Colorectal cancer screening by colonoscopy: putting it into perspective

Clinical value of sigmoid colon water exchange colonoscopy: a prospective randomized clinical trial

This prospective randomized controlled trial investigated the clinical value of sigmoid colon water exchange (SWE) colonoscopy by comparing it with air insufflation (AI) colonoscopy in terms of the patient's pain score, insertion time, and screening quality. Consecutive patients who underwent colonoscopy without sedation were randomized into an AI group (n = 267) or an SWE group (n = 255). Patient characteristics, history of abdominal or pelvic surgery, maximum pain score, insertion time, cecal intubation rate, polyp detection rate, and the need for maneuvers were recorded. There was no significant between-group difference in insertion time, cecal intubation rate, assisted maneuvers (abdominal pressure, changing patients' position), or polyp detection rate (P > 0.05). The mean maximum pain score was significantly lower in the SWE group than in the AI group. (3.57 ± 2.01 vs. 4.69 ± 1.83, P < 0.001). For patients with a history of abdominal or pelvic surgery and those who were overweight (body mass index > 24), the maximum pain scores were lower in the SWE group than in the AI group (3.67 ± 1.95 vs. 4.88 ± 1.80, P < 0.001; 3.40 ± 1.96 vs. 4.79 ± 1.97, P < 0.001, respectively). SWE colonoscopy can significantly reduce abdominal pain with non-inferior screening quality and does not increase insertion time.Trial registration number: ChiCTR2200059057 (date April 23, 2022).

Karyopherin Subunit Alpha 1 Enhances the Malignant Behaviors of Colon Cancer Cells via Promoting Nuclear Factor-κB p65 Nuclear Translocation

BACKGROUND/AIMS

Aberrant nuclear factor-κB p65 (NF-κB p65) nuclear import commonly occurs in multiple cancers, including colon cancer. According to BioGRID, we noted that Karyopherin subunit alpha 1 (KPNA1), an important molecular transporter between the nucleus and the cytoplasm, may interact with NF-κB p65. KPNA1 itself is highly expressed in colon adenocarcinoma samples (N = 286) based on The Cancer Genome Atlas (TCGA) database. We aimed to explore the role of KPNA1 in colonic carcinogenesis and to determine whether NF-κB p65 nuclear translocation was involved.

METHODS

KPNA1 expressions at mRNA and protein levels were analyzed in colon cancer tissues. The regulatory effect of KPNA1 on malignant biological properties was detected in SW480 and HCT116 colon cancer cells. Coimmunoprecipitation and immunofluorescence were performed to verify the relationship between KPNA1 and NF-κB p65. KPNA1 ubiquitination was also preliminarily investigated.

RESULTS

KPNA1 was firstly confirmed as a significantly upregulated gene in our collected clinical colon cancer samples (N = 35). KPNA1 depletion inhibited cell proliferation, induced cell cycle arrest, and diminished migratory and invasive capacity of SW480 and HCT116 cells. Colon cancer cells overexpressing KPNA1 acquired more aggressive behaviors. KPNA1 acted as a transporter to induce the nuclear accumulation of NF-κB p65, thereby activating NF-κB signaling pathway in colon cancer cells. Furthermore, HECT, C2, and WW Domain-Containing E3 Ubiquitin (HECW2) interacted with KPNA1 to induce its ubiquitination. KPNA1 labeled with polyubiquitins was degraded through ubiquitin-proteasome system.

CONCLUSION

The present study uncovers a role of KPNA1-NF-κB p65 axis in promoting colonic carcinogenesis.

Cost-effectiveness analysis of different screening strategies for colorectal cancer in Guangzhou, southern China: a Markov simulation analysis based on natural community screening results

OBJECTIVES

To evaluate the cost-effectiveness of four different primary screening strategies: high-risk factor questionnaire (HRFQ) alone, single immunochemical faecal occult blood test (iFOBT), double iFOBT and HRFQ+double iFOBT for colorectal cancer (CRC) screening compared with no screening using the Markov model.

METHODS

Treeage Pro V.2011 software was used to simulate the Markov model. The incremental cost-effectiveness ratio, which was compared with the willingness-to-pay (WTP) threshold, was used to reflect the cost-effectiveness of the CRC screening method. One-way sensitivity analysis and probabilistic sensitivity analysis were used for parameter uncertainty.

RESULTS

All strategies had greater effectiveness because they had more quality-adjusted life years (QALYs) than no screening. When the WTP was ¥435 762/QALY, all screening strategies were cost-effective compared with no screening. The double iFOBT strategy was the best-buy option compared with all other strategies because it had the most QALYs and the least cost. One-way sensitivity analysis showed that the sensitivity of low-risk adenoma, compliance with colonoscopy and primary screening cost were the main influencing factors comparing single iFOBT, double iFOBT and HRFQ+double iFOBT with no screening. However, within the scope of this study, there was no fundamental impact on cost-effectiveness. Probabilistic sensitivity analysis showed that when the WTP was ¥435 762/QALY, the probabilities of the cost-effectiveness acceptability curve with HRFQ alone, single iFOBT, double iFOBT and HRFQ+double iFOBT were 0.0%, 5.3%, 69.3% and 25.4%, respectively.

CONCLUSIONS

All screening strategies for CRC were cost-effective compared with no screening strategy. Double iFOBT was the best-buy option compared with all other strategies. The significant influencing factors were the sensitivity of low-risk polyps, compliance with colonoscopy and cost of primary screening.

Real-World National Colonoscopy Volume in Korea: A Nationwide Population-Based Study over 12 Years

Background/Aims

Little is known about the national colonoscopy volume in Asian countries. This study aimed to assess the national colonoscopy volume in Korea over a 12-year period on the basis of a nationwide population-based database.

Methods

We conducted a population-based study for colonoscopy claims (14,511,158 colonoscopies performed on 13,219,781 patients) on the basis of the Korean National Health Insurance Service database from 2002 to 2013. The 12-year national colonoscopy burden was analyzed according to patient age, patient sex, and healthcare facility type.

Results

The overall volume of colonoscopy increased 8-fold over the 12-year period. The annual colonoscopic polypectomy rate significantly increased in all patient sex and age groups over the 12-years period (all p<0.001). The yearly colonoscopic polypectomy rate for men was significantly increased compared with that for women (2.3% vs 1.7%, p<0.001) and for the screening-age group compared with that for the young-age group (2.0% vs 1.6%, p<0.001). The yearly colonoscopic polypectomy rate relative to the total colonoscopy volume significantly increased in primary, secondary, and tertiary facilities by 2.4%, 1.9%, and 1.4% during the 12-year period (all p<0.001). In addition, the annual colonoscopy volume covered by high-volume facilities significantly increased by 1.8% in primary healthcare facilities over the 12-year period (p<0.001).

Conclusions

Healthcare resources should be prioritized to allow adequate colonoscopic capacity, especially for men, individuals in the screening-age group, and at primary healthcare facilities. Cost-effective strategies to improve the quality of colonoscopy may focus on primary healthcare facilities and high-volume facilities in Korea.

Intentions to undergo primary screening with colonoscopy under the National Cancer Screening Program in Korea

BACKGROUND

We sought to investigate intentions to undergo primary screening with colonoscopy in an attempt to predict future colorectal cancer screening behaviors and the feasibility of implementing colonoscopy as the primary screening modality for colorectal cancer in the National Cancer Screening Program (NCSP) of Korea.

METHODS

Data were obtained from a nationwide online survey conducted in 2018. The survey included a total of 800 eligible adults aged over 45 years. Study measures included the history of screening colonoscopy within the past 10 years and intentions to undergo primary screening with colonoscopy under the NCSP based on the five constructs of the Health Belief Model. Logistic regression analysis was conducted to examine factors associated with intentions to undergo primary screening with colonoscopy.

RESULTS

Approximately 77% of the participants expressed strong willingness to undergo primary screening with colonoscopy under the NCSP. Higher perceived severity and perceived benefits were significantly associated with stronger intentions to undergo screening with colonoscopy (adjusted odds ratio [aOR], 1.53; 95% confidence interval [CI], 1.10-2.14 and aOR, 2.74; 95% CI, 1.76-4.28, respectively). Greater perceived barriers (aOR, 0.65; 95% CI, 0.45-0.93) were significantly associated with weaker intentions. Cues to action elicited the strongest screening intentions (aOR, 8.28; 95% CI, 5.23-13.12).

CONCLUSION

The current study findings highlight the need for increasing awareness of the severity of CRC and the benefits of colonoscopy screening. Family-orientated recommendation strategies and reducing complications may boost an individual's intentions to undergo colonoscopy.

Effects of nurse-led interventions on early detection of cancer: A systematic review and meta-analysis

BACKGROUND

Early detection of cancer serves an important strategy for cancer control, but its uptake rate remains relatively limited. Nurse-led interventions may have potential benefits for the early detection of cancer, but the evidence remains unclear.

OBJECTIVES

Synthesise the evidence on the impact of nurse-led interventions on early cancer detection. The primary outcome was early cancer detection uptake rate. Secondary outcomes were cancer knowledge, early detection beliefs, diagnosed precancerous lesions and early-stage cancers.

DESIGN

A systematic review and meta-analysis of randomised controlled trails.

DATA SOURCES

Eight English language databases (British Nursing Index, Cochrane Central Register of Controlled Trials, CINAHL Complete, EMBASE, Ovid Emcare, Medline, Scopus, Web of Science Core Collection) and three Chinese language databases (Chinese Biomedical Literature Databases, China Journal Net, and Wanfang Data) were searched from inception date to September 2019. Grey literature and reference lists of included studies were also examined.

REVIEW METHODS

Two reviewers independently assessed eligibility, extracted data and evaluated methodological quality using the Cochrane risk of bias (RoB 2.0) tool. Meta-analyses and descriptive analyses were used. Subgroup analyses were conducted for study settings and intervention types.

RESULTS

Ten studies examined the effects of nurse-led interventions, including education, patient reminders, counselling, and patient navigation, on early detection of breast or cervical cancer, colorectal cancer, and lung cancer. Nurse-led interventions improved the uptake rates of mammography [risk ratio (RR) = 1.97; 95% confidence interval (CI): 1.17-3.33; p = 0.01], clinical breast examination (RR = 2.16; 95% CI: 1.02-4.59; p = 0.05), regular breast self-examination (RR = 2.01; 95% CI: 1.54-2.63; p < 0.001), and colonoscopy (RR = 1.90; 95% CI: 1.57-2.30; p < 0.001), but not of faecal blood occult tests. Subgroup analyses showed significantly improved mammography and clinical breast examination uptake rates for interventions conducted at health centres, and that patient navigation had better effects on improving colonoscopy uptake rates than did counselling. The intervention also improved cancer knowledge, early detection beliefs, and cases of detected precancerous lesions.

CONCLUSIONS

Nurse-led interventions may improve early cancer detection uptake rates, cancer knowledge, early detection beliefs, and cases of detected precancerous lesions. The effects of nurse-led interventions conducted in home settings on improving mammography and clinical breast examination uptake rates may need further exploration. Patient navigation may be superior to counselling in improving colonoscopy uptake rates. Social media may be an option for delivering early cancer detection guidance, but needs to be further explored. Tweetable abstract: Nurse-led interventions have potential effects on promoting early detection of cancer.

Histological grades of rectal cancer: whole-volume histogram analysis of apparent diffusion coefficient based on reduced field-of-view diffusion-weighted imaging

Background

To explore the role of whole-lesion histogram analysis of apparent diffusion coefficient (ADC) derived from reduced field-of-view (rFOV) diffusion-weighted imaging (DWI) technique in discriminating histological grades of rectal carcinoma.

Methods

Altogether, 49 patients with rectal cancer were enrolled in this retrospective study. All patients received preoperative 3.0 T MR scan. Histogram parameters from rFOV DWI were calculated and correlated with histological differentiation of rectal cancer. The parameters were compared between different histological grades of rectal cancer by independent Student's t-test or Man-Whitney U-test. The Spearman correlation test analyzed correlations between histological grade and histogram parameters. The diagnostic performance of individual parameters for distinguishing poorly from well-/moderately differentiated tumors was assessed by receiver operating characteristic curve (ROC) analysis.

Results

There were significant differences for ADCmean, 25^th, 50^th, 75^th, 90^th, 95^th percentiles, skewness, and kurtosis of rFOV DWI sequence between well-, moderately, and poorly differentiated rectal cancers (P<0.05). Significant correlations were noted between histological grades and the above histogram parameters (r=0.679, 0.540, 0.701, 0.730, 0.669, 0.574, -0.730, and -0.760 respectively, P<0.001). Among the individual histogram parameter, kurtosis achieved the highest AUC of 0.882 with an optimal cutoff value of 1.934 in distinguishing poorly from well-/moderately differentiated rectal cancers. The combination of ADCmean, 75^th percentile, and kurtosis yielded the highest AUC of 0.927 with a sensitivity of 88.00% and a sensitivity of 91.7% using logistic regression.

Conclusions

Quantitative whole-lesion ADC histogram analysis based on the rFOV DWI technique could help differentiate histological grades of rectal cancer. The combination of ADCmean, 75^th percentile, and kurtosis may be the best choice.

Circulating Extracellular Vesicle MicroRNA as Diagnostic Biomarkers in Early Colorectal Cancer-A Review

Colorectal cancer (CRC) is one of the most common malignancies in the developed world, with global deaths expected to double in the next decade. Disease stage at diagnosis is the single greatest prognostic indicator for long-term survival. Unfortunately, early stage CRC is often asymptomatic and diagnosis frequently occurs at an advanced stage, where long-term survival can be as low as 14%. Circulating microRNAs encapsulated in extracellular vesicles (EVs) have recently come to prominence as novel diagnostic markers for cancer. EV-miRNAs are dysregulated in the circulation of CRC patients compared to healthy controls, and several specific miRNA candidates have been posited as diagnostic markers, including miR-21, miR-23a, miR-1246, and miR-92a. This review outlines the current landscape of EV-miRNAs as potential diagnostic markers for CRC, with a specific focus on those able to detect early stage disease.

USP22 exerts tumor-suppressive functions in colorectal cancer by decreasing mTOR activity

USP22, the deubiquitinating subunit of the SAGA transcriptional cofactor complex, is a member of an 11-gene "death-from-cancer" signature. USP22 has been considered an attractive therapeutic target since high levels of its expression were associated with distant metastasis, poor survival, and high recurrence rates in a wide variety of solid tumors, including colorectal cancer (CRC). We sought to investigate the role of Usp22 during tumorigenesis in vivo using a mouse model for intestinal carcinogenesis with a tissue-specific Usp22 ablation. In addition, we assessed the effects of USP22 depletion in human CRC cells on tumorigenic potential and identified underlying molecular mechanisms. For the first time, we report that USP22 has an unexpected tumor-suppressive function in vivo. Intriguingly, intestine-specific Usp22 deletion exacerbated the tumor phenotype caused by Apc mutation, resulting in significantly decreased survival and higher intestinal tumor incidence. Accordingly, human CRC cells showed increased tumorigenic properties upon USP22 reduction in vitro and in vivo and induced gene expression signatures associated with an unfavorable outcome in CRC patients. Notably, USP22 loss resulted in increased mTOR activity with the tumorigenic properties elicited by the loss of USP22 being reversible by mTOR inhibitor treatment in vitro and in vivo. Here, we demonstrate that USP22 can exert tumor-suppressive functions in CRC where its loss increases CRC burden by modulating mTOR activity. Importantly, our data uncover a tumor- and context-specific role of USP22, suggesting that USP22 expression could serve as a marker for therapeutic stratification of cancer patients.

Willingness to pay for colorectal cancer screening in Guangzhou

AIM

To measure the willingness to pay for colorectal cancer screening in Guangzhou, and to identify those factors associated with it.

METHODS

A face-to-face questionnaire survey for pre-screening population from free and non-free colonoscopy districts was used to collect information on demographic characteristics, health behaviours, the intention of the cancer screenings and willingness to pay for colorectal cancer screening. A total of 1243 participants who took part in the pre-screening for colorectal cancer in Guangzhou were collected in the study. Categorical data were compared using the χ2 test to analyse significant differences. Non-conditional logistic regression and multi-class logistic regression were also performed for multivariate analysis and to estimate the odds ratios.

RESULTS

The percentage of participants willing to pay for colorectal cancer screening was 91.7%. "Unnecessary" was the dominant reason that participants gave for their unwillingness, accounting for 63.1%. Of those who were willing to pay, 29.2%, 20.7%, 14.8%, 13.0% and 22.4% of participants were willing to pay less than \100, \100-\199, \200-299, \300-\399 and more than \400, respectively. Non-logistic regression analysis showed that respondents who were male, had a high level of education, were from the family with more children/older to raise, and accepted colorectal cancer screening were willing to pay for this screening. Multi-class logistic regression analysis showed that respondents with higher annual household income per capita, from government and private enterprises, government agency/institution and peasants, and less family medical expenditure were willing to pay more.

CONCLUSION

Willingness to pay for colorectal cancer screening in Guangzhou is high, but the amount of willing to pay is not much.

The current capacity and quality of colonoscopy in Korea

Background/Aims

Little is known for the capacity and quality of colonoscopy, and adherence to colonoscopy surveillance guidelines in Korea. This study aimed to investigate the present and potential colonoscopic capacity, colonoscopic quality, and adherence to colonoscopy surveillance guidelines in Korea.

Methods

We surveyed representative endoscopists of 72 endoscopy units from June to August 2015, using a 36-item questionnaire regarding colonoscopic capacity, quality, and adherence to colonoscopy surveillance guidelines of each hospitals.

Results

Among the 62 respondents who answered the questionnaire, 51 respondents were analyzed after exclusion of 11 incomplete answers. Only 1 of 3 of endoscopy units can afford to perform additional colonoscopies in addition to current practice, and the potential maximum number of colonoscopies per week was only 42. The quality of colonoscopy was variable as reporting of quality indicators of colonoscopy were considerably variable (29.4%–94.1%) between endoscopy units. Furthermore, there are substantial gaps in the adherence to colonoscopy surveillance guidelines, as concordance rate for guideline recommendation was less than 50% in most scenarios.

Conclusions

The potential capacity and quality of colonoscopy in Korea was suboptimal. Considering suboptimal reporting of colonoscopic quality indicators and low adherence rate for colonoscopy surveillance guidelines, quality improvement of colonoscopy should be underlined in Korea.

Is water exchange superior to water immersion for colonoscopy? A systematic review and meta-analysis

Background/Aims

Recently, water exchange (WE) instead of water immersion (WI) for colonoscopy has been proposed to decrease pain and improve adenoma detection rate (ADR). This systematic review and meta-analysis is conducted to assess whether WE is superior to WI based on the published randomized controlled trials (RCTs).

Materials and Methods

We searched studies from PubMed, Cochrane Central Register of Controlled Trials, EMBASE, and MEDLINE. Only RCTs were eligible for our study. The pooled risk ratios (RRs), pooled mean difference (MD), and pooled 95% confidence intervals (CIs) were calculated by using the fixed-effects model or random-effects model based on heterogeneity.

Results

Five RCTs consisting of 2229 colonoscopies were included in this study. WE was associated with a significantly higher ADR than WI (RR = 1.18; CI = 1.05-1.32; P = 0.004), especially in right colon (RR = 1.31; CI = 1.07-1.61; P = 0.01). Compared with WI, WE was confirmed with lower pain score, higher Boston Bowel Preparation Scale score, but more infused water during insertion. There was no statistical difference between WE and WI in cecal intubation rate and the number of patients who had willingness to repeat the examination. Furthermore, both total procedure time and cecal intubation time in WE were significantly longer than that in WI (MD = 2.66; CI = 1.42-3.90; P < 0.0001; vs MD = 4.58; CI = 4.01-5.15; P < 0.0001).

Conclusions

This meta-analysis supports the hypothesis that WE is superior to WI in improving ADR, attenuating insertion pain and providing better bowel cleansing, but inferior in time and consumption of infused water consumption during insertion.

Patients' Preferences for Primary Colorectal Cancer Screening: A Survey of the National Colorectal Cancer Screening Program in Korea

Background/Aims

The adoption of colonoscopy as a primary colorectal cancer (CRC) screening technique has been argued for in Korea, without evidence of patient preferences. This study aimed to investigate patients’ preferences for the primary CRC screening test for the National Cancer Screening Program (NCSP).

Methods

Between June and August 2016, 414 individuals aged ≥50 years who participated in the NCSP were prospectively invited to complete a questionnaire regarding their preferences for the primary CRC screening test and the reasons for their selection.

Results

Among the 396 respondents who completed the questionnaire, 124 individuals (31.3%) preferred the fecal immunochemical test (FIT), whereas 272 individuals (68.7%) preferred colonoscopy. Elderly participants preferred the FIT (p<0.001), whereas participants with a higher education level (p=0.030), a higher income level (p=0.009), or individuals with a family member (p=0.028) or acquaintance (p=0.013) with a history of CRC preferred colonoscopy. Only 12.9% of participants had a bad experience with a previous FIT; however, 39.3% of participants had a bad experience with a previous colonoscopy.

Conclusions

Colonoscopy was preferred to FIT in a 2.2:1 ratio as the primary CRC screening test for the NCSP. Patients’ preference for colonoscopy should be considered for the NCSP in Korea.

Microbial markers in colorectal cancer detection and/or prognosis

Colorectal cancer (CRC) is the second leading cause of cancer worldwide. CRC is still associated with a poor prognosis among patients with advanced disease. On the contrary, due to its slow progression from detectable precancerous lesions, the prognosis for patients with early stages of CRC is encouraging. While most robust methods are invasive and costly, actual patient-friendly screening methods for CRC suffer of lack of sensitivity and specificity. Therefore, the development of sensitive, non-invasive and cost-effective methods for CRC detection and prognosis are necessary for increasing the chances of a cure. Beyond its beneficial functions for the host, increasing evidence suggests that the intestinal microbiota is a key factor associated with carcinogenesis. Many clinical studies have reported a disruption in the gut microbiota balance and an alteration in the faecal metabolome of CRC patients, suggesting the potential use of a microbial-based test as a non-invasive diagnostic and/or prognostic tool for CRC screening. This review aims to discuss the microbial signatures associated with CRC known to date, including dysbiosis and faecal metabolome alterations, and the potential use of microbial variation markers for non-invasive early diagnosis and/or prognostic assessment of CRC and advanced adenomas. We will finally discuss the possible use of these markers as predicators for treatment response and their limitations.

Flexible sigmoidoscopy in colorectal cancer screening: implications of different colonoscopy referral strategies

Flexible sigmoidoscopy (FS) screening reduces colorectal cancer incidence and mortality. Its potential to detect proximal neoplasms depends on colonoscopy referral. We estimated diagnostic performance of sigmoidoscopy using 12 different referral criteria in detecting colorectal cancer and advanced adenomas. Colonoscopy results from 14,947 participants of screening colonoscopy in Germany were used to derive sensitivity of sigmoidoscopy for colorectal cancer, advanced adenomas (AAs), and any advanced neoplasms in the proximal colon. It was assumed that FS detects the same neoplasms as colonoscopy within its reach and that distal neoplasms would be followed by colonoscopy. In addition, numbers of colonoscopies needed (NCN) to detect one proximal advanced neoplasm were calculated. The most advanced findings during colonoscopy were colorectal cancer in 213 subjects (1.4%), AA in 1539 subjects (10.2%) and non-advanced adenomas in 2988 subjects (19.8%). Without colonoscopy referral, overall sensitivities for any colorectal cancer, advanced adenoma and any advanced neoplasm (proximal or distal) would be 79, 65 and 66%, respectively. These sensitivities could be increased to up to 86, 83 and 84% by the referral strategies investigated. Compared to referral due to advanced adenomas, referral due to non-advanced adenomas would substantially increase the NCN at a modest gain in sensitivity. Sensitivities were higher and NCNs were lower in men than in women for every strategy. In conclusion, colonoscopy referral can substantially increase sensitivity of sigmoidoscopy-based screening, but the gain by referral due to non-advanced adenomas substantially increases NCN compared to referral due to advanced neoplasms only. Major sex differences may call for sex-specific referral strategies.

Effects of Training and Feedback on Accuracy of Predicting Rectosigmoid Neoplastic Lesions and Selection of Surveillance Intervals by Endoscopists Performing Optical Diagnosis of Diminutive Polyps

BACKGROUND & AIMS

Real-time differentiation of diminutive polyps (1-5 mm) during endoscopy could replace histopathology analysis. According to guidelines, implementation of optical diagnosis into routine practice would require it to identify rectosigmoid neoplastic lesions with a negative predictive value (NPV) of more than 90%, using histologic findings as a reference, and agreement with histology-based surveillance intervals for more than 90% of cases.

METHODS

We performed a prospective study with 39 endoscopists accredited to perform colonoscopies on participants with positive results from fecal immunochemical tests in the Bowel Cancer Screening Program at 13 centers in the Netherlands. Endoscopists were trained in optical diagnosis using a validated module (Workgroup serrAted polypS and Polyposis). After meeting predefined performance thresholds in the training program, the endoscopists started a 1-year program (continuation phase) in which they performed narrow band imaging analyses during colonoscopies of participants in the screening program and predicted histological findings with confidence levels. The endoscopists were randomly assigned to groups that received feedback or no feedback on the accuracy of their predictions. Primary outcome measures were endoscopists' abilities to identify rectosigmoid neoplastic lesions (using histology as a reference) with NPVs of 90% or more, and selecting surveillance intervals that agreed with those determined by histology for at least 90% of cases.

RESULTS

Of 39 endoscopists initially trained, 27 (69%) completed the training program. During the continuation phase, these 27 endoscopists performed 3144 colonoscopies in which 4504 diminutive polyps were removed. The endoscopists identified neoplastic lesions with a pooled NPV of 90.8% (95% confidence interval 88.6-92.6); their proposed surveillance intervals agreed with those determined by histologic analysis for 95.4% of cases (95% confidence interval 94.0-96.6). Findings did not differ between the group that did vs did not receive feedback. Sixteen endoscopists (59%) identified rectosigmoid neoplastic lesions with NPVs greater than 90% and selected surveillance intervals in agreement with those determined from histology for more than 90% of patients.

CONCLUSIONS

In a prospective study following a validated training module, we found that a selected group of endoscopists identified rectosigmoid neoplastic lesions with pooled NPVs greater than 90% and accurately selected surveillance intervals for more than 90% of patients over the course of 1 year. Providing regular interim feedback on the accuracy of neoplastic lesion prediction and surveillance interval selection did not lead to differences in those endpoints. Monitoring is suggested, as individual performance varied. ClinicalTrials.gov no: NCT02516748; Netherland Trial Register: NTR4635.

The diagnostic value of serum microRNA-183 and TK1 as biomarkers for colorectal cancer diagnosis

Objective

To evaluate the serum levels of microRNA-183 (miR-183) and thymidine kinase 1 (TK1) in colorectal cancer patients and their clinical value as biomarkers for colorectal cancer auxiliary diagnosis.

Methods

Forty-six pathology confirmed colorectal cancer patients and 46 healthy controls were included in this study. The serum levels of miR-183 and TK1 in colorectal cancer patients and healthy controls were examined by real-time PCR and chemiluminescence detection assay respectively. The diagnostic value of serum miR-183 and TK1 as tumor biomarkers for colorectal cancer detection was evaluated through receiver operating characteristic (ROC) curves.

Results

The median serum relative expression of miR-183 was 1.33 (0.34-5.65) and 0.88 (0.26-4.67) in colorectal cancer patients and healthy controls respectively with significant statistical difference (p<0.05). Using serum miR-183 as the diagnostic reference, the colorectal cancer diagnosis sensitivity, specificity and AUC was 65.22%, 63.04% and 0.69 respectively. The median serum level of TK1 was 3.33 (0.78-5.78) pmol/L and 0.99 (0.34-4.46) pmol/L in colorectal cancer patients and healthy controls respectively with significant statistical difference (p<0.05). The diagnostic sensitivity, specificity and AUC was 84.78%, 78.26% and 0.88 respectively forserum TK1 as reference for colorectal diagnosis. The pearson correlation test was used to evaluate the serum miR-183 and TK1 correlation in colorectal cancer patients. However, no significant correlation between serum miR-183 and TK1 was found in colorectal patients (p>0.05).

Conclusion

Serum levels of miR-183 and TK1 arepotential biomarkers for colorectal cancer auxiliary diagnosis.

Screening for colorectal cancer in Tianhe, Guangzhou: results of combining fecal immunochemical tests and risk factors for selecting patients requiring colonoscopy

Objective

To explore the performance of a protocol combining fecal immunochemical test (FIT) and a high-risk factor questionnaire (HRFQ) for selecting patients requiring colonoscopy as part of a population-based colorectal cancer (CRC) screening program in China.

Methods

From 2015 to 2016, we conducted a CRC screening program for all residents aged 45 years or older in Tianhe District, Guangzhou City, China. Participants underwent an FIT and received an HRFQ as part of primary screening. Those with positive FIT and/or HRFQ results were considered to be at high risk and were recommended to undergo colonoscopy.

Results

A total of 10 074 subjects were recruited and enrolled in the screening program. In the enrolled population, 17.5% had positive FIT results and 19.4% had positive HRFQ results. Of those recommended to undergo diagnostic colonoscopy, 773 did so. The screening method’s overall positive predictive value (PPV) was 4.9% for non-adenomatous polyps, 11.4% for low-risk adenomas (LRAs), 15.9% for high-risk adenomas (HRAs) and 1.6% for CRC. The PPVs of positive FIT results for non-adenomatous polyps, LRAs, HRAs and CRC were 5.2%, 15.9%, 22.5% and 2.5%, respectively. The PPVs of positive HRFQ results for non-adenomatous polyps, LRA, HRA and CRC were 4.1%, 10.2%, 14.3% and 1.4%, respectively. The PPVs associated with combined positive FIT and HRFQ results for non-adenomatous polyps, LRAs, HRAs and CRC were 4.5%, 16.4%, 23.7% and 2.8%, respectively.

Conclusion

Our results suggest that this two-step CRC screening strategy, involving a combination of FIT and HRFQ followed by colonoscopy, is useful to identify early-stage CRC. The high detection rates and PPVs for CRC and adenomas encourage this strategy’s use in ongoing screening programs.

Morphological classifications of gastrointestinal lesions

In the era of spreading adoption of gastrointestinal endoscopy screening worldwide, endoscopists encounter an increasing number of complex lesions in the gastrointestinal tract. For decision-making on optimal treatment, precise lesion characterization is crucial. Especially the assessment of potential submucosal invasion is of utmost importance as this determines whether endoscopic removal is an option and which technique should be used. To describe a lesion and stratify for the risk of submucosal invasion, several morphological classification systems have been developed. In this manuscript, we thoroughly discuss a systematic approach for the endoscopic assessment of a lesion, which include location, size, Paris classification, lateral spreading tumor classification if applicable and evaluation of the surface pattern with advanced endoscopic imaging techniques. The use of advanced imaging techniques improves the characterization of mucosal surface patterns and helps to determine whether lesions are amenable to endoscopic resection.

Natural history of diminutive and small colorectal polyps: a systematic literature review

BACKGROUND AND AIMS

Diminutive (1-5 mm) and small (6-9 mm) polyps comprise 90% of detected lesions during colonoscopy and rarely contain advanced histology or colorectal cancer (CRC). Routine removal of these lesions results in a significant burden to colonoscopy programs. At the same time, the risk for progression of these polyps to CRC is unclear. We performed a systematic review to explore the natural history of diminutive and small colorectal polyps.

METHODS

We searched MEDLINE and EMBASE for studies investigating the natural history of colorectal polyps. Studies were considered eligible when they assessed patients with 1- to 9-mm polyps that were not treated with polypectomy and that underwent follow-up. We excluded studies in patients with inflammatory bowel disease, polyposis syndromes, and previously diagnosed CRC. We independently extracted study characteristics and evaluated CRC and advanced adenoma (size ≥ 10 mm, containing high-grade dysplasia or villous features) as outcome parameters.

RESULTS

Of 8775 retrieved studies, 9 studies with 721 patients were included that prospectively evaluated the evolution of 1- to 9-mm polyps. In 7 studies the average duration of observation was 2 to 3 years. There was only 1 study in which 1 small polyp might have progressed to cancer. Of 1034 adenomas sized 1 to 9 mm in those studies, 6% progressed to advanced adenomas over time.

CONCLUSIONS

Based on this systematic review, it appears that some 1- to 9-mm adenomas progress to advanced adenomas within 2 to 3 years. No information on long-term CRC transition rates was found. Defining the biologic significance of these polyps is needed to balance between benefits and harm of polypectomy. (PROSPERO database registration number: CRD42016036577.).

External Validation of the Endoscopic Features of Sessile Serrated Adenomas in Expert and Trainee Colonoscopists

Background/Aims

It is unclear whether the endoscopic features of sessile serrated adenomas (SSAs) would be useful to trainee colonoscopists to predict SSA. Therefore, the present study aimed to identify features that expert and trainee colonoscopists can use to independently and reliably predict SSA by using high-resolution white-light endoscopy.

Methods

Endoscopic images of 81 polyps (39 SSAs, 22 hyperplastic polyps, and 20 tubular adenomas) from 43 patients were retrospectively evaluated by 10 colonoscopists (four experts and six trainees). Eight endoscopic features of SSAs were assessed for each polyp.

Results

According to multivariable analysis, a mucous cap (odds ratio [OR], 10.44; 95% confidence interval [CI], 5.72 to 19.07), indistinctive borders (OR, 4.21; 95% CI, 2.74 to 7.16), dark spots (OR, 3.64; 95% CI, 1.89 to 7.00), and cloud-like surface (OR, 2.43; 95% CI, 1.27 to 4.668) were independent predictors of SSAs. Among these, a mucous cap, indistinctive borders, and cloud-like surface showed moderate interobserver agreement (mean κ >0.40) among experts and trainees. When ≥1 of the three predictors was observed, the sensitivity and specificity for diagnosing SSAs were 79.0% and 81.4%, respectively.

Conclusions

Colonoscopy trainees and experts can use several specific endoscopic features to independently and reliably predict SSAs.

Adding family history to faecal immunochemical testing increases the detection of advanced neoplasia in a colorectal cancer screening programme

BACKGROUND

Faecal immunochemical testing (FIT) for colorectal cancer (CRC) screening has suboptimal sensitivity for detecting advanced neoplasia. To increase its performance, FIT could be combined with other risk factors.

AIM

To evaluate the incremental yield of a screening programme using a positive FIT or a CRC family history, to offer a diagnostic colonoscopy.

METHODS

For this post hoc analysis, data were collected in the colonoscopy arm of a colonoscopy or colonography for screening study. In this study, 6600 randomly selected, asymptomatic men and women (50-75 years) were invited for screening colonoscopy. 1112 Participants completed a FIT and a questionnaire prior to colonoscopy. We compared the yield of FIT-only and FIT combined with CRC family history, defined as having one or more first-degree relatives with CRC.

RESULTS

At a 10 μg Hb/g faeces FIT-positivity threshold the combined strategy would increase the yield from 36 (3.2%; CI: 2.4-4.5%) to 53 (4.8%; CI: 3.7-6.2%) cases of advanced neoplasia, at the expense of 148 additional negative colonoscopies. Sensitivity in detecting advanced neoplasia would increase from 36% (CI: 26-46%) to 52% (CI: 42-63%), whereas specificity would decrease from 93% (CI: 92-95%) to 79% (CI: 76-81%). The strategy will be preferred if one accepts 8.8 false positives for every additional participant in whom advanced neoplasia can be detected.

CONCLUSIONS

Offering colonoscopy to those with a positive FIT or CRC family history increases the yield of a FIT-based screening programme. Depending on the number of negative colonoscopies one accepts, this combined approach can be considered for improving CRC screening.