC-stage-specific DWs to estimate the burden of DALYs for CRC (CRC-DALYs) in populations in China and consider the influence of local screening coverage of CRC.

METHODS

A prevalence-based model was constructed using data from various sources. Years lived with disability (YLDs) were estimated mainly via cumulative prevalence data (based on CRC incidence rates, population numbers, and survival rates), stage-specific proportions of CRC, and DWs of the local population. Years of life lost (YLLs) were calculated based on the CRC mortality rates and standard life expectancies. CRC incidence and mortality rates for the years 2020, 2025, and 2030 were estimated by joinpoint regression, and the corresponding DALYs were predicted. The main assumption was made for CRC screening coverage. Sensitivity analysis was used to assess the impact of population, DWs, and coverage.

RESULTS

In 2017, among the Chinese population, the estimated number of CRC-DALYs was 4,303,314 (11.8% for YLDs). If CRC screening coverage rate in China (2.3%) remains unchanged, the overall DALYs in 2030 are predicted to increase by 37.2% (45.1% of those aged ≥65 years). More optimistically, the DALYs would then decrease by 0.7% in 2030 (from 5,902,454 to 5,860,200) if the coverage could be increased to 25.0%. A sensitivity analysis revealed that using local DWs would change the base-case values by 5.7%.

CONCLUSIONS

The estimated CRC-DALYs in China using population-specific DWs were considerably lower (with a higher percentage of YLDs) than the global burden of disease (GBD) estimates (5,865,004, of 4.6% for YLDs), suggesting the impact extent of applying local parameters. Sustainable scale-up CRC screening needs to be in place to moderate the growth trend of CRC-DALYs in China.

The Economic Burden of Colorectal Cancer in Type 2 Diabetes Mellitus (T2DM) in Shanghai, China

OBJECTIVE

This study aimed to analyze disease cost levels among colorectal cancer (CRC) patients, examining differences in disease costs between those with type 2 diabetes mellitus (T2DM) and those without T2DM while considering various demographic characteristics.

METHODS

The study included respondents from colorectal cancer patients diagnosed and managed within the population-based cancer registry system of the Shanghai Municipal Center for Disease Control and Prevention from 2020 to 2022. Diabetic colorectal cancer cases were matched with nondiabetic colorectal cancer controls using propensity scores, maintaining a 1:1 ratio between cases and controls; bias for the majority of the matched variables is below 10%. Direct, indirect, and intangible costs were estimated for study subjects.

RESULTS

After propensity score matching, the analysis encompassed 376 cases of T2DM-related CRC and 376 non-T2DM CRC cases. The T2DM group exhibited higher direct medical costs (¥57,059.65 vs. ¥48,933.93, p < 0.05), direct nonmedical costs (¥9292.45 vs. ¥7969.35), indirect costs (¥300.13 vs. ¥241.11), intangible costs (¥3601.70 vs. ¥2631.96), and total disease costs (¥70,253.93 vs. ¥59,776.36, p < 0.05) compared to the non-T2DM group. In Stage II CRC, direct medical costs were ¥74,008.39 for the T2DM group versus ¥57,368.84 for the non-T2DM group. Among surgical patients, direct medical costs were ¥57,658.81 for the T2DM group versus ¥1337.00 for the non-T2DM group, and ¥49,061.52 for the non-T2DM surgical group versus ¥1089.00 for the non-T2DM nonsurgical group.

CONCLUSION

Colorectal cancer imposes a substantial economic burden. Patients with CRC and concurrent T2DM experience a higher economic burden compared to nondiabetic patients. Notably, individuals with both T2DM and Stage II cancer face a significantly higher economic burden, whereas surgical patients exhibit a significantly greater disease burden than nonsurgical patients. Efforts should concentrate on primary prevention and secondary prevention to alleviate the economic burden associated with colorectal cancer.

Colonic Polyp Study: Differences in Adenoma Characteristics Based on Colonoscopy History over 5-Year Follow-Up Period

Background: Timely detection and removal of colonic adenomas are critical for preventing colorectal cancer. Methods: This study analyzed differences in colonic adenoma characteristics based on colonoscopy history by reviewing the medical records of 14,029 patients who underwent colonoscopy between January and June 2020 across 40 primary medical institutions in Korea. Results: Adenoma and advanced neoplasia characteristics varied significantly with colonoscopy history (p < 0.05). In the first-time colonoscopy group, adenomas were more frequent in the sigmoid colon (S-colon) and rectum, with Is features and non-granular laterally spreading tumors. Advanced neoplasia was also more common in the S-colon and rectum, with Is and advanced-type features. In the <5-year group, adenomas were predominantly found in the transverse colon (T-colon) and descending colon (D-colon), with IIa and IIb features. Advanced neoplasia in this group was more frequent in the cecum and T-colon, with IIa and IIb features and laterally spreading tumors. In the ≥5-year group, adenomas were more commonly located in the ascending colon (A-colon) and cecum, with Ip features, while advanced neoplasia was more frequent in the A-colon and D-colon, also with Ip features. Conclusions: Although every segment of the colorectum should be carefully observed regardless of colonoscopy history, these findings suggest that prioritizing specific colonic segments for examination based on colonoscopy history may improve adenoma detection rates and reduce the incidence of colorectal cancer. However, further large-scale, prospective studies are needed to confirm these findings and support their application in clinical practice.

Colorectal cancer screening guidelines for average-risk and high-risk individuals: A systematic review

AIMS

This review aims to summarize the different colorectal cancer guidelines for average-risk and high-risk individuals from various countries.

METHODS

A comprehensive literature search regarding guidelines, consensus recommendations, or position statements about colorectal cancer screening published within the last 10 years (1st January 2012 to 27th August 2022), was performed at EBSCOhost, JSTOR, PubMed, ProQuest, SAGE, and ScienceDirect.

RESULTS

A total of 18 guidelines were included in this review. Most guidelines recommended screening between 45 and 75 years for average-risk individuals. Recommendations regarding colorectal cancer screening in high-risk individuals were more varied and depended on the risk factor. For high-risk individuals with a positive family history of colorectal cancer or advanced colorectal polyp, screening should begin at age 40. Some frequently suggested screening modalities in order of frequency are colonoscopy, FIT, and CTC. Furthermore, several screening intervals were suggested, including colonoscopy every 10 years for average-risk and every 5-10 years for high-risk individuals, FIT annually in average-risk and every 1-2 years in high-risk individuals, and CTC every five years for all individuals.

CONCLUSION

All individuals with average-risk should undergo colorectal cancer screening between 45 and 75. Meanwhile, individuals with higher risks, such as those with a positive family history, should begin screening at age 40. Several recommended screening modalities were suggested, including colonoscopy every 10 years in average-risk and every 5-10 years in high-risk, FIT annually in average-risk and every 1-2 years in high-risk, and CTC every five years.

Evaluation of the "Burgenland PREvention trial of colorectal cancer Disease with ImmunologiCal Testing" (B-PREDICT)-a population-based colorectal cancer screening program

BACKGROUND

The colorectal cancer (CRC) screening program B-PREDICT is a population based invited two stage screening project using a faecal immunochemical test (FIT) for initial screening followed by a colonoscopy for those with a positive FIT. B-PREDICT was compared with the opportunistic screening colonoscopy (OPP-COL), performed in course of the nationwide screening program.

METHODS

Within B-PREDICT all residents of the Austrian federal state Burgenland, aged between 40 and 80 are annually invited to FIT testing. All individuals who underwent initial colonoscopy in Burgenland between 01/2003 and 12/2014, were included in this study. Individuals from the FIT-triggered invited screening program B-PREDICT were compared with those from the non-FIT triggered OPP-COL.

RESULTS

15 133 individuals from B-PREDICT were compared to 10 045 individuals with OPP-COL. CRC detection rates were 1.34% (CI-95%, [1.15; 1.52]) in B-PREDICT compared to 0.54% in OPP-COL (95%-CI, [0.39; 0.68] p < 0.001). The decrease in the age standardized incidence rates of CRC was more pronounced in the population screened with FIT than in the general population screened with colonoscopy. Changes in incidence rates per year were -4.4% (95%-CI, [-5.1; -3.7]) vs. -1.8% (95%-CI, [-1.9; -1.6] p < 0.001).

CONCLUSIONS

B-PREDICT shows a two-fold higher detection rate of CRC as well as HRA compared to OPP-COL.

Trends in colorectal cancer incidence according to an increase in the number of colonoscopy cases in Korea

BACKGROUND

The incidence of colorectal cancer (CRC) and preinvasive CRC (e.g., early colon cancer and advanced adenoma) is gradually increasing in several countries.

AIM

To evaluate the trend in incidence of CRC and preinvasive CRC according to the increase in the number of colonoscopies performed in Korea.

METHODS

This retrospective cohort study enrolled Korean patients from 2002 to 2020 to evaluate the incidence of CRC and preinvasive CRC, and assess the numbers of diagnostic colonoscopies and colonoscopic polypectomies. Colonoscopy-related complications by age group were also determined.

RESULTS

The incidence of CRC showed a rapid increase, then decreased after 2012 in the 50-75 year-age group. During the study period, the rate of incidence of preinvasive CRC increased at a similar level in patients under 50 and 50-75 years of age. Since 2009, the increase has been rapid, showing a pattern similar to the increase in colonoscopies. The rate of colonoscopic polypectomy in patients aged under 50 was similar to the rate in patients over 75 years of age after 2007. The rate of complications after colonoscopy and related deaths within 3 mo was high for those over 75 years of age.

CONCLUSION

The diagnosis of preinvasive CRC increased with the increase in the number of colonoscopies performed. As the risk of colonoscopy-related hospitalization and death is high in the elderly, if early lesions at risk of developing CRC are diagnosed and treated under or at the age of 75, colonoscopy-related complications can be reduced for those aged 76 years or over.

Systematic review of shared decision-making in guidelines about colorectal cancer screening

INTRODUCTION

We aimed to systematically evaluate quality of shared decision-making (SDM) in colorectal cancer (CRC) screening clinical practice guidelines (CPGs) and consensus statements (CSs).

METHODS

Search for CRC screening guidances was from 2010 to November 2021 in EMBASE, Web of Science, MEDLINE, Scopus and CDSR, and the World Wide Web. Three independent reviewers and an arbitrator rated the quality of each guidance using a SDM quality assessment tool (maximum score: 31). Reviewer agreement was 0.88.

RESULTS

SDM appeared in 41/83 (49.4%) CPGs and 9/19 (47.4%) CSs. None met all the quality criteria, and 51.0% (52/102) failed to meet any quality items. Overall compliance was low (mean 1.63, IQR 0-2). Quality was better in guidances published after 2015 (mean 1, IQR 0-3 vs. mean 0.5, IQR 0-1.5; p = 0.048) and when the term SDM was specifically reported (mean 4.5, IQR 2.5-4.5 vs. mean 0.5, IQR 0-1.5; p < 0.001). CPGs underpinned by systematic reviews showed better SDM quality than consensus (mean 1, IQR 0-3 vs. mean 0, IQR 0-2, p = 0.040).

CONCLUSION

SDM quality was suboptimal and mentioned in less than half of the guidances, and recommendations were scarce. Guideline developers should incorporate evidence-based SDM recommendations in guidances to underpin the translation of evidence into practice.

Apurinic/apyrimidinic endonuclease 1 is associated with poor prognosis after curative resection followed by adjuvant chemotherapy in patients with stage III colon cancer

Purpose

Apurinic/apyrimidinic endonuclease 1 (APE1) is a key enzyme involved in the base excision repair pathway. It also has redox activity and maintains various transcription factors in an active reduced state. APE1 may be associated with chemoresistance. In the present study, we first investigated the expression level of APE1 protein and its correlation with oncologic outcomes of oxaliplatin-based chemotherapy in patients with stage III colon cancer. Further, we investigated the effects of human APE1 siRNA on the sensitivity of oxaliplatin in SNU-C2A colon cancer cells.

Methods

Tissue specimens from tumor and normal colon of 33 patients with stage III colon cancer were obtained from 2006 to 2009. The patients received at least eight cycles of oxaliplatin-based chemotherapy. APE1 expression was analyzed by immunohistochemistry and Western blotting using a cultured SNU-C2A cell line. Cell viability and apoptosis were determined by Cell Counting Kit-8 and caspase-3 cleavage using Western blotting.

Results

All the colon cancer tissues showed APE1 staining in the nucleus, whereas all the normal colon tissues were negative for APE1 staining in the cytoplasm. The group with a higher expression of APE1 demonstrated poorer prognosis than the group with low expression (P=0.026 for overall survival and P=0.021 for disease-free survival). Treatment with oxaliplatin resulted in a dose-dependent increase in APE1 expression in SNU-C2A cells. APE1 siRNA significantly enhanced oxaliplatin-induced growth inhibition, and also increased oxaliplatin-induced apoptosis in SNU-C2A cells.

Conclusion

APE1 could be considered a prognostic factor in colon cancer patients treated with oxaliplatin-based chemotherapy.

Disparities in Recommendations for Colorectal Cancer Screening Among Average-Risk Individuals: An Ecobiosocial Approach

Regardless of the high global burden of colorectal cancer (CRC), the uptake of CRC screening varies across countries. This systematic review aimed to provide a picture of the disparities in recommendations for CRC screening in average-risk individuals using an ecobiosocial approach. It was reported according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The literature search was conducted through Scopus, Web of Science, PubMed, and EBSCOHost. Full-text guidelines which were published between 2011 and 2021, along with guidelines which provided recommendations on CRC screening in average-risk individuals, were included in the review. However, guidelines focusing only on a single screening modality were excluded. Fourteen guidelines fulfilling the eligibility criteria were retained for the final review and analysis. Quality assessment of each guideline was performed using the AGREE II instrument. Disparities in guidelines identified in this review were classified into ecological (screening modalities and strategies), biological (recommended age, gender and ethnicities), and social (smoking history, socioeconomic status, and behavior) factors. In general, unstandardized practices in CRC screening for average-risk individuals are likely attributable to the inconsistent and non-specific recommendations in the literature. This review calls on stakeholders and policymakers to review the existing colorectal cancer screening practices and pursue standardization.

Association of HLA-G 3'UTR polymorphisms and haplotypes with colorectal cancer susceptibility and prognosis

Human leukocyte antigen (HLA)-G has been considered as an immune modulator in several types of cancers. Its genetic polymorphisms may potentially affect the risk of developing colorectal cancer (CRC). The overall purpose of this study was to analyze the implication of HLA-G 3'untranslated region (3'UTR) polymorphisms particularly 14 pb insertion/deletion (Ins/Del; rs371194629) and + 3142C/G (rs1063320) in CRC susceptibility and progression. A comparative analysis between patients (N = 233) and controls (N = 241) demonstrated that Del allele (Odds Ratios (OR) = 1.41, 95% CI = 1.091-1.819, p = 0.008), the homozygous Del/Del genotype (OR = 1.80, 95% CI = 1.205-2.664, p = 0.003) and the codominant C/G genotype (OR = 1.59, 95% CI = 1.106-2.272, p = 0.013) were associated to CRC risk. As expected, the DelG haplotype was associated with CRC susceptibility (OR = 1.47, 95% CI = 1.068-2.012, p = 0.018). Assessment of patients' survival by Kaplan-Meier analysis indicated that the Del allele and the homozygous Del/Del genotype were associated with reduced event free survival (EFS) (Respectively, p = 0.009 and p = 0.05). Interestingly, the Del allele and the homozygous Del/Del genotype have been revealed as independent prognostic factors for poor EFS in patients with CRC. Additionally, haplotypes analysis revealed that DelG haplotype was linked with significant increase in CRC risk (log-rank; EFS: p = 0.02). Inversely, the InsC haplotype was associated with a significant reduced CRC risk (log-rank; Overall survival (OS): p < 10^-6; EFS: p = 0.01). Multivariate Cox regression analysis revealed that the InsC haplotype was independently associated with significantly longer EFS (p = 0.021, HR = 0.636, 95% CI = 0.433-0.935). These findings support the implication of HLA-G polymorphisms in the CRC susceptibility suggesting HLA-G as a potent prognostic and predictive indicator for CRC. Insight into mechanisms underlying HLA-G polymorphisms could allow for the development of targeted care for CRC patients according to their genetic profile.

Tumor Size >5 cm and Harvested LNs <12 Are the Risk Factors for Recurrence in Stage I Colon and Rectal Cancer after Radical Resection

Simple Summary

We analyzed the data from 1952 patients with stage I colorectal cancer to evaluate the risk factors for recurrence and survival rates. In the entire cohort, the recurrence rate was 4.6%. There were some differences in the risk factors for recurrence between colon and rectal cancer in stage I colorectal cancer. Left-sided tumors, T2, tumor size >5 cm, and lymphovascular invasion were independent risk factors of colon cancer recurrence. Male, preoperative carcinoembryonic antigen (CEA) ≥2.5 ng/mL, and harvested lymph nodes (LNs) <12 were independently associated with recurrence of rectal cancer. Even though patients with early-stage CRC underwent curative resection, survival sharply decreased in cases of recurrence. Our findings could suggest more aggressive surveillance for patients with an increased risk of recurrence.

Abstract

Recurrence can still occur even after radical resection of stage I colorectal cancer (CRC). This study aimed to identify subgroups with a high risk for recurrence in the stage I CRC. We retrospectively reviewed prospectively collected data of 1952 patients with stage I CRC after radical resection between 2002 and 2017 at our institute. 1398 (colon, 903 (64.6%), rectum, 495 (35.4%)) were eligible for analysis. We analyzed the risk factors for recurrence and survival. During the follow-up period (median: 59 months), 63 (4.6%) had a recurrence. The recurrence rate of rectal cancer was significantly higher than that of colon cancer (8.5% vs. 2.3%). Left-sided tumors, T2, tumor size >5 cm, and lymphovascular invasion were independent risk factors of colon cancer recurrence. Male, preoperative carcinoembryonic antigen (CEA) ≥2.5 ng/mL, and harvested lymph nodes (LNs) <12 were independently associated with recurrence of rectal cancer. Recurrence affected OS (5-year OS: 97.1% vs. 67.6%). Despite curative resection, survival sharply decreased with recurrence. The risk factors for recurrence were different between colon and rectal cancer. Patients with a higher risk for recurrence should be candidates for more aggressive surveillance, even in early-stage CRC.

Optimal postoperative surveillance strategies for stage III colorectal cancer

BACKGROUND

Optimal surveillance strategies for stage III colorectal cancer (CRC) are lacking, and intensive surveillance has not conferred a significant survival benefit.

AIM

To examine the association between surveillance intensity and recurrence and survival rates in patients with stage III CRC.

METHODS

Data from patients with pathologic stage III CRC who underwent radical surgery between January 2005 and December 2012 at Asan Medical Center, Seoul, Korea were retrospectively reviewed. Surveillance consisted of abdominopelvic computed tomography (CT) every 6 mo and chest CT annually during the 5 year follow-up period, resulting in an average of three imaging studies per year. Patients who underwent more than the average number of imaging studies annually were categorized as high intensity (HI), and those with less than the average were categorized as low intensity (LI).

RESULTS

Among 1888 patients, 864 (45.8%) were in HI group. Age, sex, and location were not different between groups. HI group had more advanced T and N stage (P = 0.002, 0.010, each). Perineural invasion (PNI) was more identified in the HI group (21.4% vs 30.3%, P < 0.001). The mean overall survival (OS) and recurrence-free interval (RFI) was longer in the LI group (P < 0.001, each). Multivariate analysis indicated that surveillance intensity [odds ratio (OR) = 1.999; 95% confidence interval (CI): 1.680-2.377; P < 0.001], pathologic T stage (OR = 1.596; 95%CI: 1.197-2.127; P = 0.001), PNI (OR = 1.431; 95%CI: 1.192-1.719; P < 0.001), and circumferential resection margin (OR = 1.565; 95%CI: 1.083-2.262; P = 0.017) in rectal cancer were significantly associated with RFI. The mean post-recurrence survival (PRS) was longer in patients who received curative resection (P < 0.001). Curative resection rate of recurrence was not different between HI (29.3%) and LI (23.8%) groups (P = 0.160). PRS did not differ according to surveillance intensity (P = 0.802).

CONCLUSION

Frequent surveillance with CT scan do not improve OS in stage III CRC patients. We need to evaluate role of other surveillance method rather than frequent CT scans to detect recurrence for which curative treatment was possible because curative resection is the important to improve post-recurrence survival.

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

Background/Aims

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

Methods

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

Results

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

Conclusions

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

Real-World Use of Colonoscopy in an Older Population: A Nationwide Standard Cohort Study Using a Common Data Model

BACKGROUNDS AND AIMS

Rapid population aging is considered to be a major factor in increased colonoscopy use in Korea. However, real-world use of colonoscopy in older populations is rarely evaluated using Korean databases.

METHODS

We conducted a retrospective, observational cohort study of individuals aged over 20 years between 2012 and 2017. We used the Health Insurance Review and Assessment-National Patient Samples database, previously converted to the standardized Observational Medical Outcomes Partnership-Common Data Model. The use of diagnostic colonoscopy and colonoscopic polypectomy was evaluated, stratified by age group and sex.

RESULTS

During the study period, we captured data from the database on 240,406 patients who underwent diagnostic colonoscopy and 88,984 who underwent colonoscopic polypectomy. During the study period, use of diagnostic colonoscopy and colonoscopic polypectomy steadily increased, but both procedures were most significantly increased in the 65- to 85-year group compared to other age groups (p < 0.05). Average ages for both procedures significantly increased in the most recent 3 years (p < 0.05). Polypectomy rates for men plateaued in the 50- to 64-year age group, but rates for women steadily increased up to the 65- to 85-year group. Polypectomy rates were higher for men than for women in all index years.

CONCLUSIONS

The use of diagnostic colonoscopy and colonoscopic polypectomy significantly increased in the 65- to 85-year age group. Our findings suggest that more available colonoscopy resources should be allocated to older populations, considering the aging society in Asian countries.

Cecal intubation time in screening colonoscopy

The time required to intubate the cecum varies. The aim of this study was to determine whether demographic and anthropometric factors, such as body mass index (BMI), percent body fat, muscle mass, and fat mass, affect the cecal intubation time (CIT) during complete colonoscopy.A retrospective chart review of 1229 patients (aged 40-80 years) was performed. These patients underwent average-risk screening colonoscopies performed by expert gastroenterologists at Health Check-up Center, Seoul National University Bundang Hospital, during a health check-up. We collected data on age, sex, BMI, percent body fat, muscle mass, fat mass, history of prior abdominal or pelvic surgery, CIT, and bowel preparation quality (Boston Bowel Preparation Scale [BBPS] score).Of the 1229 patients, 62% were men. The mean age was 55 years, and the mean BMI was 24 kg/m2. The median CIT was 5 min. The patients were categorized into two groups according to CIT: easy colonoscopy (CIT ≤ 10 min) and difficult colonoscopy (CIT > 10 min). In univariate analysis, CIT was prolonged by the following factors: older age, poor bowel preparation, lower BMI, lower percent body fat, and less fat mass. Multivariate analysis showed that anthropometric indices including BMI, percent body fat, muscle mass, and fat mass were not significant factors for CIT. Older age (≥ 70 years) (odds ratio [OR]: 2.272, 95% confidence interval [CI]: 1.056-4.890, P = .036) and poor bowel preparation (BBPS score ≤ 5) (OR: 3.817, 95% CI: 1.866-7.808, P = .000) were found to be correlated with difficult colonoscopy.Our study suggests that anthropometric indices including BMI, percent body fat, muscle mass, and fat mass are not associated with significantly different CIT. Furthermore, sex and prior abdominal or pelvic surgery are not useful factors for a prolonged CIT. Older age (≥ 70 years) and poor bowel preparation (BBPS score ≤ 5) are significant variables predicting the CIT of expert gastroenterologists.

Risk of developing metachronous advanced colorectal neoplasia after resection of low-risk diminutive versus small adenomas

BACKGROUND AND AIMS

Current postpolypectomy guidelines classify 1 to 2 diminutive (1-5 mm) nonadvanced adenomas (NAAs) and 1 to 2 small (6-9 mm) NAAs as low-risk adenomas and recommend the same surveillance interval for both lesions. We compared the risk of metachronous advanced colorectal neoplasia (ACRN) for both groups.

METHODS

We studied 8602 patients who underwent removal of ≥1 NAA and follow-up colonoscopic surveillance. Patients were categorized into 4 groups based on size and number of baseline NAAs: group 1, ≤2 diminutive NAAs (n = 6379); group 2, ≤2 small NAAs (n = 1672); group 3, ≥3 diminutive NAAs (n = 293); and group 4, ≥3 small NAAs (n = 258). Size was classified based on the largest NAA.

RESULTS

The 5-year cumulative incidence rates of metachronous ACRN in groups 1, 2, 3, and 4 were 2.7%, 5.1%, 10.7%, and 15.1%, respectively. Groups 2, 3, and 4 had a higher risk of metachronous ACRN than group 1. Compared with group 1, the adjusted hazard ratios for metachronous ACRN were 2.06 (95% confidence interval [CI], 1.46-2.91) for group 2, 2.75 (95% CI, 1.53-4.96) for group 3, and 4.49 (95% CI, 2.62-7.70) for group 4. However, the risk of metachronous ACRN was not significantly different between groups 3 and 4 (adjusted hazard ratio, 1.62; 95% CI, .76-3.44).

CONCLUSIONS

Among patients with ≤2 NAAs, patients with 1- to 5-mm NAAs had a lower risk of metachronous ACRN than those with 6- to 9-mm NAAs. The guidelines should consider extending surveillance intervals in patients with ≤2 diminutive NAAs.

Factors Associated With Colonoscopy Compliance Based on Health Belief Model in a Community-Based Colorectal Cancer Screening Program Shanghai, China

Screening can help early detection of colorectal cancer (CRC) in the general population. However, colonoscopy compliance in screening program is low in China. The study aimed to identify factors associated with colonoscopy compliance based on Health Belief Model (HBM). An investigation was conducted in Huangpu District, Shanghai in 2015. High-risk individuals of CRC received an in-person interview with physicians to fill out a questionnaire. The questionnaires assessing predictors of colonoscopy compliance were collected, and status of colonoscopy participation was determined. Univariate and multiple logistic regression analyses were conducted. Among 2,568 high-risk population (20.68%), 531 subjects underwent colonoscopy. Participants with both risk assessment and fecal immunochemical test positive were most likely to undergo colonoscopy. Based on HBM, colonoscopy compliance was positively associated with higher perceived severity (odds ratio [OR] = 1.05, 95% confidence interval [CI] = [1.00, 1.10]). Higher perceived barriers (OR = 0.97, 95% CI = [0.94, 0.99]), without prior colonoscopy (OR = 0.35, 95% CI = [0.26, 0.47]), not knowing anyone who underwent colonoscopy before (OR = 0.74, 95% CI = [0.58, 0.96]), without health-care provider recommendation on colonoscopy (OR = 0.58, 95% CI = [0.44, 0.77]), and without psychosocial support from someone for colonoscopy (OR = 0.27, 95% CI = [0.21, 0.35]) were shown to be associated with colonoscopy noncompliance. The colonoscopy compliance was low in this CRC screening program in Shanghai, China. The influencing factors were positive results in primary screening, perceived severity, perceived barriers, personal or others' experiences in colonoscopy, health-care provider recommendation, and psychosocial supports. Effective education campaign and facilitated communication between health-care providers and high-risk population were suggested in the future interventions.

[Immunochromatographic test for detection of fecal occult blood.]

The developing and evaluating results of the diagnostic characteristics of an immunochromatographic test for the detection of fecal occult blood (hemoglobin) were presents in the article. The test was approved samples without hemoglobin and model samples containing of standardized preparation of hemoglobin in various concentrations. The developed test system identified hemoglobin in concentrations higher 5 μg / g feces in 97.6% cases, the specificity of the analysis was 100%. The immunochromatographic FOB-test can be used for rapid analysis in the primary screening of colorectal cancer.

Abdominal Obesity is More Predictive of Advanced Colorectal Neoplasia Risk Than Overall Obesity in Men: A Cross-sectional Study

GOALS

We aimed to ascertain whether waist circumference (WC) is associated with risk of colorectal neoplasia (CRN), independent of body mass index (BMI).

BACKGROUND

Although several studies have reported the association between abdominal obesity, measured by WC, and CRN, it remains unclear whether their association is biased by BMI.

STUDY

A cross-sectional study was performed on 154,552 asymptomatic examinees who underwent colonoscopy for a health check-up.

RESULTS

The mean age was 42.6 years, and the proportion of males was 65.2%. The prevalence rate of CRN in subjects in WC quartiles 1, 2, 3, and 4 was 15.6%, 18.1%, 20.4%, and 22.0% among men and 7.8%, 9.4%, 12.2%, and 15.8% among women, respectively. WC and BMI were independent risk factors for overall CRN and nonadvanced CRN in both men and women. In men, the association of BMI with advanced CRN was attenuated to null after adjusting for WC [Q2, Q3, and Q4 vs. Q1; odds ratios (95% confidence intervals), 0.93 (0.79-1.10), 0.85 (0.71-1.03), and 0.99 (0.80-1.22), respectively; Ptrend=0.822], whereas the association of WC with advanced CRN significantly persisted even after adjusting for BMI [Q2, Q3, and Q4 vs. Q1; 1.20 (1.02-1.42), 1.45 (1.20-1.75), and 1.64 (1.32-2.04), respectively; Ptrend<0.001]. In women, neither WC nor BMI was associated with the risk of advanced CRN.

CONCLUSIONS

Abdominal obesity is associated with an increased risk of advanced CRN, independent of overall obesity (BMI) in men. Our findings suggest that abdominal obesity is more strongly predictive of advanced CRN than overall obesity in men.

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.

Colonic Intramucosal Cancer in the Interposed Colon Treated with Endoscopic Mucosal Resection: A Case Report and Review of Literature

Colon interposition is a surgical procedure used for maintenance of luminal conduit after esophagectomy. Although epithelial neoplasia, such as adenoma and adenocarcinoma, may develop in the interposed colon, there are only few case reports on the condition. Due to the rarity of this condition, there is no definite consensus on recommending screening endoscopy for the early detection of neoplasia in the interposed colons. Here, we report a case of intramucosal adenocarcinoma in an interposed colon. Initial endoscopic resection for this tumor failed to accomplish complete resection. A subsequent endoscopic resection was performed 1 month later and complete resection was achieved. Based on our experience and recommendation on screening endoscopy for gastric cancer in Korea, we suggest that regular screening esophagogastroduodenoscopies should be performed following esophagectomy to detect early neoplasia in the stomach and interposed colon and avoid adverse results induced by delayed detection.

Stool-Based miR-92a and miR-144* as Noninvasive Biomarkers for Colorectal Cancer Screening

OBJECTIVES

Current noninvasive screening tests for colorectal cancer (CRC) have insufficient sensitivity. MicroRNA (miRNA) levels in stool have potential as markers for noninvasive screening of CRC. We evaluated the diagnostic value of stool miRNA levels and determined the optimal miRNA subtypes for detecting CRC.

METHODS

Stool samples were collected from 29 patients with CRC and 29 healthy controls. The stool levels of miR-21, miR-92a, miR-200c, miR-144*, miR-135a, miR-135b, miR-106a, and miR-17-3p were determined by real-time quantitative reverse transcription polymerase chain reaction. The sensitivity and specificity of the miRNAs for CRC were determined by receiver operating characteristics analysis.

RESULTS

Among the eight tested miRNAs, the mean stool levels of miR-21, miR-92a, miR-144*, and miR-17-3p differed significantly between the CRC group and the control group (p =0.014, 0.001, <0.001, and 0.008, respectively). The sensitivities and specificities of miR-21, miR-92, miR-144*, and miR-17-3p were 79.3 and 48.3%, 89.7 and 51.7%, 78.6 and 66.7%, and 67.9 and 70.8%, respectively. In a multivariate analysis, miR-92a and miR-144* were significantly associated with the presence of CRC (p = 0.03 and 0.011, respectively).

CONCLUSIONS

The stool levels of miR-92a and miR-144* showed good sensitivity and fair specificity for detection of CRC, and thus may be useful as noninvasive biomarkers for this disease.

[Quality assessment of global guidelines on colorectal cancer screening]

OBJECTIVE

To systematically review and assess the quality of guidelines on colorectal cancer screening worldwide to provide guidance for the development of high-quality colorectal cancer screening guidelines in mainland China.

METHODS

CNKI, WanFang Data, VIP, SinoMed, PubMed, Embase, and Web of Science were systematically searched to identify guidelines on colorectal cancer screening from inception to Jun. 20th, 2018, and so were some websites and major search engines about the development of the guidelines from the existing literature (search date: Aug. 3rd, 2018). Two experienced reviewers independently examined these abstracts and then extracted information, and the Appraisal of Guidelines for Research and Evaluation II (AGREE II) were used to evaluate the methodological quality of these guidelines by four well trained reviewers.

RESULTS

In this study, 46 guidelines published from 1994 to 2018 were finally included in our analysis from 10 countries and 5 regions, among which 5 were from mainland China. The quality of these guidelines was relatively high in domain 1 (scope and purpose) and domain 4 (clarity of presentation), and medium in domain 2 (stakeholder involvement). While in the other three domains (domain 3: rigour of development; domain 5: applicability; domain 6: editorial independence), the results were quite different among these guidelines. The quality of evidence-based guidelines (defined by the criteria based on World Health Organization guideline development handbook) was generally higher than that of the common guidelines. Existing guidelines from mainland China were not evidence-based guidelines, which were of low quality.

CONCLUSION

The colorectal cancer screening guidelines all over the world are generally large in number, low in quality, different in statements, and so are the guidelines in China. There are no evidence-based guidelines in mainland China, which cannot provide effective guidance for colorectal cancer screening, so we need to pay more attention to the establishment of guidelines with high quality and high credibility for colorectal cancer screening as well as for cancer screening based on the national condition, in order to provide reasonable guidance for practice in public health and improve the health conditions in our society.

A Novel Blood-Based Colorectal Cancer Diagnostic Technology Using Electrical Detection of Colon Cancer Secreted Protein-2

Colorectal cancer (CRC) is the second-leading cause of cancer-related mortality worldwide, which may be effectively reduced by early screening. Colon cancer secreted protein-2 (CCSP-2) is a promising blood marker for CRC. An electric-field effect colorectal sensor (E-FECS), an ion-sensitive field-effect transistor under dual gate operation with nanostructure is developed, to quantify CCSP-2 directly from patient blood samples. The sensing performance of the E-FECS is verified in 7 controls and 7 CRC samples, and it is clinically validated on 30 controls, 30 advanced adenomas, and 81 CRC cases. The concentration of CCSP-2 is significantly higher in plasma samples from CRC and advanced adenoma compared with controls (both P < 0.001). Sensitivity and specificity for CRC versus controls are 44.4% and 86.7%, respectively (AUC of 0.67), and 43.3% and 86.7%, respectively, for advanced adenomas (AUC of 0.67). CCSP-2 detects a greater number of CRC cases than carcinoembryonic antigen does (45.6% vs 24.1%), and the combination of the two markers detects an even greater number of cases (53.2%). The E-FECS system successfully detects CCSP-2 in a wide range of samples including early stage cancers and advanced adenoma. CCSP-2 has potential for use as a blood-based biomarker for CRC.

Bowel preparation for colonoscopy may decrease the levels of testosterone in Korean men

Although colonoscopy is commonly conducted for medical check-ups in Korea, investigations for the influence of bowel preparation on various health conditions are insufficient. This cross-sectional study investigated whether bowel preparation has an influence on serum levels of testosterone. A total of 1114 men were divided into the bowel preparation group and control groups. The median total and free testosterone levels were significantly lower in the bowel preparation group (14.89 and 0.26 nmol/L, respectively) than in the control groups (15.72 and 0.28 nmol/L, respectively). The level of total testosterone significantly increased with age in the bowel preparation group (r = 0.103). The differences in the levels of total and free testosterone between the 2 groups were more prominent in younger men than in older men. In multivariate regression models, bowel preparation was independently associated with the levels of total and free testosterone. In these models, the interaction between age and bowel preparation was significant for the levels of total and free testosterone. In conclusion, bowel preparation may independently decrease the serum levels of total and free testosterone. The decline in testosterone was more evident in younger men than in older men.

Appropriate Surveillance Interval after Colonoscopic Polypectomy in Patients Younger than 50 Years

BACKGROUND

Current postpolypectomy surveillance guidelines are based on studies in patients aged ≥50 years. Equal application of the guidelines in patients aged < 50 years may be unreasonable. We aimed to determine an appropriate surveillance interval after adenoma removal in patients aged < 50 years.

METHODS

We studied 10,013 patients who underwent ≥ 1 adenoma removal and follow-up colonoscopy. The cumulative risk of metachronous advanced colorectal neoplasia (ACRN) was compared among the eight groups based on age (30-39, 40-44, 45-49 and ≥ 50 years) and baseline adenoma characteristics (low- [LRA] and high-risk adenoma [HRA]).

RESULTS

The risk of metachronous ACRN in patients aged 30-39 and 40-44 years with HRA was comparable to that in those aged ≥ 50 years with LRA (P = 0.839 and P = 0.381, respectively). However, the risk in those aged 45-49 years with HRA was higher than in those aged ≥ 50 years with LRA (P = 0.003), and the risk was not significantly different from that in those aged ≥ 50 years with HRA (P = 0.092). Additionally, the 5-year cumulative risk in those aged 45-49 years with LRA was not significantly different from that in those aged ≥ 50 years with LRA.

CONCLUSION

The postpolypectomy surveillance interval can be extended up to 5 years in patients aged 30-44 years with HRA, similar to those aged ≥ 50 years with LRA. However, the interval in patients aged 45-49 years with HRA and LRA should be 3 and 5 years, respectively, similar to those aged ≥ 50 years.

A Comparative Study Evaluating the Incidence of Colorectal Neoplasia(s) in Candidates for Bariatric Surgery by Screening Colonoscopy, 40-49 Versus 50-65 Years Old: a Preliminary Study

INTRODUCTION

Obesity and metabolic syndrome (MetS) are associated with colorectal neoplasia (CRN) and carcinoma (CRC). Whether such subjects must undergo screening colonoscopy (SC) earlier, is unknown. Incidences of CRNs in 40-49- versus 50-65-year-old bariatric patients were compared by SC. No prospective data on SC is available in morbidly obese/MetS.

MATERIAL AND METHODS

Surgical weight loss candidates over 39 years of age, asymptomatic, and average-risk for CRC offered SC. Those giving written informed consent were enrolled. Colonoscopies were done by the same surgeon. Smoking/drinking history, fasting blood glucose (FBG), insulin, C-peptide, triglyceride, high density lipoprotein, vitamin D, HbA1c, and insulin resistance parameters were recorded. CRN rate and the distribution of variables in patients 40-49 years of age were compared with 50-65. Student's t and Chi-square tests were used as appropriate. P < 0.05 was regarded as statistically significant.

RESULTS

Among 168 SCs, 47 had CRNs (27.9%). Including carcinoma, 15 had an advanced CRN (aCRN) (8.9% aCRN and 0.6% CRC). CRN rate was 35.6% in ≥ 50 years old whereas 22.1% in 40-49 (p = 0.053). aCRN rates (8.4% in 40-49 versus 9.6% in 50-65) were similar (p = 0.792). Metabolic parameters and smoking-drinking history were equally distributed between the groups except FBG and HbA1c as their mean levels were slightly higher in the 50-65 age group (p < 0.05).

CONCLUSIONS

Presented results warrant routine SC in the 40-49-year-old morbidly obese and/or MetS patient population with average risk, and in aged > 50, it certainly must be enforced and included in the preoperative check-list if not done before.

Impact of family history of colorectal cancer on age-specific prevalence of colorectal neoplasia

BACKGROUND AND AIM

There are no established guidelines on screening strategies for persons with a family history of colorectal cancer (CRC) in Korea. We aimed to evaluate the age-specific risk of colorectal neoplasia according to family history of CRC.

METHODS

Participants who underwent screening colonoscopy were included. Age-specific prevalence of non-advanced adenoma (NAA) and advanced colorectal neoplasia (ACRN) was calculated according to family history of CRC.

RESULTS

Among 35 997 participants, 1339 (3.7%) had a family history of CRC in first-degree relatives. A family history of CRC was an independent risk factor for NAA (adjusted odds ratio [AOR] 1.33, 95% confidence interval [CI] 1.16-1.52). In the subgroup analysis by age, family history of CRC was a risk factor for NAA in the 50-59 and ≥ 60 years groups (AOR [95% CI]: 1.42 [1.04-1.91] and 2.33 [1.34-4.09], respectively), but not in the 30-39 and 40-49 years groups. In the curve of age-specific prevalence of NAA, the gap of the prevalence between the family history and non-family history groups began to widen after the mid-50s. In cases of ACRN, a family history of CRC was not a risk factor in the entire age group (AOR 1.16, 95% CI 0.75-1.70). In the curve of age-specific prevalence of ACRN, however, the gap of the prevalence between the family history and non-family history groups began to widen after the early 60s.

CONCLUSION

Although a family history of CRC is a risk factor for NAA, it may affect NAA development from the mid-50s and ACRN development from the early 60s.

Increasing Trend in Young-Onset Colorectal Cancer in Asia: More Cancers in Men and More Rectal Cancers

BACKGROUND

The incidence of young-onset colorectal cancer (CRC) is reported to be increasing in the Western world. There are no population-based studies assessing the trend across Asia.

METHODS

We performed a multinational cohort study involving four Asian countries/regions, namely Taiwan, Korea, Japan, and Hong Kong. The magnitude and direction of trend in the incidence of young-onset CRC (age < 50) were quantified using Joinpoint Regression Program to estimate average annual percentage change (AAPC).

RESULTS

In Taiwan (1995-2014), incidence of young-onset CRC significantly increased in both men (colon cancer: 4.9-9.7 per 100,000; rectal cancer: 4.0-8.3 per 100,000) and women (colon cancer: 5.1-9.7 per 100,000; rectal cancer: 3.8-6.4 per 100,000). In Korea (1999-2014), incidence of young-onset CRC significantly increased in both men (colon cancer: 5.0-10.4 per 100,000; rectal cancer: 4.9-14.0 per 100,000) and women (colon cancer: 4.1-9.6 per 100,000; rectal cancer: 4.1-9.1 per 100,000). The most pronounced change was observed with male rectal cancer, increasing by 3.9% per year in Taiwan (AAPC + 3.9, 95% confidence interval + 3.3 to +4.5, P < 0.05) and 6.0% per year in Korea (AAPC +6.0, 95% confidence interval + 4.5 to +7.6, P < 0.05). Only a significant increase in rectal cancer was noted in Japan (male rectal cancer: 7.2-10.1 per 100,000, female rectal cancer 4.7-6.7 per 100,000) and Hong Kong (male rectal cancer: 4.4-7.0 per 100,000).

CONCLUSIONS

Increasing trend in young-onset CRC is not limited to the Western world. This finding may have implications on screening program for CRC in these countries/regions.

Prevalence of and Risk Factors for Colorectal Neoplasia in Asymptomatic Young Adults (20-39 Years Old)

BACKGROUND & AIMS

The incidence of colorectal cancer is increasing among persons 50 years old or younger. However, data on the epidemiology of young-onset colorectal neoplasia (CRN) are limited. Although some studies have investigated the epidemiology of CRN in persons younger than 50 years, most have focused on persons 40 years or older. We evaluated the prevalence of and risk factors for CRN in adults younger than 40 years.

METHODS

We performed a cross-sectional analysis of 72,356 asymptomatic individuals, 20-39 years old, who underwent colonoscopies as participants in the Kangbuk Samsung Health Study in South Korea, from August 2004 through December 2015. Data on medical history and health-related behavior were collected from self-administered questionnaires. Patients were divided into groups based on age (20-29 years, n = 7340 or 30-39 years, n = 65,016), and χ² tests were used to compare categorical variables between groups. A multivariate logistic regression model was used to assess the risk factors for overall and advanced CRN.

RESULTS

The prevalence of overall CRN in group of 20-29 years was 5.9% and in the group of 30-39 years was 9.5% (P < .001); prevalence values for advanced CRN were 0.6% and 0.9%, respectively (P = .005). In the group of 30-39 years, age, smoking, alcohol intake, obesity, and abdominal obesity were independent risk factors for overall and advanced CRN. Additionally, male sex and metabolic syndrome were independent risk factors for overall CRN, whereas regular exercise reduced risk of overall CRN. Even in the 20-29 years group, obesity, abdominal obesity, and increased levels of triglycerides were independent risk factors for overall and advanced CRN, whereas age, increased blood pressure, and increased fasting blood glucose level were independent risk factors for overall CRN.

CONCLUSION

In a retrospective analysis of 72,356 asymptomatic persons under 40 years of age evaluated by colonoscopy in Korea, we found modifiable factors, such as smoking, alcohol intake, obesity, and metabolic syndrome, to be significant risk factors for CRN-even in persons of 20-39 years old. Colorectal cancer screening strategies should consider these risk factors.

Guideline Adherence to Colonoscopic Surveillance Intervals after Polypectomy in Korea: Results from a Nationwide Survey

Background/Aims

People around the world are increasingly choosing to undergo colorectal cancer screening via colonoscopy. As a result, guideline adherence to postpolypectomy colonoscopy surveillance has drawn increasing attention. The present study was performed to assess recognition and adherence to guidelines among primary care physicians and gastroenterologists and to identify characteristics associated with compliance.

Methods

A nationwide sample of primary care physicians employed at cancer screening facilities and registered members of the Korean Society of Gastrointestinal Endoscopy were recruited. Participants were asked to complete a survey of six hypothetical clinical scenarios designed to assess their potential course of action in response to screening or follow-up colonoscopy results. Frequencies and odds ratios and 95% confidence intervals for guideline adherence were estimated.

Results

The proportions of doctors recommending shortened colonoscopy surveillance intervals for low- and high-risk adenomas were greater than 90% among primary physicians and were much lower among gastroenterologists. Guideline adherence was relatively good among groups of doctors who were young, had a specialty in gastroenterology, worked at tertiary hospitals, and cared for an appropriate number of patients.

Conclusions

The present study reveals a remaining discrepancy between practitioner recommendations and current guidelines for postpolypectomy surveillance. Several factors were shown to be related to guideline adherence, suggesting a need for appropriate control and continuing education or training programs among particular groups of practitioners.

Risk of developing metachronous advanced colorectal neoplasia after colonoscopic polypectomy in patients aged 30 to 39 and 40 to 49 years

BACKGROUND AND AIMS

Current guidelines define postpolypectomy surveillance intervals in patients aged ≥50 years. The risk of metachronous colorectal neoplasia (CRN) and the optimal postpolypectomy surveillance interval in patients aged <50 years remain unclear. We compared the risk of metachronous CRN in patients aged 30 to 39, 40 to 49, and ≥50 years.

METHODS

We studied patients who underwent ≥1 adenoma removal between 2010 and 2014 and follow-up colonoscopic surveillance until 2017.

RESULTS

Among 10,014 patients studied, 3242, 4606, and 2166 were 30 to 39, 40 to 49, and ≥50 years old, respectively. After high-risk adenoma removal, the 3-year risk of metachronous advanced CRN (ACRN) in patients aged 30 to 39 and 40 to 49 years was lower than in patients ≥50 years old (1.9% and 3.6% vs 8.1%, respectively; P < .001 and .008). After low-risk adenoma removal, the 5-year risk of metachronous ACRN in patients aged 30 to 39 and 40 to 49 years was lower than in patients ≥50 years old (2.8% and 3.3% vs 5.9%, respectively; P = .010 and .031). The risk of metachronous ACRN or ≥3 adenomas in patients aged 30 to 39 years was significantly lower than in patients aged 40 to 49 years. Age remained significantly associated with the risk of metachronous ACRN despite adjustments for potential confounders.

CONCLUSIONS

The risk of metachronous ACRN was lower in patients aged <50 years than in those aged ≥50 years; thus, the postpolypectomy surveillance interval may be extendable to >3 and 5 years in high-risk and low-risk adenoma groups, respectively, in patients aged <50 years.

The prognostic implications of primary tumor location on recurrence in early-stage colorectal cancer with no associated risk factors

PURPOSE

Recently, several reports have suggested that tumor location serves as a prognostic biomarker in advanced colorectal cancer. However, the prognostic implication of tumor location in patients with early-stage colorectal cancer remains unclear. This study was aimed to examine the prognostic implication of tumor location in patients with early-stage colorectal cancer.

METHODS

Patients with stage I and low-risk stage II colorectal cancer, treated with radical surgery in a hospital setting between May 2003 and September 2014, were retrospectively reviewed. Patients who underwent (neo) adjuvant chemotherapy and/or radiotherapy and whose microsatellite instability (MSI) status was lacked were excluded. Distal colon cancer was defined as tumors located from the splenic flexure colon to the sigmoid colon.

RESULTS

A total of 712 patients were included in this study. Of these patients, 23 (3.2%) had a recurrence at a median follow-up time of 46 months. The tumor recurrence rate was significantly low in patients with proximal colon cancer. In the multivariate analysis, tumors located in the distal colon or rectum (distal colon, hazard ratio [HR] 9.213, P = 0.035; rectum, HR 15.366, P = 0.009) and T3 tumors (HR 4.590, P = 0.017) were related to tumor recurrence. A higher prevalence of tumor recurrence was found in patients with two recurrence factors than those who had only one factor or none (P < 0.001).

CONCLUSIONS

Tumor location, as well as T stage, had prognostic implication in patients with early-stage colorectal cancer. Validation of our results is needed in a large cohort with genetic characterization.

Advanced Colonic Neoplasia at Follow-up Colonoscopy According to Risk Components and Adenoma Location at Index Colonoscopy: A Retrospective Study of 1,974 Asymptomatic Koreans

Background/Aims

We aimed to estimate the cumulative incidence of advanced colonic neoplasia and analyze the risk factors for advanced colonic neoplasia according to risk components and adenoma location at index colonoscopy.

Methods

We reviewed 1,974 subjects who underwent a follow-up colonoscopy after a complete screening colonoscopy and the removal of all polyps. We estimated the cumulative incidence of a subsequent advanced neoplasia according to risk groups (normal, low-risk, and high-risk). Risk factors were analyzed by risk components (≥3 adenomas, adenoma ≥1 cm, and villous-type adenoma) and adenoma location.

Results

Overall, 111 advanced neoplasias (5.6%) were newly diagnosed at the follow-up colonoscopy. The 3-year cumulative incidences of advanced neoplasia were 0.8%, 3.1%, and 10.2% in the normal, low-risk, and high-risk groups, respectively (p<0.0001), and the 5-year cumulative incidences were 2.2%, 8.6%, and 20.2%, respectively (p<0.0001). Age ≥60 years (hazard ratio [HR], 1.78; 95% confidence interval [CI], 1.21 to 2.63), right-sided colonic adenoma (HR, 1.74; 95% CI, 1.13 to 2.66), ≥3 adenomas (HR, 2.00; 95% CI, 1.22 to 3.28), and adenomas ≥1 cm in size (HR, 2.03; 95% CI, 1.20 to 3.44) in the index colonoscopy were independent risk factors for subsequent development of advanced neoplasia.

Conclusions

Right-sided colonic adenoma, ≥3 adenomas, adenomas ≥1 cm, and age ≥60 years at the index colonoscopy were significant risk factors for advanced neoplasia following a complete screening colonoscopy and removal of all polyps.

A combination of clinical risk stratification and fecal immunochemical test is useful for identifying persons with high priority of early colonoscopy

BACKGROUND

We aimed to develop a combination screening strategy for advanced colorectal neoplasia based on the Asia-Pacific Colorectal Screening score and fecal immunochemical test results.

METHODS

We reviewed the records of participants who had undergone a colonoscopy and fecal immunochemical test as part of a comprehensive health screening program. The prevalence of advanced colorectal neoplasia in participants 40-49 years old was analyzed according to Asia-Pacific Colorectal Screening scores and fecal immunochemical test results.

RESULTS

We analyzed the data of 9205 participants 40-49 years old and 3215 participants ≥50 years old. The prevalence of advanced colorectal neoplasia in participants 40-49 years old was 1.0%, 2.1%, 7.1%, and 13.4% in the "fecal immunochemical test (-) & Asia-Pacific Colorectal Screening<2," "fecal immunochemical test (-) & Asia-Pacific Colorectal Screening≥2," "fecal immunochemical test (+) & Asia-Pacific Colorectal Screening<2," and "fecal immunochemical test (+) & Asia-Pacific Colorectal Screening≥2" subgroups, respectively. The prevalence of advanced colorectal neoplasia in "fecal immunochemical test (+) & Asia-Pacific Colorectal Screening≥2" subgroup was higher than in participants ≥50 years old with Asia-Pacific Colorectal Screening≥4 (13.4% vs. 5.8%, P<0.001).

CONCLUSIONS

Fecal immunochemical test-positive individuals 40-49 years old with an Asia-Pacific Colorectal Screening≥2 have a higher risk of advanced colorectal neoplasia than individuals ≥50 years old with an Asia-Pacific Colorectal Screening≥4.

Risk of metachronous neoplasia on surveillance colonoscopy in young patients with colorectal neoplasia

BACKGROUND AND AIMS

Few prior reports exist that address the appropriate colonoscopy surveillance interval for individuals <50 years old. We compared the risk of metachronous neoplasia between younger (20-49 years) and older (50-54 years) cohorts.

METHODS

This multicenter retrospective cohort study compared the incidence of metachronous neoplasia in younger and older cohorts according to baseline risk stratification. Subjects were eligible if they underwent their first colonoscopy between June 2006 and May 2010 and had at least 1 or more surveillance colonoscopy up to June 2015.

RESULTS

Among a total of 10,477 subjects who underwent baseline colonoscopy, 9722 were eligible after excluding 755 subjects. Of those 9722 subjects, 43% underwent surveillance colonoscopy. In the baseline high-risk adenoma group (n = 840), the 3-year risk of metachronous advanced neoplasia was 10.7% in the younger patients on screening colonoscopy and 8.9% in the older patients (P > .1). In the baseline low-risk adenoma group (n = 1869), the 5-year risk of metachronous advanced neoplasia was 4.9% in the younger patients on screening colonoscopy and 5.1% in the older patients (P > .1). Similarly, in the baseline no neoplasia group (n = 7013), the 5-year risk of metachronous advanced neoplasia was 4.1% in the younger patients on screening colonoscopy and 5.6% in the older patients (P > .1).

CONCLUSIONS

Considering the similar risk of metachronous advanced neoplasia in younger and older individuals, we suggest a 3-year surveillance interval for high-risk adenoma and a 5-year surveillance interval for low-risk adenoma in young individuals without a strong family history.

Optimal colonoscopy surveillance interval period for the adenoma patients who had an adequate polypectomy at baseline colonoscopy

The role of surveillance colonoscopy has long been established: it reduces both the incidence and the mortality of colorectal cancer. We aimed to assess the optimal colonoscopy surveillance interval period for the adenoma patients who underwent an adequate polypectomy at baseline colonoscopy to avoid overuse or underuse of colonoscopy. A retrospective study was carried out on the baseline adenoma patients who had had at least two completed colonoscopy examinations during the years 2000-2013 in the Digestive Endoscopy Center of the First Affiliated Hospital of Kunming Medical University. All the patients had a complete polypectomy of adenomas at baseline. Data on the patients' demographics and colorectal findings were extracted from a specially designed colonoscopy database. The end point was the finding of adenoma during the subsequent surveillance colonoscopy; an analysis was carried out to identify recurrence factors and the optimal colonoscopy surveillance interval period. A total of 765 (463 men, 302 women, average age 56.51±11.95) eligible patients were included in the study. Three hundred and twelve patients had adenoma and 453 had no adenoma after surveillance colonoscopies (the frequency of repeat colonoscopy is 1-10, average 1.73±1.24). The diameter of adenomas found on the follow-up colonoscopy was 0.2-3.0 cm (average 0.54±0.30 cm). The number of adenomas was 1-11 (2.21±1.53) and the surveillance adenoma interval period was 0.5-13 years (2.64±2.36 years). A total of 576 patients had baseline nonadvanced adenomas. Male sex, age older than 50 years, and more than two different intestine segment adenomas were the risk factors for recurrence. The optimal colonoscopy surveillance interval period is 2.85 years (95% confidence interval: 2.53-3.17) according to the recurrence rate of 5% adenomas. One hundred and eighty-nine patients had baseline advanced adenomas. Male sex, diameter of adenomas less than 1.0 cm, and adenomas in the right colon or the whole colon were the risk factors for recurrence. The optimal colonoscopy surveillance interval period is 2.06 years (95% confidence interval: 1.71-2.45) according to the recurrence rate of 5% adenomas. The optimal colonoscopy surveillance interval period is 3 years or so for the adenoma patients who had an adequate polypectomy at baseline colonoscopy. Male sex, age older than 50 years, less than 1.0 cm adenomas diameter and the right colon, or multisegment intestine adenomas were the risk factors for recurrence. This has significance for guiding the follow-up colonoscopy interval time of the patients with intestine adenomas.

Systematic review of colorectal cancer screening guidelines for average-risk adults: Summarizing the current global recommendations

AIM

To summarize and compare worldwide colorectal cancer (CRC) screening recommendations in order to identify similarities and disparities.

METHODS

A systematic literature search was performed using MEDLINE, EMBASE, Scopus, CENTRAL and ISI Web of knowledge identifying all average-risk CRC screening guideline publications within the last ten years and/or position statements published in the last 2 years. In addition, a hand-search of the webpages of National Gastroenterology Society websites, the National Guideline Clearinghouse, the BMJ Clinical Evidence website, Google and Google Scholar was performed.

RESULTS

Fifteen guidelines were identified. Six guidelines were published in North America, four in Europe, four in Asia and one from the World Gastroenterology Organization. The majority of guidelines recommend screening average-risk individuals between ages 50 and 75 using colonoscopy (every 10 years), or flexible sigmoidoscopy (FS, every 5 years) or fecal occult blood test (FOBT, mainly the Fecal Immunochemical Test, annually or biennially). Disparities throughout the different guidelines are found relating to the use of colonoscopy, rank order between test, screening intervals and optimal age ranges for screening.

CONCLUSION

Average risk individuals between 50 and 75 years should undergo CRC screening. Recommendations for optimal surveillance intervals, preferred tests/test cascade as well as the optimal timing when to start and stop screening differ regionally and should be considered for clinical decision making. Furthermore, local resource availability and patient preferences are important to increase CRC screening uptake, as any screening is better than none.

Anatomical distribution and detection rate of colorectal neoplasms according to age in the colonoscopic screening of a Korean population

Purpose

Because data as a basis for the determination of proper age and modality for screening of colorectal neoplasms is lacking, we evaluated detection rates and anatomical distribution of colorectal neoplasms according to age in healthy individuals who underwent total colonoscopy for health checkup.

Methods

A total of 16,100 cases that had received the colonoscopic examination from January to December in 2014 were analyzed. The total number of individuals who received total colonoscopy were divided by the number of individuals harboring colorectal adenoma to calculate the detection rate of colorectal adenoma. Individuals ≤50 years old were classified as young-age group and aged >50 were old-age group. Differences in anatomical locations of colorectal neoplasms were analyzed in the 2 age groups by chi-square test. Risk factors for colorectal adenoma in each age group were analyzed using univariate and multivariate logistic regression analyses.

Results

Detection rates of colorectal adenoma were 13.7% in all cases and 12.8% for those in their 40's. The main anatomical location of colorectal adenoma was proximal colon in both age groups (P < 0.001). Hyperplastic polyp was mainly distributed to the distal colon in both age groups (P < 0.001). Distal colon was the major site for colorectal cancer in the old-age group (P = 0.001). Proximal location of neoplasms was a risk factor for colorectal adenoma in both age groups with multivariate analysis.

Conclusion

These data could be the bases for earlier initiation of screening for colorectal neoplasms with total colonoscopy to detect clinically significant colorectal polyps.

Colorectal cancer screening with the fecal immunochemical test in persons aged 30 to 49 years: focusing on the age for commencing screening

BACKGROUND AND AIMS

The fecal immunochemical test (FIT) can be an alternative screening method for colorectal cancer in individuals aged <50 years. However, debate continues concerning the age at which commencing FIT is beneficial.

METHODS

We reviewed the records of participants who had undergone a colonoscopy and FIT as part of a comprehensive health screening program. To determine the age for commencing screening via FIT, participants aged <50 years were classified into 4 age subgroups as follows: 30 to 34, 35 to 39, 40 to 44, and 45 to 49 years. Average-risk participants aged 50 to 59 years comprised the control group.

RESULTS

We analyzed the data of 19,808 participants aged 30 to 49 years and 2233 average-risk participants aged 50 to 59 years. The advanced colorectal neoplasia (ACRN) prevalence in average-risk participants aged 50 to 59 years was 3.8%. In the subgroups of FIT-positive participants, the proportion of participants with ACRN was 2.9% (95% confidence interval [CI], 1.1%-7.4%), 9.7% (95% CI, 5.8%-15.6%), 7.7% (95% CI, 4.5%-12.8%), and 14.6% (95% CI, 8.7%-23.5%) in groups 30 to 34, 35 to 39, 40 to 44, and 45 to 49 years, respectively. The proportion of FIT-positive participants with ACRN in the groups aged 35 to 39, 40 to 44, and 45 to 49 years was higher than that in average-risk participants aged 50 to 59 years (P = .001, P = .014, and P < .001, respectively), whereas that in FIT-positive participants aged 30 to 34 years was not (P = .566).

CONCLUSION

FIT-positive individuals aged 35 to 49 years had a higher risk of ACRN compared with average-risk individuals aged 50 to 59 years. FIT-positive individuals aged 35 to 49 years may benefit from screening colonoscopy, thus justifying the possibility of commencing FIT from age 35 years.

Screening of colorectal cancer: present and future

INTRODUCTION

Colorectal cancer (CRC) is the third most common cancer in males and second in females, and the fourth most common cause of cancer death worldwide. Currently, about 60-70% of diagnosed cases in symptomatic patients are detected at an advanced stage of disease. Earlier stage detection through the use of screening strategies would allow for better outcomes in terms of reducing the disease burden. Areas covered: The aim of this paper is to review the current published evidence from literature which assesses the performance and effectiveness of different screening tests for the early detection of CRC. Expert commentary: Adequate screening strategies can reduce CRC incidence and mortality. In the last few decades, several tests have been proposed for CRC screening. To date, there is still insufficient evidence to identify which approach is definitively superior, and no screening strategy for CRC can therefore be defined as universally ideal. The best strategy would be the one that can be economically viable and to which the patient can adhere best to over time. The latest guidelines suggest colonoscopy every 10 years or annual fecal immuno-chemical test (FIT) for people with normal risk, while for individuals with high risk or hereditary syndromes specific recommendations are provided.

Impact of Age on the Risk of Advanced Colorectal Neoplasia in a Young Population: An Analysis Using the Predicted Probability Model

BACKGROUND

The incidence of colorectal cancer is decreasing in adults aged ≥50 years and increasing in those aged <50 years.

AIMS

We aimed to establish risk stratification model for advanced colorectal neoplasia (ACRN) in persons aged <50 years.

METHODS

We reviewed the records of participants who had undergone a colonoscopy as part of a health examination at two large medical examination centers in Korea. By using logistic regression analysis, we developed predicted probability models for ACRN in a population aged 30-49 years.

RESULTS

Of 96,235 participants, 57,635 and 38,600 were included in the derivation and validation cohorts, respectively. The predicted probability model considered age, sex, body mass index, family history of colorectal cancer, and smoking habits, as follows: Y _ACRN = -8.755 + 0.080·X _age - 0.055·X _male + 0.041·X _BMI + 0.200·X _{family_history_of_CRC} + 0.218·X _{former_smoker} + 0.644·X _{current_smoker}. The optimal cutoff value for the predicted probability of ACRN by Youden index was 1.14%. The area under the receiver-operating characteristic curve (AUROC) values of our model for ACRN were higher than those of the previously established Asia-Pacific Colorectal Screening (APCS), Korean Colorectal Screening (KCS), and Kaminski's scoring models [AUROC (95% confidence interval): model in the current study, 0.673 (0.648-0.697); vs. APCS, 0.588 (0.564-0.611), P < 0.001; vs. KCS, 0.602 (0.576-0.627), P < 0.001; and vs. Kaminski's model, 0.586 (0.560-0.612), P < 0.001].

CONCLUSION

In a young population, a predicted probability model can assess the risk of ACRN more accurately than existing models, including the APCS, KCS, and Kaminski's scoring models.

Training in Endoscopy: Colonoscopy

Colonoscopy is effective in reducing the morbidity and mortality associated with colorectal cancer (CRC). Interval cancers or post-colonoscopy CRCs, are cancers detected within the surveillance interval, or between 6–36 months after a clearing colonoscopy. The incidence of interval cancers is 3.4%–9.2% of all detected CRCs, as reported in population-based studies. Colonoscopy is a technically difficult procedure that is challenging to learn, and needs time and effort to gain competency. Therefore, trainee competence is a critical component of CRC screening and surveillance. Herein, we review the colonoscopy training methods and quality assessment metrics for colonoscopy competency.

Biomedical optical spectroscopy for the early diagnosis of gastrointestinal neoplasms

Gastrointestinal cancer is a leading contributor to cancer-related morbidity and mortality worldwide. Early diagnosis currently plays a key role in the prognosis of patients with gastrointestinal cancer. Despite the advances in endoscopy over the last decades, missing lesions, undersampling and incorrect sampling in biopsies, as well as invasion still result in a poor diagnostic rate of early gastrointestinal cancers. Accordingly, there is a pressing need to develop non-invasive methods for the early detection of gastrointestinal cancers. Biomedical optical spectroscopy, including infrared spectroscopy, Raman spectroscopy, diffuse scattering spectroscopy and autofluorescence, is capable of providing structural and chemical information about biological specimens with the advantages of non-destruction, non-invasion and reagent-free and waste-free analysis and has thus been widely investigated for the diagnosis of oesophageal, gastric and colorectal cancers. This review will introduce the advances of biomedical optical spectroscopy techniques, highlight their applications for the early detection of gastrointestinal cancers and discuss their limitations.

Stages of Adoption for Fecal Occult Blood Test and Colonoscopy Tests for Colorectal Cancer Screening in Korea

Purpose

While colorectal cancer (CRC) is common in Asian countries, screening for CRC is not. Moreover, CRC screening behaviors in Asian populations remain largely unknown. The present study aimed to investigate the stages of adopting CRC screening in Korea according to screening modality.

Materials and Methods

Data were obtained from the 2014 Korean National Cancer Screening Survey, a cross-sectional survey that utilized nationally representative random sampling to investigate cancer screening rates. A total of 2,066 participants aged 50-74 years were included in this study. Chi-square test and multinomial logistic regressionwere applied to determine stages of adoption for fecal occult blood test (FOBT) and colonoscopy and factors associated with each stage.

Results

Of 1,593 participants included in an analysis of stage of adoption for FOBT, 36% were in action/maintenance stages, while 18%, 40%, and 6% were in precontemplation, contemplation, and relapse/relapse risk stages, respectively. Of 1,371 subjects included in an analysis of stage of adoption for colonoscopy, 48% were in action/maintenance stages, with 21% in precontemplation, 21% in contemplation, and 11% in relapse/relapse risk stages. Multinomial logistic regression highlighted sex, household income, place of residency, family history of cancer, having private cancer insurance, smoking status, alcohol use, and regular exercise as being associated with stages of adoption for FOBT and colonoscopy.

Conclusion

This study outlines the distributions of stages of adoption for CRC screening by screening modality. Interventions to improve screening rates should be tailored to individuals in particular stages of adoption for CRC screening by modality.

The fecal immunochemical test has high accuracy for detecting advanced colorectal neoplasia before age 50

BACKGROUND

In contrast to the decreasing incidence of colorectal cancer (CRC) in adults ≥50 years, the CRC incidence in young adults <50 years is increasing. The fecal immunochemical test (FIT) may be useful for advanced colorectal neoplasia (ACRN) screening in a young population.

AIMS

To evaluate the diagnostic accuracy of FIT in a young population.

METHODS

The diagnostic performance of FIT for detecting ACRN was compared among the following age groups who underwent FIT and colonoscopy as part of a comprehensive health screening program: 30-39, 40-49, and ≥50 years.

RESULTS

Of 26,316 participants, 464 (1.8%) had ACRN and 805 (3.1%) showed positive FIT results. No significant differences in the sensitivity (22.1%, 17.2%, and 22.0%; p=0.435) and specificity (97.2%, 97.4%, and 96.9%; p=0.344) of FIT for detecting ACRN were observed among the groups. However, 30-39 age group had a significantly higher accuracy of FIT for ACRN (96.7%) than 40-49 and ≥50 age groups (95.9% and 93.8%; p<0.001). The areas under the receiver operating characteristic curves of FIT for ACRN of three age groups were not significantly different (67.2, 66.2, and 61.7; p=0.952).

CONCLUSIONS

The diagnostic performance of FIT for ACRN in a young population (<50 years) was not inferior to that in the current screening-age population (≥50 years). The FIT may be a good choice for detecting ACRN in a young population.

A simple scoring model for advanced colorectal neoplasm in asymptomatic subjects aged 40-49 years

Background

Limited data are available for advanced colorectal neoplasm in asymptomatic individuals aged 40–49 years. We aimed to identify risk factors and develop a simple prediction model for advanced colorectal neoplasm in these persons.

Methods

Clinical data were collected on 2781 asymptomatic subjects aged 40–49 years who underwent colonoscopy for routine health examination. Subjects were randomly allocated to a development or validation set. Logistic regression analysis was used to determine predictors of advanced colorectal neoplasm.

Results

The prevalence of overall and advanced colorectal neoplasm was 20.2 and 2.5% respectively. Older age (45–49 years), male sex, positive serology of Helicobacter pylori, and high triglyceride and low high-density lipoprotein (HDL) levels were independently associated with an increased risk of advanced colorectal neoplasm. BMI (body mass index) was not significant in multivariable analysis. We developed a simple scoring model for advanced colorectal neoplasm (range 0–9). A cutoff of ≥4 defined 43% of subjects as high risk for advanced colorectal neoplasm (sensitivity, 79%; specificity, 58%; area under the receiver operating curve = 0.72) in the validation datasets.

Conclusion

Older age (45–49 years), male sex, positive serology of H. pylori, high triglyceride level, and low HDL level were identified as independent risk factors for advanced colorectal neoplasm.

Effect of Previous Gastrectomy on the Performance of Postoperative Colonoscopy

Purpose

The purpose of this study was to determine the effect of a prior gastrectomy on the difficulty of subsequent colonoscopy, and to identify the surgical factors related to difficult colonoscopies.

Materials and Methods

Patients with a prior gastrectomy who had undergone a colonoscopy between 2011 and 2014 (n=482) were matched (1:6) to patients with no history of gastrectomy (n=2,892). Cecal insertion time, intubation failure, and bowel clearance score were compared between the gastrectomy and control groups, as was a newly generated comprehensive parameter for a difficult/incomplete colonoscopy (cecal intubation failure, cecal insertion time >12.9 minutes, or very poor bowel preparation scale). Surgical factors including surgical approach, extent of gastrectomy, extent of lymph node dissection, and reconstruction type, were analyzed to identify risk factors for colonoscopy performance.

Results

A history of gastrectomy was associated with prolonged cecal insertion time (8.7±6.4 vs. 9.7±6.5 minutes; P=0.002), an increased intubation failure rate (0.1% vs. 1.9%; P<0.001), and a poor bowel preparation rate (24.7 vs. 29.0; P=0.047). Age and total gastrectomy (vs. partial gastrectomy) were found to be independent risk factors for increased insertion time, which slowly increased throughout the postoperative duration (0.35 min/yr). Total gastrectomy was the only independent risk factor for the comprehensive parameter of difficult/incomplete colonoscopy.

Conclusions

History of gastrectomy is related to difficult/incomplete colonoscopy performance, especially in cases of total gastrectomy. In any case, it may be that a pre-operative colonoscopy is desirable in selected patients scheduled for gastrectomy; however, it should be performed by an expert endoscopist each time.