Improving protection against proximal colon cancer by colonoscopy

Sedated Colonoscopy may not be Beneficial for Polyp/Adenoma Detection

BACKGROUND

Sedated colonoscopy has been increasingly selected. However, the effect of sedated colonoscopy on polyp/adenoma detection rate (PDR/ADR) remains controversial among studies.

METHODS

In this retrospective study, the medical records of 11 504 consecutive patients who underwent colonoscopy at our department from July 1, 2021 to December 31, 2022 were collected. Patients were divided into sedated and unsedated groups according to the use of intravenous sedation during colonoscopy. Overall PDR/ADR, right-side, transverse, and left-side colon PDR/ADR, and single and multiple PDR/ADR were calculated. By adjusting for age, gender, body mass index, inpatient, screening/surveillance, cecal intubation time, colonoscopy withdrawal time ≥6 min, and an endoscopist's experience ≥5 years, multivariate logistic regression analyses were performed to evaluate the association of sedated colonoscopy with overall PDR/ADR, right-side, transverse, and left-side colon PDR/ADR, and single and multiple PDR/ADR, where the absence of PDR/ADR was used as reference. Odds ratios (ORs) with their 95% confidence intervals (CIs) were calculated.

RESULTS

Overall, 2275 patients were included, of whom 293 and 1982 underwent sedated and unsedated colonoscopy, respectively. Multivariate logistic regression analyses showed that sedated colonoscopy was independently associated with lower overall PDR/ADR (OR = 0.640, 95% CI = 0.460-0.889, P = 0.008), right-side colon PDR/ADR (OR = 0.591, 95% CI = 0.417-0.837, P = 0.003), single PDR/ADR (OR = 0.659, 95% CI = 0.436-0.996, P = 0.048), and multiple PDR/ADR (OR = 0.586, 95% CI = 0.402-0.855, P = 0.005), but not transverse or left-side colon PDR/ADR.

CONCLUSION

Sedated colonoscopy may not be beneficial in terms of overall PDR/ADR, right-side colon PDR/ADR, and number of polyps/adenomas. Thus, it should be selectively recommended. Additionally, it should be necessary to explore how to improve the quality of sedated colonoscopy.

Cap-assisted colonoscopy can increase the rate of sessile serrated lesion detection at the left lateral decubitus position: A retrospective case-control study

We investigated the effectiveness of cap-assisted colonoscopy conducted with the patient in the left lateral decubitus position at both the colonoscope's insertion and withdrawal timepoints compared to the effectiveness of colonoscopy without a cap conducted in the supine position at withdrawal. This was a case-control study, based on historical comparisons of patients over 2 time periods. The first group of patients underwent colonoscopies with a transparent cap and the patient was in the left lateral decubitus position at both the insertion and withdrawal timepoints from April to June 2019. The subsequent group underwent colonoscopies without a cap and with the patient in the supine position at withdrawal from July to September 2019. The rates of successful intubation, cecal intubation time, and number, size, shape, and location of the detected adenomas and sessile serrated lesions were compared between the 2 groups. Data from 644 colonoscopies (cap-assisted colonoscopy + left lateral decubitus position, n=320; other colonoscopies, n=324) were analyzed. The demographic characteristics and technical performances were similar. The SSL detection rate was significantly higher with cap-assisted colonoscopy and the left lateral decubitus position than with other colonoscopies (3.4% vs 0.93%, P=.029). The adenoma detection rates in the 2 groups were similar (31% and 28%, respectively, P=.43).Cap-assisted colonoscopy in the left lateral decubitus position may increase the detection rate of sessile serrated lesions compared to colonoscopy without a cap and supine position at withdrawal.

Sessile serrated lesions: Clinicopathological characteristics, endoscopic diagnosis, and management

The 2019 World Health Organization (WHO) Classification of Tumours of the Digestive System (5th edition) introduced the term "sessile serrated lesion" (SSL) to replace the term "sessile serrated adenoma/polyp" (SSA/P). SSLs are early precursor lesions in the serrated neoplasia pathway that result in colorectal carcinomas with BRAF mutations, methylation for DNA repair genes, a CpG island methylator phenotype, and high levels of microsatellite instability. Some of these lesions can rapidly become dysplastic or invasive carcinomas that exhibit high lymphatic invasion and lymph node metastasis potential. The 2019 WHO classification noted that dysplasia arising in an SSL most likely is an advanced polyp, regardless of the morphologic grade of the dysplasia. Detecting SSLs with or without dysplasia is critical; however, detection of SSLs is challenging, and their identification by endoscopists and pathologists is inconsistent. Furthermore, indications for their endoscopic treatment have not been established. Moreover, SSLs are considered to contribute to the development of post-colonoscopy colorectal cancers. Herein, the clinicopathological and endoscopic characteristics of SSLs, including features determined using white light and image-enhanced endoscopy, therapeutic indications, therapeutic methods, and surveillance are reviewed based on the literature. This information may lead to more intensive research to improve detection, diagnosis, and rates of complete resection of these lesions and reduce post-colonoscopy colorectal cancer rates.

Adult and Elderly Risk Factors of Mortality in 23,614 Emergently Admitted Patients with Rectal or Rectosigmoid Junction Malignancy

Background: Colorectal cancer, among which are malignant neoplasms of the rectum and rectosigmoid junction, is the fourth most common cancer cause of death globally. The goal of this study was to evaluate independent predictors of in-hospital mortality in adult and elderly patients undergoing emergency admission for malignant neoplasm of the rectum and rectosigmoid junction. Methods: Demographic and clinical data were obtained from the National Inpatient Sample (NIS), 2005−2014, to evaluate adult (age 18−64 years) and elderly (65+ years) patients with malignant neoplasm of the rectum and rectosigmoid junction who underwent emergency surgery. A multivariable logistic regression model with backward elimination process was used to identify the association of predictors and in-hospital mortality. Results: A total of 10,918 non-elderly adult and 12,696 elderly patients were included in this study. Their mean (standard deviation (SD)) age was 53 (8.5) and 77.5 (8) years, respectively. The odds ratios (95% confidence interval, P-value) of some of the pertinent risk factors for mortality for operated adults were 1.04 for time to operation (95%CI: 1.02−1.07, p < 0.001), 2.83 for respiratory diseases (95%CI: 2.02−3.98), and 1.93 for cardiac disease (95%CI: 1.39−2.70), among others. Hospital length of stay was a significant risk factor as well for elderly patients—OR: 1.02 (95%CI: 1.01−1.03, p = 0.002). Conclusions: In adult patients who underwent an operation, time to operation, respiratory diseases, and cardiac disease were some of the main risk factors of mortality. In patients who did not undergo a surgical procedure, malignant neoplasm of the rectosigmoid junction, respiratory disease, and fluid and electrolyte disorders were risk factors of mortality. In this patient group, hospital length of stay was only significant for elderly patients.

1L NER1006 can improve rates of adequate and high-quality bowel cleansing in the right colon: a post hoc analysis of two randomised clinical trials

BACKGROUND

The right colon is difficult to cleanse compared with other colon segments. This post hoc analysis of two randomised clinical trials (MORA and NOCT) examined whether 1L polyethylene glycol (PEG) NER1006 and two mid-volume alternatives could improve adequate and high-quality cleansing in the right colon among patients with complete cleansing assessments.

METHODS

Patients received NER1006 (N2D), 2L PEG plus ascorbate (2LPEG) or oral sulphate solution (OSS) as a 2-day evening/morning split-dosing regimen or NER1006 as a same-day morning-only dosing regimen (N1D). Patients had full segmental scoring assigned by treatment-blinded central readers using the Harefield Cleansing Scale. The right colon adequate (score ≥ 2) and high-quality (score ≥ 3) cleansing success of NER1006 (N2D and N1D) versus 2LPEG and OSS was analysed individually and as pooled groups (N2D vs. 2LPEG/OSS). We assessed the comparative right colon cleansing rates of the N2D versus 2LPEG/OSS in overweight males. We also performed a multivariable regression analysis to examine factors affecting cleansing in the right colon.

RESULTS

A total of 1307 patients were included. Pooled N2D showed significantly improved rates of adequate-level cleansing in the right colon compared with 2LPEG (97.5% [504/517] vs. 94.6% [246/260]; p = 0.020) and OSS (97.5% [504/517] vs. 93.8% [244/260]; p = 0.006). In MORA, the rate of adequate right colon cleansing did not significantly differ between N1D and 2LPEG (95.2% [257/270] vs. 94.6% [246/260]; p = 0.383). The rate of right colon high-quality cleansing was significantly improved with N2D or N1D vs. 2LPEG (p < 0.001 for both), and was numerically higher with N2D versus OSS (p = 0.11). In overweight males, NER1006 delivered numerically higher adequate (p = 0.398) and superior high-quality (p = 0.024) cleansing rates versus 2LPEG/OSS. Multivariable regression analysis showed NER1006 was associated with adequate and high-quality cleansing (p = 0.031 and p < 0.001), while time between preparation and colonoscopy was negatively associated (p = 0.034 and p = 0.006).

CONCLUSIONS

NER1006 delivered improved rates of adequate and high-quality right colon cleansing compared with 2LPEG and OSS. The increased rate of high-quality cleansing with NER1006 versus its comparators was also seen in overweight males.

Efficacy and Safety of TJP-008 Compared to 2 L PEG with Ascorbate in Colon Cleansing: A Randomized Phase 3 Trial

Background/Aims

Polyethylene glycol (PEG)-based bowel preparations are effective cleansing agents for colonoscopy. However, they require relatively large volumes to be used even with agents such as 2 L PEG with ascorbate (2LPEG). This phase 3, randomized, single-blinded, multicenter, parallel-group study compared the efficacy of 1 L PEG with high-dose ascorbate, TJP-008, to 2LPEG.

Methods

Patients undergoing colonoscopy were randomized (111) to receive TJP-008 as 1-day split dose (TJP-008-1) or 2-day split dose (TJP-008-2) regimen or to receive 2LPEG as a 2-day split dose regimen. Cleansing efficacy was evaluated using the Harefield Cleansing Scale. The primary endpoint was overall bowel cleansing success. Full analysis set (FAS) and per protocol set (PPS) analyses were performed.

Results

Of the 314 screened patients, efficacy was assessed in the following patient numbers (FAS/PPS) total (293/285), TJP-008-1 (98/94), TJP-008-2 (97/95), and 2LPEG (98/96). FAS revealed noninferiority between TJP-008 and 2LPEG with regard to overall success (TJP-008-2, 99.0%; TJP-008-1, 95.9%; 2LPEG, 94.9%; p=0.100 and p=0.733, respectively). PPS also showed noninferiority (p=0.721 and p=0.211, respectively). However, the PPS analyses showed a higher bowel cleansing score for TJP-008-2 for high-quality cleansing in the right colon (TJP-008-2 83.2% vs 2LPEG 62.5%; p=0.005).

Conclusions

TJP-008 is a new low-volume cleansing agent with a colon cleansing efficacy comparable to that of standard 2LPEG that exhibits significant safety and tolerability.

Chronic constipation is negatively associated with colonic diverticula

OBJECTIVES

Constipation has been considered the key risk factor for diverticulosis occurrence, but the underlying mechanism is unclear. We investigated the factors associated with diverticulosis, focusing on the association of constipation severity with the localization and number of diverticula.

MATERIALS AND METHODS

We analyzed consecutive patients who underwent colonoscopy between March and December 2019. Chronic constipation was diagnosed as constipation meeting Rome IV criteria or as that requiring laxative therapy for more than 6 months. The degree of constipation was scored using the Constipation Scoring System (CSS).

RESULTS

We assessed 1014 patients. Multivariate analysis revealed that age, alcohol consumption, and hypertension were positively associated with diverticulosis, whereas chronic constipation was negatively associated with diverticulosis (odds ratio [OR] = 0.74; 95% confidence interval [CI], 0.55-0.99). When assessed according to the location of diverticula, right-sided diverticula were significantly associated with a lower incidence of constipation (OR = 0.94; 95% CI, 0.89-0.98), whereas neither left-sided nor bilateral diverticula was associated with constipation. This negative association of diverticula with constipation was stronger in patients with a high CSS score. In stratified analysis, the number of diverticula decreased with increasing degree of constipation (p for trend <.01), and a high CSS score was associated with a decreased prevalence of ≥3 diverticula (OR = 0.64; 95% CI, 0.44-0.99).

CONCLUSIONS

Chronic constipation was negatively associated with colonic diverticulosis. The association increased with the degree of constipation and was strong only in cases with right-sided diverticula and those with ≥3 diverticula.

The importance of colonoscopy bowel preparation for the detection of colorectal lesions and colorectal cancer prevention

Background and study aims  Colonoscopy for colorectal cancer (CRC) screening has reduced CRC incidence and mortality and improved prognosis. Optimal bowel preparation and high-quality endoscopic technique facilitate early CRC detection. This review provides a narrative on the clinical importance of bowel preparation for colonoscopy and highlights available bowel preparations. Methods  A PubMed search was conducted through June 2019 to identify studies evaluating clinical outcomes, efficacy, safety, and tolerability associated with bowel preparation for CRC screening-related colonoscopy. Results  Selecting the optimal bowel preparation regimen is based on considerations of efficacy, safety, and tolerability, in conjunction with individual patient characteristics and preferences. Available bowel preparations include high-volume (4 L) and low-volume (2 L and 1 L), polyethylene glycol (PEG) solutions, sodium sulfate, sodium picosulfate/magnesium oxide plus anhydrous citric acid, sodium phosphate tablets, and the over-the-counter preparations magnesium citrate and PEG-3350. These preparations may be administered as a single dose on the same day or evening before, or as two doses administered the same day or evening before/morning of colonoscopy. Ingesting at least half the bowel preparation on the day of colonoscopy (split-dosing) is associated with higher adequate bowel preparation quality versus evening-before dosing (odds ratio [OR], 2.5; 95 % confidence interval [CI], 1.9-3.4). Conclusions  High-quality bowel preparation is integral for optimal CRC screening/surveillance by colonoscopy. Over the last 30 years, patients and providers have gained more options for bowel preparation, including low-volume agents with enhanced tolerability and cleansing quality that are equivalent to 4 L preparations. Split-dosing is preferred for achieving a high-quality preparation.

Clinicopathological features, diagnosis, and treatment of sessile serrated adenoma/polyp with dysplasia/carcinoma

Sessile serrated adenoma/polyps (SSA/Ps) are early precursor lesions in the serrated neoplasia pathway, which results in BRAF-mutated colorectal carcinomas with not only high levels of microsatellite instability but also microsatellite stable. SSA/Ps with advanced histology, including cytological dysplasia or minimally invasive carcinomas, are important lesions because SSA/Ps are considered major contributors to "interval cancers" and these lesions can rapidly become dysplastic or invasive carcinomas. Clinicopathologically, SSA/Ps with dysplasia or invasive carcinoma were associated with advanced age, female sex, and proximal colon. Although SSA/Ps with submucosal invasive carcinoma were smaller and invaded less deeply into the submucosal layer than conventional tubular adenomas with submucosal invasive carcinoma, SSA/Ps with submucosal invasive carcinoma frequently had a mucinous component and exhibited a higher potential for lymphatic invasion and lymph node metastasis. In an SSA/P series, endoscopic characteristics, including (semi)pedunculated morphology, double elevation, central depression, and reddishness, may help accurately diagnose SSA/Ps with advanced histology. Removal of SSA/Ps with dysplasia or invasive carcinoma was recommended. Endoscopic treatment such as endoscopic mucosal resection or endoscopic submucosal dissection is useful for those lesions. However, surgical resection with lymph node dissection might be indicated when SSA/Ps with invasive carcinoma are endoscopically suspected, because these have the high risk of lymph node metastasis. Greater awareness may promote further research into improving the detection, recognition, and complete resection rates of SSA/Ps with dysplasia or invasive carcinoma and reduce the interval cancer rates.

G-EYE colonoscopy is superior to standard colonoscopy for increasing adenoma detection rate: an international randomized controlled trial (with videos)

BACKGROUND AND AIMS

Colorectal cancer (CRC) is largely preventable with routine screening and surveillance colonoscopy; however, interval cancers arising from precancerous lesions missed by standard colonoscopy still occur. An increased adenoma detection rate (ADR) has been found to be inversely associated with interval cancers. The G-EYE device includes a reusable balloon integrated at the distal tip of a standard colonoscope, which flattens haustral folds, centralizes the colonoscope's optics, and reduces bowel slippage. The insufflated balloon also aims to enhance visualization of the colon during withdrawal, thereby increasing the ADR.

METHODS

In this randomized, controlled, international, multicenter study (11 centers), patients (aged ≥50 years) referred to colonoscopy for screening, surveillance, or changes in bowel habits were randomized to undergo either balloon-assisted colonoscopy by using an insufflated balloon during withdrawal or standard high-definition colonoscopy. The primary endpoint was the ADR.

RESULTS

One thousand patients were enrolled between May 2014 and September 2016 to undergo colonoscopy by experienced endoscopists; 803 were finally analyzed (standard colonoscopy n = 396; balloon-assisted colonoscopy n = 407). Baseline parameters were similar in both groups. Balloon-assisted colonoscopy provided a 48.0% ADR compared with 37.5% in the standard colonoscopy group (28% increase; P = .0027). Additionally, balloon-assisted colonoscopy provided for a significant increase in detection of advanced (P = .0033) flat adenomas (P < .0001) and sessile serrated adenomas/polyps (P = .0026).

CONCLUSION

Balloon-assisted colonoscopy yielded a higher ADR and increased the detection of advanced, flat, and sessile serrated adenomas/polyps when compared with standard colonoscopy. Improved detection by the G-EYE device could impact the quality of CRC screening by reducing miss rates and consequently reducing interval cancer incidence. (Clinical trial registration number: NCT01917513.).

Frequency and Characteristics of Interval Colorectal Cancer in Actual Clinical Practice: A KASID Multicenter Study

Background/Aims

The aims of the present study were to determine the frequency of interval colorectal cancers (CRCs) after surveillance colonoscopy and to compare the clinicopathologic features and survival outcomes with those of non-interval CRCs.

Methods

From January 2003 to December 2013, 66,016 follow-up colonoscopies for 38,412 patients performed within recommended time were reviewed retrospectively based on data from 11 tertiary hospitals in South Korea. To compare clinicopathologic features and survival rates for interval CRC, 106 patients with non-interval CRC matched in age and gender were included.

Results

Among the 66,016 colonoscopies performed within the surveillance period, 63 cases (63/66,016) of interval CRC were detected, and 53 were finally included in the analysis. The mean age was 69.9±8.8 years, and the male to female ratio was 1.94:1. Although the occurrence rate of cancer in the right side colon was higher than that of non-interval CRC, interval CRCs were predominantly left sided. Other clinicopathologic features and overall survival were not significantly different between the two groups. Missed lesion was suspected to be the most common cause (29 cases, 54.7%).

Conclusions

The frequency of interval CRC among patients who had undergone a surveillance colonoscopy was 0.095%. While sharing some similar clinical features and survival outcomes, interval CRCs in Korea developed more often in males and on the left side in contrast to results from Western studies.

Risk factors associated with the detection and missed diagnosis of colorectal flat adenoma: a Chinese multicenter observational study

OBJECTIVES

Flat colorectal adenomas have a high risk of malignancy; however, their detection is often difficult due to their flat morphology. In this retrospective, large-scale study, we investigated the prevalence and characteristics of flat adenomas in a population in China.

METHODS

We analyzed the data collected for 16951 consecutive patients who underwent colonoscopy at four participating hospitals between September 2013 and September 2015. All colonoscopies were performed without magnification.

RESULTS

Among the 1,6951 patients, 2938 (17.3%) had adenoma and 796 (4.7%) had flat adenomas. The detection of flat adenoma showed a weak correlation with the detection of adenoma (r = 0.666). Multivariable logistic regression analysis revealed the following independent factors influencing the detection of flat adenomas: patient-related factors of age, presence of warning symptoms, history of adenomas and bowel preparation as well as endoscopist-related factors of endoscopist's level of proficiency, number of colonoscopy operators and withdrawal time.

CONCLUSIONS

The prevalence of flat adenomas in our study on Chinese patients was consistent with that reported from other countries. Factors conducive to the detection of flat adenomas were patient age of > 60 years, warning symptoms, history of adenoma, good bowel preparation, experienced endoscopist, single-operator colonoscopy and colonoscopy withdrawal time of >6 min.

Recent Advances in Diagnostic Colonoscopy for Colorectal Cancer Screening: An Update for Radiologists

OBJECTIVE

Colonoscopy accuracy in detecting colorectal neoplasia is critical for colorectal cancer prevention but has been shown to be operator- and technology-dependent. This article will discuss several recent improvements in the technique and technology of colonoscopy.

CONCLUSION

More rigorous training and retraining programs, active monitoring of endoscopist technique and outcomes, and exclusion of poorly performing endoscopists are urgently needed to improve the ultimate efficacy of colorectal cancer screening programs.

The clinical impact of serrated colorectal polyps

Serrated polyps (SPs) of the colorectum pose a novel challenge to practicing gastroenterologists. Previously thought benign and unimportant, there is now compelling evidence that SPs are responsible for a significant percentage of incident colorectal cancer worldwide. In contrast to conventional adenomas, which tend to be slow growing and polypoid, SPs have unique features that undermine current screening and surveillance practices. For example, sessile serrated polyps (SSPs) are flat, predominately right-sided, and thought to have the potential for rapid growth. Moreover, SSPs are subject to wide variations in endoscopic detection and pathologic interpretation. Unfortunately, little is known about the natural history of SPs, and current guidelines are based largely on expert opinion. In this review, we outline the current taxonomy, epidemiology, and management of SPs with an emphasis on the clinical and public health impact of these lesions.

A randomized trial to compare the efficacy and tolerability of sodium picosulfate-magnesium citrate solution vs. 4 L polyethylene glycol solution as a bowel preparation for colonoscopy

PURPOSE

The purpose of this study is to compare the efficacy and acceptability of an evening-before regimens of sodium picosulfate/magnesium citrate (SPMC) and polyethylene glycol (PEG) as bowel cleansers and to explore the results of a same-day regimen of SPMC.

METHODS

Multicenter, randomized, observer-blinded, parallel study carried out in subjects who were 18-80 years old and were undergoing diagnostic colonoscopy for the first time. The primary outcome was treatment success, which was a composite outcome defined by (1) the evaluation of the overall preparation quality as "excellent" or "good" by two blinded independent evaluators with the Fleet(®) Grading Scale for Bowel Cleansing and (2) a subject's acceptability rating of "easy to take" or "tolerable." The primary outcome was analyzed using a logistic regression with site, gender, and age group (age ≥65 years and <65 years) as factors.

RESULTS

Four hundred ninety subjects were included in the efficacy evaluation. Although treatment success was significantly higher in subjects assigned to the evening-before regimen of SPMC vs. subjects assigned to the evening-before PEG, when evaluating the two individual components for treatment success, there were significant differences in the ease of completion but not in the quality of preparation. The same-day SPMC regimen was superior to both the evening-before regimen of SPMC and PEG in terms of the quality of preparation, especially regarding the proximal colon.

CONCLUSIONS

An evening-before regimen of SPMC is superior to an evening-before regimen of PEG in terms of subject's acceptability. The same-day SPMC regimen provides better cleansing levels in the proximal colon.

Low-residue breakfast during the preparation for colonoscopy using a polyethylene glycol electrolyte solution: a randomised non-inferiority trial

Goals

To test the hypothesis that the use of a low-residue breakfast (LRB) the day prior to colonoscopy was not inferior to consuming clear fluids alone (CFD) in patients undergoing outpatient colonoscopy with a polyethylene glycol (PEG) bowel preparation.

Background

Optimal colon cleansing is essential for complete visualisation of the mucosa during colonoscopy. Few studies have examined the effect of diet on the quality of bowel cleansing or tolerance in patients using a PEG bowel preparation for colonoscopy.

Methods

Randomised, single-blinded non-inferiority trial. Adult patients scheduled for outpatient colonoscopy with PEG solution were randomised to an LRB followed by clear fluids or CFD using either a traditional or split-dose PEG solution for bowel preparation. The primary outcome was colon cleansing based on the Ottawa Bowel Preparation Score (OBPS).

Results

On an intention-to-treat (ITT) basis, a total of 109 and 105 patients were included in the CFD and LRB arms, respectively, with 116 and 98 patients, respectively, for the per-protocol (PP) analysis. Although there was no difference in the mean total OBPS between the CFD or LRB arms in either the ITT or PP analysis, the threshold for non-inferiority was not met. Patient acceptance of the regimens was higher in the LRB arm than in the CFD arm in the ITT and PP analyses.

Conclusions

This study failed to show the non-inferiority of an LRB in patients receiving bowel preparation with a PEG-based solution. A CFD should be prescribed when using a PEG bowel preparation.

Trial registration number

This trial is registered at ClinicalTrials.gov (NCT01454388).

Impact of the quality of bowel cleansing on the efficacy of colonic cancer screening: a prospective, randomized, blinded study

OBJECTIVES

Efficacy of two low volume bowel cleansing preparations, polyethylene glycol plus ascorbate (PEG + Asc) and sodium picosulfate/magnesium citrate (NaPic/MgCit), were compared for polyp and adenoma detection rate (PDR and ADR) and overall cleansing ability. Primary endpoint was PDR (the number of patients with ≥ 1 polypoid or flat lesion recorded by the colonoscopist).

METHODS

Diagnostic, surveillance or screening colonoscopy patients were enrolled into this investigator-blinded, multi-center Phase IV study and randomized 1:1 to receive PEG + Asc (administered the evening before and the morning of colonoscopy, per label) or NaPic/MgCit (administered in the morning and afternoon the day before colonoscopy, per label). The blinded colonoscopist documented any lesion and assessed cleansing quality (Harefield Cleansing Scale).

RESULTS

Of 394 patients who completed the study, 393 (PEG + Asc, N = 200; NaPic/MgCit, N = 193) had a colonoscopy. Overall PDR for PEG+Asc versus NaPic/MgCit was 51.5% versus 44.0%, p = 0.139. PDR and ADR on the right side of the bowel were significantly higher with PEG + Asc versus NaPic/MgCit (PDR: 56[28.0%] versus 32[16.6%], p = 0.007; ADR: 42[21.0%] versus 23[11.9%], p = 0.015), as was detection of flat lesions (43[21.5%] versus 25[13.0%], p = 0.025). Cleansing quality was better with PEG + Asc than NaPic/MgCit (98.5% versus 57.5% considered successful cleansing). Overall, there were 132 treatment-emergent adverse events (93 versus 39 for PEG+Asc and NaPic/MgCit, respectively). These were mainly mild abdominal symptoms, all of which were reported for higher proportions of patients in the PEG+Asc than NaPic/MgCit group. Twice as many patients in the NaPic/MgCit versus the PEG + Asc group reported tolerance of cleansing solution as 'very good'.

CONCLUSIONS

Compared with NaPic/MgCit, PEG + Asc may be more efficacious for overall cleansing ability, and subsequent detection of right-sided and flat lesions. This is likely attributable to the different administration schedules of the two bowel cleansing preparations, which may positively impact the detection and prevention of colorectal cancer, thereby improving mortality rates.

TRIAL REGISTRATION

ClinicalTrials.gov NCT01689792.

Stability of increased adenoma detection at colonoscopy. Follow-up of an endoscopic quality improvement program-EQUIP-II

OBJECTIVES

We recently completed a randomized controlled trial of an endoscopic quality improvement program (EQUIP) that demonstrated an improved adenoma detection rate (ADR) through simple educational interventions. The aim of this study (phase III) is to examine whether the improvement in ADR in the trained endoscopists remained stable with further follow-up.

METHODS

We prospectively followed up 15 staff endoscopists who had previously been randomized to a quality improvement intervention. In the current study, we examined an additional 1,200 colonoscopy procedures conducted over a 5-month time period following the original study, referred to as phase III. During this time, all physicians received quarterly ADR and other quality metric feedback, and the previous control group was offered the educational intervention voluntarily. ADRs and adenoma per patient (APP) rates were estimated in the endoscopists who were and were not randomized to EQUIP training and compared with those obtained in phases I and II of the original study. The study was conducted in a tertiary care Academic Medical Center. The study sample comprised 1200 patients undergoing routine colonoscopy. The main outcome measurement was adenoma detection rate.

RESULTS

The previously observed increase in ADR in the trained group from 36% in phase I to 47% in phase II was maintained into phase III (46%). The ADR of the untrained group remained unchanged from phase I (36%) to phase II (35%); it was increased only marginally in phase III to 39%, which was still lower than the 46% ADR in the trained group. The trained group had an increase in APP, from 0.72 in Phase I to 0.87 in Phase II and 0.98 in Phase III. For the previously untrained group, there was no change in APP from phase I (0.68) to phase II (0.68), but there was possibly a small increase (to 0.74) in Phase III.

CONCLUSIONS

This study provides evidence that improvements in ADR obtained through the endoscopic quality-training program can persist for at least 5 months after completion of the program. It further suggests that a focus on ADR does not lead to a "one and done" phenomenon. The limitations of this study were as follows: single-center setting, and lack of sessile polyp information/standardization.

Patient age and duration of colonoscopy are predictors for adenoma detection in both proximal and distal colon

AIM: To investigate the relation of patient characteristics and procedural parameters to the endoscopic detection rate of colonic adenomas. Further to study, which factors may be capable to predict the localization of adenomatous lesions.

METHODS: We used the data base of a prospective randomized colonoscopy study (The ColoCap trial) to identify patients being diagnosed with colon adenoma. Logistic regression analysis was conducted to reveal predictors for adenoma detection in the entire colon and also with respect to the proximal and distal part. Covariates including age, gender, duration of colonoscopy and comorbidities were defined to determine association between predictors and adenoma detection.

RESULTS: Equal numbers of adenomas were detected in the proximal and distal side of the splenic flexure [126 (57%) vs 94 (43%), P = 0.104]. Simultaneous occurrence of adenomas in both sides of the colon was rare. The appearance of both proximal and distal adenoma was associated with increasing age (P = 0.008 and P = 0.024) and increasing duration of colonoscopy (P < 0.001 and P = 0.001). Male gender was a predictor for adenoma detection in the proximal colon (P = 0.008) but statistical significance was slightly missed with respect to the distal colon (P = 0.089). Alcohol abuse was found to be a predictor for the detection of distal adenoma (P = 0.041).

CONCLUSION: Increasing age and longer duration of colonoscopy are factors with a strong impact on adenoma detection both in the proximal and distal colon. Since proximal adenomas occurred in absence of distal adenomas, complete colonoscopy should be performed for screening.

Anatomic and advanced adenoma detection rates as quality metrics determined via natural language processing

OBJECTIVES

The objectives of this study were to use an open-source natural language-processing tool (NLP) to accurately assess total, anatomic (left and right colon), and advanced adenoma detection rates (ADRs) and to determine how these metrics differ between high- and low-performing endoscopists.

METHODS

An NLP tool was developed using the Apache Unstructured Information Management Architecture and queried all procedure records for screening colonoscopies performed in patients aged 50-75 years at a single institution from April 1998 to December 2013. Validation was performed on 200 procedures and associated pathology reports. The total, left colon, right colon, and advanced ADRs were calculated and physicians were stratified by total ADR (<20% and ≥20%). Comparisons of colonoscopy characteristics and ADR comparisons (advanced, left, right, and right/left ratio) were determined by t-tests and Wilcoxon rank-sum tests.

RESULTS

The total ADR for 34,998 screening colonoscopies from 1998 to 2013 was 20.3%, as determined via NLP. The institutional left and right colon ADRs were 10.1% and 12.5%, respectively. The overall advanced ADR was 4.4%. Endoscopists with total ADRs ≥20% had higher left (12.4%) and right colon (16.4%) ADRs than endoscopists with ADRs <20% (left ADR=5.6%, right ADR=5.8%). Endoscopists with ADRs ≥20% had higher individual right/left ADR ratios than those with low ADRs (1.4 (interquartile range (IQR) 0.4) vs. 1.0 (IQR 0.4), P=0.02). There was a moderate positive correlation between advanced ADR detection and both right (Spearman's rho=0.5, P=0.05) and left colon (Spearman's rho=0.4, P=0.03) ADRs.

CONCLUSIONS

Institutions should consider the use of anatomic and advanced ADRs determined via natural language processing as a refined measure of colonoscopy quality. The ability to continuously monitor and provide feedback on colonoscopy quality metrics may encourage endoscopists to refine technique, resulting in overall improvements in adenoma detection.

Risk factors associated with missed colorectal flat adenoma: A multicenter retrospective tandem colonoscopy study

AIM: To determine the miss rate for colorectal flat adenomas during colonoscopy and the risk factors.

METHODS: Flat adenomas are frequently missed during colonoscopy. However, the risk factors that influence their miss rates are unclear. This was a multicenter, retrospective study in which patients diagnosed with colorectal adenomas at a diagnostic colonoscopy and followed within 3 mo by a second therapeutic colonoscopy were pooled out from the established database. The “per-patient” and “per-adenoma” adenoma miss rates (AMR) for overall adenomas and flat adenomas, and patient-, adenoma-, and procedure-related risk factors potentially associated with the “per-adenoma” AMR for flat adenomas were determined.

RESULTS: Chromoscopy and high-definition colonoscopy were not taken under consideration in the study. Among 2093 patients with colorectal adenomas, 691 (33.0%) were diagnosed with flat adenomas, 514 with concomitant protruding adenomas and 177 without. The “per-patient” AMR for flat adenomas was 43.3% (299/691); the rates were 54.3% and 11.3%, respectively, for those with protruding adenomas and those without (OR = 9.320, 95%CI: 5.672-15.314, χ² = 99.084, P < 0.001). The “per-adenoma” AMR for flat adenomas was 44.3% (406/916). In multivariate analysis, older age, presence of concomitant protruding adenomas, poor bowel preparation, smaller adenoma size, location at the right colon, insufficient experience of the colonoscopist, and withdrawal time < 6 min were associated with an increased “per-adenoma” AMR for flat adenomas. The AMR for flat adenomas was moderately correlated with that for overall adenomas (r = 0.516, P < 0.0001). The AMR for flat adenomas during colonoscopy was high.

CONCLUSION: Patient’s age, concomitant protruding adenomas, bowel preparation, size and location of adenomas, proficiency of the colonoscopist, and withdrawal time are factors affecting the “per-adenoma” AMR for flat adenomas.

Simple clinical risk score identifies patients with serrated polyps in routine practice

Large, proximal, or dysplastic (LPD) serrated polyps (SP) need accurate endoscopic recognition and removal as these might progress to colorectal cancer. Herewith, we examined the risk factors for having ≥1 LPD SP. We developed and validated a simple SP risk score as a potential tool for improving their detection. We reviewed clinical, endoscopic, and histologic features of serrated polyps in a study of patients undergoing elective colonoscopy (derivation cohort). A self-administered questionnaire was obtained. We conducted logistic regression analyses to identify independent risk factors for having ≥1 LPD SP and incorporated significant variables into a clinical score. We subsequently tested the performance of the SP score in a validation cohort. We examined 2,244 patients in the derivation and 2,402 patients in the validation cohort; 6.3% and 8.2% had ≥1 LPD SP, respectively. Independent risk factors for LPD SPs were age of more than 50 years [OR 2.2; 95% confidence interval (CI), 1.3-3.8; P = 0.004], personal history of serrated polyps (OR 2.6; 95% CI, 1.3-4.9; P = 0.005), current smoking (OR 2.2; 95% CI, 1.4-3.6; P = 0.001), and nondaily/no aspirin use (OR 1.8; 95% CI, 1.1-3.0; P = 0.016). In the validation cohort, a SP score ≥5 points was associated with a 3.0-fold increased odds for LPD SPs, compared with patients with a score <5 points. In the present study, age of more than 50 years, a personal history of serrated polyps, current smoking, and nondaily/no aspirin use were independent risk factors for having LPD SPs. The SP score might aid the endoscopist in the detection of such lesions.

Reduced type II interleukin-4 receptor signalling drives initiation, but not progression, of colorectal carcinogenesis: evidence from transgenic mouse models and human case-control epidemiological observations

We investigated the role of interleukin (IL)-4 receptor (IL-4R) signalling during mouse carcinogen-induced colorectal carcinogenesis and in a case–control genetic epidemiological study of IL-4Rα single nucleotide polymorphisms (SNPs). Azoxymethane-induced aberrant crypt focus (ACF; 6 weeks) and tumours (32 weeks) were analysed in wild-type (WT) BALB/c mice, as well as in IL-4Rα^−/−, IL-13^−/− and ‘double-knockout’ (DKO) animals. Colorectal cancer (CRC) cases (1502) and controls (584) were genotyped for six coding IL-4Rα SNPs. The association with CRC risk and CRC-specific mortality was analysed by logistic regression. Lack of IL-4Rα expression was associated with increased ACFs [median 8.5 ACFs per mouse (IL-4Rα^−/−) versus 3 (WT); P = 0.007], but no difference in the number of colorectal tumours [mean 1.4 per mouse (IL-4Rα^−/−) versus 2 (WT)], which were smaller and demonstrated reduced nuclear/cytoplasmic β-catenin translocation compared with WT tumours. Tumour-bearing IL-4Rα^−/− mice had fewer CD11b⁺/Gr1⁺ myeloid-derived suppressor splenocytes than WT animals. IL-13^−/− mice developed a similar number of ACFs to IL-4Rα^−/− and DKO mice. There was a significant increase in CRC risk associated with the functional SNP Q576R [odds ratio 1.54 (95% confidence interval 0.94–2.54), P_trend 0.03 for the minor G allele]. There was no effect of IL-4Rα genotype on either CRC-specific or all-cause mortality. These combined pre-clinical and human data together demonstrate that reduced IL-4R signalling has stage-specific effects on colorectal carcinogenesis (increased CRC initiation and risk but reduced tumour progression and no effect on CRC mortality). These results should prompt evaluation of the effect of pharmacological manipulation of IL-4R signalling on future CRC risk and for CRC treatment.

Prevalence of proximal serrated polyps and conventional adenomas in an asymptomatic average-risk screening population

Background/Aims

Detection of proximal serrated polyps (PSPs) is increasingly recognized as a new qualitative target for colonoscopy. The aims of this study were to assess the detected prevalence of PSPs and synchronous adenomas in an asymptomatic average-risk screening cohort and to evaluate potential factors associated with detection of PSPs.

Methods

The study included 1,375 asymptomatic average-risk Korean patients (aged 50 years or older) who underwent screening colonoscopy. In total, 1,710 polyps were evaluated pathologically.

Results

The overall PSP detection rate (PSPDR) was low at 3.1%, despite high polyp (54.0%) and adenoma detection rates (ADRs, 43.5%). ADR did not correlate with PSPDR, but it was strongly correlated with PDR (r=0.810; p<0.001). Patients with PSPs were more likely to have longer withdrawal time and more proximal colon adenomas than patients without PSPs (adjusted odds ratio [OR], 1.19; 95% confidence interval [CI], 1.09 to 1.31; p<0.001) (adjusted OR, 2.03; 95% CI, 1.06 to 3.88; p=0.031, respectively).

Conclusions

The detected prevalence of PSPs was low (<5%) in an asymptomatic average-risk screening Korean population, despite the high prevalence of conventional adenomas. A longer mucosal inspection of the proximal colon may serve as a practical method to enhance detection of PSPs.

Modifiable endoscopic factors that influence the adenoma detection rate in colorectal cancer screening colonoscopies

BACKGROUND

Adenoma detection rate (ADR) has become the most important quality indicator for colonoscopy.

OBJECTIVE

The aim of this study was to investigate which modifiable factors, directly related to the endoscopic procedure, influenced the ADR in screening colonoscopies.

DESIGN

Observational, nested study.

SETTING

Multicenter, randomized, controlled trials.

PATIENTS

Asymptomatic people aged 50 to 69 years were eligible for a multicenter, randomized, controlled trial designed to compare colonoscopy and fecal immunochemical testing in colorectal cancer screening. A total of 4539 individuals undergoing a direct screening colonoscopy were included in this study.

INTERVENTION

Colonoscopy.

MAIN OUTCOME MEASUREMENTS

Bowel cleansing, sedation, withdrawal time in normal colonoscopies, and cecal intubation were analyzed as possible predictors of adenoma detection by using logistic regression analysis, adjusted for age and sex.

RESULTS

In multivariate analysis, after adjustment for age and sex, factors independently related to the ADR were a mean withdrawal time longer than 8 minutes (odds ratio [OR] 1.51; 95% CI, 1.17-1.96) in normal colonoscopies and split preparation (OR 1.26; 95% CI, 1.01-1.57). For advanced adenomas, only withdrawal time maintained statistical significance in the multivariate analysis. For proximal adenomas, withdrawal time and cecal intubation maintained independent statistical significance, whereas only withdrawal time longer than 8 minutes and a <10-hour period between the end of preparation and colonoscopy showed independent associations for distal adenomas.

LIMITATIONS

Only endoscopic variables have been analyzed.

CONCLUSION

Withdrawal time was the only modifiable factor related to the ADR in colorectal cancer screening colonoscopies associated with an increased detection rate of overall, advanced, proximal, and distal adenomas.

Benefits and limitations of cap-fitted colonoscopy in screening colonoscopy

BACKGROUND

Colonoscopy is widely used to detect colorectal cancer and to remove precancerous lesions to reduce the risk of colonic cancer.

AIMS

To examine the benefits and limitations of cap-fitted colonoscopy compared to conventional colonoscopy in terms of technical performance and colorectal adenoma detection rate.

METHODS

Screening colonoscopies performed from 2009 to 2010 with or without a transparent cap were retrospectively examined to compare the rate of successful intubation, cecal intubation time, and number, size, shape, and location of adenomas detected. An inclusion criterion was visualization of >95 % of the right colon.

RESULTS

Data from 2,301 colonoscopies (1,165 with cap-fitted colonoscopy, 1,136 without the transparent cap) were retrospectively analyzed. Procedures were performed by four experienced endoscopists. The subjects' demographic characteristics and technical performances were similar between the two methods. The only significant difference in the technical performance between the two techniques was a shorter cecal intubation time with cap-fitted colonoscopy (5.3 vs. 6.6 min; p = 0.045) by one endoscopist. The total number of adenomas detected was significantly higher with cap-fitted colonoscopy than without the cap (586 vs. 484, respectively; p < 0.0001). Adenoma detection with cap-fitted endoscopy was significantly higher in the right colon than in the left colon (19 vs. 12 %, respectively; p = 0.0001).

CONCLUSION

Cap-fitted colonoscopy did not improve the technical aspects of colonoscopy but significantly increased adenoma detection, especially in the right colon. It did not increase the detection rate of flat or depressed adenomas.

Interval cancers after colonoscopy-insights and recommendations

Several studies have raised warnings about the limited effectiveness of colonoscopy for the prevention of colorectal cancer (CRC), especially of the proximal colon. Two major categories of factors might be responsible for the development of interval cancers, namely technical, endoscopist-dependent factors and biological characteristics of the cancer that lead to more rapid tumour progression. Recognition of endoscopist-dependent factors is critical, as these factors are probably amenable to correction through improved awareness and education of endoscopists, using quality metrics (such as adenoma detection rates and cecal intubation rates) for objective evaluation and feedback. In this article, the current literature regarding the incidence of, and potential explanations for, interval CRCs is outlined. Although there is probably an interaction between technical and biology-related factors--and an attempt to dissect the biology from the technology might be fraught with difficulties--a structured analysis of individual cases of interval cancer might help in the continuous monitoring of the quality of colonoscopy, and ultimately might reduce the number of interval CRCs.

Evaluation of magnifying colonoscopy in the diagnosis of serrated polyps

AIM

To elucidate the colonoscopic features of serrated lesions of the colorectum using magnifying colonoscopy.

METHODS

Broad division of serrated lesions of the colorectum into hyperplastic polyps (HPs), traditional serrated adenomas (TSAs), and sessile serrated adenomas/polyps (SSA/Ps) has been proposed on the basis of recent molecular biological studies. However, few reports have examined the colonoscopic features of these divisions, including magnified colonoscopic findings. This study examined 118 lesions excised in our hospital as suspected serrated lesions after magnified observation between January 2008 and September 2011. Patient characteristics (sex, age), conventional colonoscopic findings (location, size, morphology, color, mucin) and magnified colonoscopic findings (pit pattern diagnosis) were interpreted by five colonoscopists with experience in over 1000 colonoscopies, and were compared with histopathological diagnoses. The pit patterns were categorized according to Kudo's classification, but a more detailed investigation was also performed using the subclassification [type II-Open (type II-O), type II-Long (type II-L), or type IV-Serrated (type IV-S)] proposed by Kimura T and Yamano H.

RESULTS

Lesions comprised 23 HPs (23/118: 19.5%), 39 TSAs (39/118: 33.1%: with cancer in one case), 50 SSA/Ps (50/118: 42.4%: complicated with cancer in three cases), and six others (6/118: 5.1%). We excluded six others, including three regular adenomas, one hamartoma, one inflammatory polyp, and one juvenile polyp for further analysis. Conventional colonoscopy showed that SSA/Ps were characterized as larger in diameter than TSAs and HPs (SSA/P vs HP, 13.62 ± 8.62 mm vs 7.74 ± 3.24 mm, P < 0.001; SSA/Ps vs TSA, 13.62 ± 8.62 mm vs 9.89 ± 5.73 mm, P < 0.01); common in the right side of the colon [HPs, 30.4% (7/23): TSAs, 20.5% (8/39): SSA/P, 84.0% (42/50), P < 0.001]; flat-elevated lesion [HPs, 30.4% (7/23): TSAs, 5.1% (2/39): SSA/Ps, 90.0% (45/50), P < 0.001]; normal-colored or pale imucosa [HPs, 34.8% (8/23): TSAs, 10.3% (4/39): SSA/Ps, 80% (40/50), P < 0.001]; and with large amounts of mucin [HPs, 21.7% (5/23): TSAs, 17.9% (7/39): SSA/Ps, 72.0% (36/50), P < 0.001]. In magnified colonoscopic findings, 17 lesions showed either type II pit pattern alone or partial type II pit pattern as the basic architecture, with 14 HPs (14/17, 70.0%) and 3 SSA/Ps. Magnified colonoscopy showed the type II-O pit pattern as characteristic of SSA/Ps [sensitivity 83.7% (41/49), specificity 85.7% (54/63)]. Cancer was also present in three lesions, in all of which a type VI pit pattern was also present within the same lesion. There were four HPs and four TSAs each. The type IV-S pit pattern was characteristic of TSAs [sensitivity 96.7% (30/31), specificity 89.9% (72/81)]. Cancer was present in one lesion, in which a type VI pit pattern was also present within the same lesion. In our study, serrated lesions of the colorectum also possessed the features described in previous reports of conventional colonoscopic findings. The pit pattern diagnosis using magnifying colonoscopy, particularly magnified colonoscopic findings using subclassifications of surface architecture, reflected the pathological characteristics of SSA/Ps and TSAs, and will be useful for colonoscopic diagnosis.

CONCLUSION

We suggest that this system could be a good diagnostic tool for SSA/Ps using magnifying colonoscopy.