Randomized comparison of surveillance intervals after colonoscopic removal of newly diagnosed adenomatous polyps. The National Polyp Study Workgroup

Screening for Colorectal Cancer

Colorectal cancer remains the third leading cause of cancer death in the United States. Colorectal cancer screening allows for prevention and early detection of precancerous and cancerous lesions, and screening has been shown to be effective in preventing colorectal cancer deaths. Screening recommendations vary by patient risk profile. A variety of screening modalities exist.

Adenoma characteristics in the English Bowel Cancer Screening Programme

AIM

The English Bowel Cancer Screening Programme detects colorectal cancers and premalignant polyps in a faecal occult blood test-positive population. The aim of this work is to describe the detection rates and characteristics of adenomas within the programme, identify predictive factors influencing the presence or absence of carcinoma within adenomas and identify the factors predicting the presence of advanced colonic neoplasia in different colon segments.

METHOD

The Bowel Cancer Screening System was retrospectively searched for polyps detected during colonoscopies between June 2006 and June 2012, at which time a guaiac test was being used. Data on size, location and histological features were collected, and described. Univariate and multivariate analyses were used to determine the significant factors influencing the development of carcinoma within an adenoma.

RESULTS

A total of 229 419 polyps were identified; after exclusions 136 973 adenomas from 58 334 patients were evaluated. Over half were in the rectum or sigmoid colon. Subcentimetre adenomas accounted for 69.8% of the total. The proportion of adenomas containing advanced histological features increased with increasing adenoma size up to 35 mm, then plateaued. A focus of carcinoma was found in 2282 (1.7%) adenomas, of which 95.6% were located distally. Carcinoma was identified even in diminutive adenomas (0.1%). The proportion of adenomas containing cancer was significantly higher in women than men (2.0% vs. 1.5%, p < 0.001).

CONCLUSION

This national, prospectively captured dataset adds robust information about histological features of adenomas that convey an increased risk for colorectal cancer, and identifies caecal adenomas, high-grade dysplasia, increasing adenoma size, distal location and female sex as independent risk factors associated with carcinoma.

Projected Colorectal Cancer Incidence and Mortality Based on Observed Adherence to Colonoscopy and Sequential Stool-Based Screening

INTRODUCTION

Modeling supporting recommendations for colonoscopy and stool-based colorectal cancer (CRC) screening tests assumes 100% sequential participant adherence. The impact of observed adherence on the long-term effectiveness of screening is unknown. We evaluated the effectiveness of a program of screening colonoscopy every 10 years vs annual high-sensitivity guaiac-based fecal occult blood testing (HSgFOBT) using observed sequential adherence data.

METHODS

The MIcrosimulation SCreening ANalysis (MISCAN) model used observed sequential screening adherence, HSgFOBT positivity, and diagnostic colonoscopy adherence in HSgFOBT-positive individuals from the National Colonoscopy Study (single-screening colonoscopy vs ≥4 HSgFOBT sequential rounds). We compared CRC incidence and mortality over 15 years with no screening or 10 yearly screening colonoscopy vs annual HSgFOBT with 100% and differential observed adherence from the trial.

RESULTS

Without screening, simulated incidence and mortality over 15 years were 20.9 (95% probability interval 15.8-26.9) and 6.9 (5.0-9.2) per 1,000 participants, respectively. In the case of 100% adherence, only screening colonoscopy was predicted to result in lower incidence; however, both tests lowered simulated mortality to a similar level (2.1 [1.6-2.9] for screening colonoscopy and 2.5 [1.8-3.4] for HSgFOBT). Observed adherence for screening colonoscopy (83.6%) was higher than observed sequential HSgFOBT adherence (73.1% first round; 49.1% by round 4), resulting in lower simulated incidence and mortality for screening colonoscopy (14.4 [10.8-18.5] and 2.9 [2.1-3.9], respectively) than HSgFOBT (20.8 [15.8-28.1] and 3.9 [2.9-5.4], respectively), despite a 91% adherence to diagnostic colonoscopy with FOBT positivity. The relative risk of CRC mortality for screening colonoscopy vs HSgFOBT was 0.75 (95% probability interval 0.68-0.80). Findings were similar in sensitivity analyses with alternative assumptions for repeat colonoscopy, test performance, risk, age, and projection horizon.

DISCUSSION

Where sequential adherence to stool-based screening is suboptimal and colonoscopy is accessible and acceptable-as observed in the national colonoscopy study, microsimulation, comparative effectiveness, screening recommendations.

An algorithm-based active cleansing protocol can reduce the bowel preparation time for screening colonoscopy: A propensity score matching study

BACKGROUND

Methods that minimize the time for on-site bowel preparation before colonoscopy are needed. We prospectively validated that a novel algorithm-based active cleansing (ABAC) protocol could reduce the time for preparation compared with the conventional method.

METHODS

This was an open-label, multicenter, prospective comparative study from April to October 2021. The study compared the bowel preparation time for colonoscopy between patients instructed with the ABAC protocol and control groups. Patients in the ABAC protocol group as well as the control group were administered 2000 mL of polyethylene glycol (PEG) within 2 hours. After the first two hours, patients in the protocol group voluntarily took 300 ml of the solution without the instruction of nursing staff depending on the number of defecations in the first 2 hours. The intervention and control groups were adjusted for background characteristics by propensity score matching (PSM).

RESULTS

After adjustment by PSM, 174 patients in each of the two groups were included in the final analysis. In the intention-to-treat analysis, the preparation time was significantly shorter in the intervention group than that in the control group (126.3 ± 32.7 min vs. 144.9 ± 39.9 min, P = 0.018). The proportion of additional PEG intake was significantly higher in the intervention group (16 [9.2%] vs. 6 [3.4%], P = 0.047). The number of defecations was also higher in the intervention group than in the control group (7.8 ± 2.5 vs. 6.3 ± 2.2, P = 0.001).

CONCLUSIONS

Simple active instruction protocol is effective to reduce on-site bowel preparation time and nursing staff labor for colonoscopy.

Recurrence rates of advanced colorectal neoplasia (ACN) in subjects with baseline ACN followed up at different surveillance intervals

BACKGROUND

Current clinical guidelines recommend that a baseline finding of advanced colorectal neoplasia (ACN) should be followed-up within 1-3 years.

AIM

We compared the recurrence rate of ACN at 1 year vs. 3 years among individuals with ACN detected and polypectomised at baseline colonoscopy.

METHODS

We extracted data from eligible patients in a Chinese population database from 2008 to 2018. The outcome variables included recurrence of advanced adenoma and advanced neoplasia, respectively, at follow-up colonoscopy. Binary logistic regression modeling was constructed to examine the association between length of surveillance and the outcome variables, controlling for risk factors of colorectal cancer, including age, gender, smoking, alcohol drinking, body mass index and chronic diseases.

RESULTS

We included 147,270 subjects who have received a baseline colonoscopy from our dataset. They were aged 69.3 years and 59.7% of them were male subjects. The crude 1-year and 3-year recurrence rate of ACN was 7.57% and 7.74%. From a binary logistic regression model, individuals with surveillance colonoscopy performed at 3 years did not have significantly higher recurrence rate of ACN than those followed-up at 1 year.

CONCLUSIONS

No statistically significantly difference in recurrence of ACN between individuals who received workup at 1vs. 3 years. These findings support a 3-year surveillance period after baseline ACN was polypectomised.

Dietary restriction after cold snare polypectomy of colorectal polyp for prevention of delayed bleeding

Background and Aim

Cold snare polypectomy (CSP) for small colorectal polyps is a safe technique; however, there is little evidence on whether dietary restriction after CSP is essential. This study aimed to determine whether dietary restriction after CSP is necessary to prevent delayed bleeding.

Methods

This is a randomized, controlled, non-inferiority trial conducted between November 2021 and March 2022. Patients with non-pedunculated small colorectal polyps (<10 mm) and who did not take anticoagulants were randomly allocated to two groups: (i) the normal diet (ND) group, and (ii) the low-residue diet (LRD) group. The ND group was instructed to eat anything after CSP, whereas the LRD group was advised to take LRD for 3 days after CSP. The primary endpoint was the occurrence of delayed major bleeding that needed endoscopic hemostasis.

Results

A total of 193 patients (average 57.5 years old, 51.9% male) were enrolled in the study. Subsequently, 97 and 96 patients were allocated to the ND and LRD group, respectively. The occurrence of delayed major bleeding was 1.0% in the ND group and 2.1% in the LRD group (95% confidence interval [CI]: -4.4% to 2.4%; difference: -1.1%), which showed the non-inferiority of the ND group. In addition, there was no difference between the two groups with respect to the occurrence of minor delayed bleeding (3.1% and 4.2%, respectively; difference: -1.1% [95% CI: -6.4% to 4.2%]).

Conclusion

Dietary restriction after CSP for low-bleeding-risk colorectal polyps is not necessary for the prevention of delayed bleeding (Registration number: UMIN000045669).

Surveillance after colorectal polyp resection

Post-polypectomy surveillance has proven to reduce colorectal cancer (CRC) incidence in patients with high-risk polyps, but it implies a major burden on colonoscopy units. Therefore, it should be targeted to individuals with a higher risk. Different societies have published guidelines on surveillance after resection of polyps, with notable discrepancies among them, and many recommendations come from low-quality evidence based on surrogate measures, such as risk of advanced adenoma, and not CRC risk. In this review, we aimed to summarize the evidence supporting post-polypectomy surveillance, compare the recently updated major guidelines, and discuss the existing discrepancies on this topic. Briefly, patients with adenomas ≥10 mm or high-grade dysplasia and patients with serrated polyps ≥10 mm or dysplasia are generally considered to have an increased risk of metachronous CRC and require surveillance, whereas the indication of surveillance is not clearly established in patients without these high-risk features.

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.

Utility of narrow-band imaging with or without dual focus magnification in neoplastic prediction of small colorectal polyps: a Vietnamese experience

BACKGROUND/AIMS

Accurate neoplastic prediction can significantly decrease costs associated with pathology and unnecessary colorectal polypectomies. Narrow band imaging (NBI) and dual-focus (DF) mode are promising emerging optical technologies for recognizing neoplastic features of colorectal polyps digitally. This study aimed to clarify the clinical usefulness of NBI with and without DF assistance in the neoplastic prediction of small colorectal polyps (<10 mm).

METHODS

This cross-sectional study included 530 small colorectal polyps from 343 consecutive patients who underwent colonoscopy at the University Medical Center from September 2020 to May 2021. Each polyp was endoscopically diagnosed in three successive steps using white-light endoscopy (WLE), NBI, and NBI-DF and retrieved for histopathological assessment. The diagnostic accuracy of each modality was evaluated with reference to histopathology.

RESULTS

There were 295 neoplastic polyps and 235 non-neoplastic polyps. The overall accuracies of WLE, WLE+NBI, and WLE+NBI+NBI-DF in the neoplastic prediction of colorectal polyps were 70.8%, 87.4%, and 90.8%, respectively (p<0.001). The accuracy of WLE+NBI+NBI-DF was significantly higher than that of WLE+NBI in the polyp size ≤5 mm subgroup (87.3% vs. 90.1%, p<0.001).

CONCLUSION

NBI improved the real-time neoplastic prediction of small colorectal polyps. The DF mode was especially useful in polyps ≤5 mm in size.

Safety of Cold Snare Polypectomy during Continuous Use of Antithrombotic Drugs for Delayed Post-Polypectomy Bleeding: A Pilot Study

BACKGROUND

Cold snare polypectomy is a high-risk endoscopic procedure with a low delayed post-polypectomy bleeding rate. However, it is unclear whether delayed post-polypectomy bleeding rates increase during continuous antithrombotic treatment. This study aimed to determine the safety of cold snare polypectomy during continuous antithrombotic treatment.

METHODS

This single-center, retrospective cohort study enrolled patients who underwent cold snare polypectomy during antithrombotic treatment between January 2015 and December 2021. Patients were divided into continuation and withdrawal groups based on whether they continued with antithrombotic drugs or not. Propensity score matching was performed using age, sex, Charlson comorbidity index, hospitalization, scheduled treatment, type of antithrombotic drugs used, multiple medications used, indication for antithrombotic drugs, and gastrointestinal endoscopist qualifications. The delayed polypectomy bleeding rates were compared between the groups. Delayed polypectomy bleeding was defined as the presence of blood in stools and requiring endoscopic treatment or a decrease in hemoglobin level by 2 g/dL or more.

RESULTS

The continuation and withdrawal groups included 134 and 294 patients, respectively. Delayed polypectomy bleeding was observed in 2 patients (1.5%) and 1 patient (0.3%) in the continuation and withdrawal groups, respectively (p = 0.23), before propensity score matching, with no significant difference. After propensity score matching, delayed polypectomy bleeding was observed in 1 patient (0.9%) in the continuation group but not in the withdrawal group, with no significant difference.

CONCLUSION

Cold snare polypectomy during continuous antithrombotic treatment did not significantly increase delayed post-polypectomy bleeding rates. Therefore, this procedure may be safe during continuous antithrombotic treatment.

Risk of Metachronous Neoplasia with High-Risk Adenoma and Synchronous Sessile Serrated Adenoma: A Systematic Review and Meta-Analysis

Background: Sessile serrated adenomas are important precursors to colorectal cancers and account for 30% of colorectal cancers. The United States Multi-Society Task Force recommends that patients with sessile serrated adenomas undergo surveillance similar to tubular adenomas. However, the risk of metachronous neoplasia when the high-risk adenoma co-exists with sessile serrated adenomas is poorly defined. Objective: To examine the risk of metachronous neoplasia in the presence of high-risk adenoma and synchronous sessile serrated adenomas compared with isolated high-risk adenoma. Data sources: PubMed, Embase, Scopus, Cochrane Library. Study selection: A literature search for studies evaluating the risk of metachronous neoplasia in patients with high-risk adenoma alone and those with synchronous high-risk adenoma and sessile serrated adenomas during surveillance colonoscopy was conducted on online databases. Main outcome measures: The primary outcome of interest was the presence of metachronous neoplasia. Results: Of the 1164 records reviewed, six (four retrospective and two prospective) studies met inclusion criteria with 2490 patients (1607 males, mean age 59.98 ± 3.23 years). Average follow-up was 47.5 ± 12.5 months. There were 2068 patients with high-risk adenoma on index colonoscopy and 422 patients with high-risk adenoma and synchronous sessile serrated adenomas. Pooled estimates showed a significantly elevated risk for metachronous neoplasia in patients with high-risk adenoma and synchronous sessile serrated adenomas (pooled odds ratio 2.21; 95% confidence intervals 1.65-2.96; p < 0.01). There was low heterogeneity (I² = 11%) among the studies. Sensitivity analysis of the prospective studies alone also showed elevated risk of metachronous neoplasm (pooled odds ratio 2.56; 95%, confidence intervals 1.05-6.23; p = 0.04). Limitations: Inclusion of a small number of retrospective studies. Conclusions: The presence of high-risk adenomas and synchronous sessile serrated adenomas is associated with an increased risk of metachronous neoplasia. Therefore, shorter surveillance intervals may be considered in patients with high-risk adenoma and synchronous sessile serrated adenomas compared to those with high-risk adenoma alone.

Rectal Cancer following Local Excision of Rectal Adenomas with Low-Grade Dysplasia-A Multicenter Study

Purpose: Rectal polyps with low-grade dysplasia (LGD) can be removed by local excision surgery (LE). It is unclear whether these lesions pose a higher risk for recurrence and cancer development and might warrant an early repeat rectal endoscopy. This study aims to assess the rectal cancer rate following local excision of LGD rectal lesions. Methods: A retrospective multicenter study including all patients that underwent LE for rectal polyps over a period of 11 years was conducted. Demographic, clinical, and surgical data of patients with LGD werecollected and analyzed. Results: Out of 274 patients that underwent LE of rectal lesions, 81 (30%) had a pathology of LGD. The mean patient age was 65 ± 11 years, and 52 (64%) were male. The mean distance from the anal verge was 7.2 ± 4.3 cm, and the average lesion was 3.2 ± 1.8 cm. Full thickness resection was achieved in 68 patients (84%), and four (5%) had involved margins for LGD. Nine patients (11%) had local recurrence and developed rectal cancer in an average time interval of 19.3 ± 14.5 months, with seven of them (78%) diagnosed less than two years after the initial LE. Seven of the nine patients were treated with another local excision, whilst one had a low anterior resection, and one was treated with radiation. The mean follow-up time was 25.3 ± 22.4 months. Conclusions: Locally resected rectal polyps with LGD may carry a significant risk of recurring and developing cancer within two years. This data suggests patients should have a closer surveillance protocol in place.

Risk of Metachronous Advanced Colorectal Neoplasia After Removal of Diminutive Versus Small Nonadvanced Adenomas: A Multicenter Study

BACKGROUND

Current postpolypectomy guidelines treat 1-9 mm nonadvanced adenomas (NAAs) as carrying the same level of risk for metachronous advanced colorectal neoplasia (ACRN).

AIMS

To evaluate whether small (6-9 mm) NAAs are associated with a greater risk of metachronous ACRN than diminutive (1-5 mm) NAAs.

METHODS

We retrospectively evaluated 10,060 index colonoscopies performed from July 2011 to June 2019. A total of 1369 patients aged ≥ 40 years with index NAAs and having follow-up examinations were categorized into 5 groups based on size and number of index findings: Group 1, ≤ 2 diminutive NAAs (n = 655); Group 2, ≤ 2 small NAAs (n = 529); Group 3, 3-4 diminutive NAAs (n = 78); Group 4, 3-4 small NAAs (n = 65); and Group 5, 5-10 NAAs (n = 42). Size was classified based on the largest NAA. ACRN was defined as finding an advanced adenoma or colorectal cancer at follow-up.

RESULTS

The absolute risk of metachronous ACRN increased from 7.2% in patients with all diminutive NAAs to 12.2% in patients with at least 1 small NAA (P = 0.002). Patients in Group 2 (adjusted odds ratio [AOR] 1.89; 95% confidence interval [CI], 1.21-2.95), Group 3 (AOR 2.40; 95% CI 1.78-4.90), Group 4 (AOR 2.77; 95% CI 1.35-5.66), and Group 5 (AOR 3.71; 95% CI 1.65-8.37) were associated with an increased risk of metachronous ACRN compared with Group 1.

CONCLUSIONS

Patients with small NAAs have an increased risk of metachronous ACRN. Postpolypectomy guidelines should consider including risk stratification between small and diminutive adenomas.

Ball Valve Syndrome is caused by Colon Polyp

BACKGROUND: Intestinal obstruction caused by ball valve syndrome, is a potentially lethal pathology. This case report will show ball valve syndrome in the large intestine (mechanical obstruction) and endoscopic treatment. CASE PRESENTATION: Our patient presented with abdominal pain and with intestinal obstruction-ileus. After colonoscopic examination was noticed, a large precancerous pedunculated polyp obstructed of large intestine due to ball valve effect. Mechanical obstruction was removed with endoscopic polypectomy. CONCLUSION: Endoscopic polypectomy must first be performed and if does not succeed, then indicated surgical interventions.

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

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

Cost Effectiveness of Mailed Outreach Programs for Colorectal Cancer Screening: Analysis of a Pragmatic, Randomized Trial

BACKGROUND & AIMS

Clinical guidelines for colorectal cancer (CRC) screening suggest use of either stool-based tests or colonoscopy - modalities that differ in recommended screening intervals, adherence, and costs. We know little about the long-term cost differences in population-health outreach strategies to promote these strategies.

METHODS

We conducted a cost-effectiveness analysis to compare 2 mailed outreach strategies to increase CRC screening from a pragmatic, randomized clinical trial: mailed fecal immunochemical test (FIT) kits vs invitations to complete a screening colonoscopy. We built a 10-year Markov chain Monte Carlo microsimulation model to account for differences in screening intervals, adherence, and costs.

RESULTS

Mailed FIT kits had a lower 10-year average per-person cost of screening relative to colonoscopy invitations ($1139 vs $1725) but with 10.89 fewer months of compliance and 60 fewer advanced neoplasia detected (37 advanced adenomas and 23 CRC). Incremental cost effectiveness ratios for colonoscopy invitations compared with mailed FIT kits were $55.23, $15.84, and $25.48 per additional covered month, advanced adenoma, and CRC, respectively. Although FIT was the preferred strategy at low willingness-to-pay thresholds, the 2 strategies were equal at a willingness-to-pay threshold of $41.31 per covered month gained.

CONCLUSION

Mailed FIT or colonoscopy invitations are both options to improve CRC screening completion and advanced neoplasia detection, and the choice of outreach strategy may differ by a health system's willingness-to-pay threshold. Mailed FIT kits are less expensive than colonoscopy invitations but result in fewer months of screening compliance and advanced neoplasia detected.

Indication of emergency colonoscopy after colorectal endoscopic submucosal dissection: A proposal of hematochezia scale

BACKGROUND AND AIM

Hematochezia is a major adverse event associated with colorectal endoscopic submucosal dissection (ESD). This study aimed to distinguish between hematochezia that required endoscopic hemostasis and hematochezia that required no hemostasis.

METHODS

This retrospective study included consecutive patients who underwent ESD for colorectal tumors at the Osaka International Cancer Institute between September 2017 and August 2020. The exclusion criteria were as follows: patients with coexisting advanced colorectal cancers or inflammatory bowel diseases, patients who received incomplete ESD or emergency surgery, or patients who underwent ESD for multiple lesions. We evaluated whether the patients had hematochezia and underwent emergency colonoscopy and hemostasis during hospitalization. The degree of hematochezia in the saved photographs was assessed using the hematochezia scale and classified as mild, moderate, or severe. Blood pressure, heart rate, time from ESD to first hematochezia, and total number of hematochezia episodes were also evaluated.

RESULTS

Among the 437 patients who underwent ESD, 44 were excluded, and 393 patients were evaluated. Hematochezia was observed in 100 patients (25%). Emergency colonoscopy was performed in 12 patients (3%), and hemostasis was required in six patients (2%). For patients with hematochezia, only mild hematochezia and hematochezia that developed ≤ 48 h after ESD were significantly associated with no intervention for hemostasis. The positive predictive value for no intervention for hemostasis was 100% (93-100%) for mild hematochezia and 98% (93-100%) for hematochezia ≤ 48 h.

CONCLUSIONS

Mild hematochezia and hematochezia ≤ 48 h were negative predictors of hemostasis, in which emergency colonoscopy may be avoided.

Comparison of procedural outcomes between morning and afternoon colonoscopies performed by colorectal surgeons

BACKGROUND AND OBJECTIVE

Colonoscopy is a common procedure performed by colorectal surgeons for screening, diagnosis, and surveillance of various colorectal diseases. Existing literature has conflicting data on quality outcomes of colonoscopies performed in the afternoon and the morning schedules and only includes colonoscopies performed by gastroenterologists. We sought to analyze procedural outcomes between morning and afternoon colonoscopies performed by colorectal surgeons.

DATA SOURCES AND MAIN OUTCOME MEASURES

A retrospective chart review of colonoscopies performed by colorectal surgeons at a tertiary care center from October 2018 through July 2020 was performed. Complete colonoscopies with documented times were included. Patients with colonic resection and incomplete colonoscopy were excluded. Main outcome measures adenoma and polyp detection rates and colonoscopy time variables were compared between morning and afternoon colonoscopies.

RESULTS

A total of 781 patients were analyzed. Colonoscopies were evenly distributed during shifts (49% morning and 51% afternoon). The overall polyp and adenoma detection rates were 46% and 29%, respectively. There were no significant differences in adenoma and polyp detection rates and colonoscopy duration between morning and afternoon colonoscopies. Multivariate analysis demonstrated that history of prior polypectomy was an independent predictor of adenoma detection rate (OR: 2.17, 95% CI 1.33-3.54, p = 0.002) and was associated with significantly increased colonoscopy times in afternoon shift.

CONCLUSION

There were no differences in quality outcomes of adenoma and polyp detection rates between morning and afternoon colonoscopies performed by colorectal surgeons. In addition to known predictors, cecal intubation time and history of polypectomy were also independent predictors of adenoma detection rate. Patients with prior polypectomy had increased colonoscopy times in afternoon shift. Since colorectal surgeons perform higher proportion of diagnostic and surveillance colonoscopies, these patients may be better suited for colonoscopies in morning shift.

Risk Factors of Delayed Bleeding After Cold Snare Polypectomy for Colorectal Polyps: A Multicenter Study

BACKGROUND

Delayed bleeding (DB) rarely occurs after cold snare polypectomy (CSP) for colorectal polyps, but no large-scale studies have investigated this. The present study evaluated the rate, characteristics, and risk factors of DB of CSP.

METHODS

We conducted a multicenter retrospective study at 10 Japanese institutions. A total of 18,007 patients underwent CSP for colorectal polyps ≤ 10 mm in size from March 2015 to September 2019, and cases of DB (DB group) were analyzed for the rate, antithrombotic drugs, polyp size, morphology, location, and risk factors. As a control, 269 non-bleeding cases (non-DB group) with 606 polyps who underwent CSP at the same 10 facilities in the 2-week study period were extracted.

RESULTS

We analyzed 26 DB cases with 28 lesions, and the total DB rate was 0.14% (26/18,007). The DB group had significantly higher rates of using antiplatelets (42.3% vs. 13.0%, p < 0.001) and anticoagulants (19.2% vs. 2.6%, p = 0.002), and significantly higher rates of polyp size ≥ 5 mm (67.9% vs. 45.2%, p = 0.015), rectal lesion (25.0% vs. 6.6%, p = 0.003), and polypoid lesion (89.3% vs. 55.3%, p < 0.001) than the non-DB group. A multivariate analysis (odds ratio; 95% confidence interval) for patient characteristics showed antiplatelet use (4.521; 1.817-11.249, p = 0.001) and anticoagulant use (7.866; 20.63-29.988, p = 0.003) as independent risk factors for DB. Polyp size ≥ 5 mm (3.251; 1.417-7.463, p = 0.005), rectal lesion (3.674; 1.426-9.465, p = 0.007), and polypoid lesion (7.087; 20.81-24.132, p = 0.002) were also risk factors for lesion characteristics.

CONCLUSIONS

The rate of DB was 0.14% and antithrombotic drug use, polyp size, location, and morphology were related to it.

Coupé VM. A progressive three-state model to estimate time to cancer: a likelihood-based approach

Background

To optimize colorectal cancer (CRC) screening and surveillance, information regarding the time-dependent risk of advanced adenomas (AA) to develop into CRC is crucial. However, since AA are removed after diagnosis, the time from AA to CRC cannot be observed in an ethically acceptable manner. We propose a statistical method to indirectly infer this time in a progressive three-state disease model using surveillance data.

Methods

Sixteen models were specified, with and without covariates. Parameters of the parametric time-to-event distributions from the adenoma-free state (AF) to AA and from AA to CRC were estimated simultaneously, by maximizing the likelihood function. Model performance was assessed via simulation. The methodology was applied to a random sample of 878 individuals from a Norwegian adenoma cohort.

Results

Estimates of the parameters of the time distributions are consistent and the 95% confidence intervals (CIs) have good coverage. For the Norwegian sample (AF: 78%, AA: 20%, CRC: 2%), a Weibull model for both transition times was selected as the final model based on information criteria. The mean time among those who have made the transition to CRC since AA onset within 50 years was estimated to be 4.80 years (95% CI: 0; 7.61). The 5-year and 10-year cumulative incidence of CRC from AA was 13.8% (95% CI: 7.8%;23.8%) and 15.4% (95% CI: 8.2%;34.0%), respectively.

Conclusions

The time-dependent risk from AA to CRC is crucial to explain differences in the outcomes of microsimulation models used for the optimization of CRC prevention. Our method allows for improving models by the inclusion of data-driven time distributions.

Supplementary Information

The online version contains supplementary material available at (10.1186/s12874-022-01645-2).

Green Tea Extract to Prevent Colorectal Adenomas, Results of a Randomized, Placebo-Controlled Clinical Trial

INTRODUCTION

Preclinical, epidemiological, and small clinical studies suggest that green tea extract (GTE) and its major active component epigallocatechingallate (EGCG) exhibit antineoplastic effects in the colorectum.

METHODS

A randomized, double-blind trial of GTE standardized to 150 mg of EGCG b.i.d. vs placebo over 3 years was conducted to prevent colorectal adenomas (n = 1,001 with colon adenomas enrolled, 40 German centers). Randomization (1:1, n = 879) was performed after a 4-week run-in with GTE for safety assessment. The primary end point was the presence of adenoma/colorectal cancer at the follow-up colonoscopy 3 years after randomization.

RESULTS

The safety profile of GTE was favorable with no major differences in adverse events between the 2 well-balanced groups. Adenoma rate in the modified intention-to-treat set (all randomized participants [intention-to-treat population] and a follow-up colonoscopy 26-44 months after randomization; n = 632) was 55.7% in the placebo and 51.1% in the GTE groups. This 4.6% difference was not statistically significant (adjusted relative risk 0.905; P = 0.1613). The respective figures for the per-protocol population were 54.3% (151/278) in the placebo group and 48.3% (129/267) in the GTE group, indicating a slightly lower adenoma rate in the GTE group, which was not significant (adjusted relative risk 0.883; P = 0.1169).

DISCUSSION

GTE was well tolerated, but there was no statistically significant difference in the adenoma rate between the GTE and the placebo groups in the whole study population.

Colonoscopy surveillance following adenoma removal to reduce the risk of colorectal cancer: a retrospective cohort study

BACKGROUND

Colonoscopy surveillance is recommended for some patients post polypectomy. The 2002 UK surveillance guidelines classify post-polypectomy patients into low, intermediate and high risk, and recommend different strategies for each classification. Limited evidence supports these guidelines.

OBJECTIVES

To examine, for each risk group, long-term colorectal cancer incidence by baseline characteristics and the number of surveillance visits; the effects of interval length on detection rates of advanced adenomas and colorectal cancer at first surveillance; and the cost-effectiveness of surveillance compared with no surveillance.

DESIGN

A retrospective cohort study and economic evaluation.

SETTING

Seventeen NHS hospitals.

PARTICIPANTS

Patients with a colonoscopy and at least one adenoma at baseline.

MAIN OUTCOME MEASURES

Long-term colorectal cancer incidence after baseline and detection rates of advanced adenomas and colorectal cancer at first surveillance.

DATA SOURCES

Hospital databases, NHS Digital, the Office for National Statistics, National Services Scotland and Public Health England.

METHODS

Cox regression was used to compare colorectal cancer incidence in the presence and absence of surveillance and to identify colorectal cancer risk factors. Risk factors were used to stratify risk groups into higher- and lower-risk subgroups. We examined detection rates of advanced adenomas and colorectal cancer at first surveillance by interval length. Cost-effectiveness of surveillance compared with no surveillance was evaluated in terms of incremental costs per colorectal cancer prevented and per quality-adjusted life-year gained.

RESULTS

Our study included 28,972 patients, of whom 14,401 (50%), 11,852 (41%) and 2719 (9%) were classed as low, intermediate and high risk, respectively. The median follow-up time was 9.3 years. Colorectal cancer incidence was 140, 221 and 366 per 100,000 person-years among low-, intermediate- and high-risk patients, respectively. Attendance at one surveillance visit was associated with reduced colorectal cancer incidence among low-, intermediate- and high-risk patients [hazard ratios were 0.56 (95% confidence interval 0.39 to 0.80), 0.59 (95% confidence interval 0.43 to 0.81) and 0.49 (95% confidence interval 0.29 to 0.82), respectively]. Compared with the general population, colorectal cancer incidence without surveillance was similar among low-risk patients and higher among high-risk patients [standardised incidence ratios were 0.86 (95% confidence interval 0.73 to 1.02) and 1.91 (95% confidence interval 1.39 to 2.56), respectively]. For intermediate-risk patients, standardised incidence ratios differed for the lower- (0.70, 95% confidence interval 0.48 to 0.99) and higher-risk (1.46, 95% confidence interval 1.19 to 1.78) subgroups. In each risk group, incremental costs per colorectal cancer prevented and per quality-adjusted life-year gained with surveillance were lower for the higher-risk subgroup than for the lower-risk subgroup. Incremental costs per quality-adjusted life-year gained were lowest for the higher-risk subgroup of high-risk patients at £7821.

LIMITATIONS

The observational design means that we cannot assume that surveillance caused the reductions in cancer incidence. The fact that some cancer staging data were missing places uncertainty on our cost-effectiveness estimates.

CONCLUSIONS

Surveillance was associated with reduced colorectal cancer incidence in all risk groups. However, in low-risk patients and the lower-risk subgroup of intermediate-risk patients, colorectal cancer incidence was no higher than in the general population without surveillance, indicating that surveillance might not be necessary. Surveillance was most cost-effective for the higher-risk subgroup of high-risk patients.

FUTURE WORK

Studies should examine the clinical effectiveness and cost-effectiveness of post-polypectomy surveillance without prior classification of patients into risk groups.

TRIAL REGISTRATION

This trial is registered as ISRCTN15213649.

FUNDING

This project was funded by the National Institute for Health and Care Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 26, No. 26. See the NIHR Journals Library website for further project information.

Difference in the prevalence of advanced colon adenoma between patients with gastric neoplasm and healthy people: A STROBE-compliant study

We compared the prevalence of adenoma and cancerous colon polyps in patients undergoing endoscopic removal or gastric surgery for gastric adenoma or gastric cancer and in healthy individuals.The medical records of 707 patients with gastric neoplasm and 798 age- and sex-matched healthy subjects were retrospectively analyzed between January 2010 and July 2018. The clinicopathological characteristics, prevalence of colorectal neoplasm diagnosed by colonoscopy, and risk factors for colorectal polyps were also investigated.When comparing the two groups, the prevalence of overall colorectal polyps and its distribution was not different between the two groups (54.0% vs.49.5%, P = .079), whereas, the number of colon polyps (1.20 ± 1.71 vs 0.99 ± 1.54, P = .015) and the maximal size (3.53 ± 6.14 vs 2.08 ± 2.88, P < .001) were significantly larger in the gastric neoplasm group. The prevalence of advanced colon adenoma was significantly higher in the gastric neoplasm group (10.7% vs 3.8%, P < .001). Risk factors such as elevated glucose levels and the presence of gastric neoplasm were related to the prevalence of all colon polyps. The presence of gastric neoplasm is an important risk factor for advanced colon polyps.Patients with gastric neoplasms had a significantly higher prevalence of advanced colon adenoma. Advanced colon adenoma is associated with the chain from benign adenomas through malignant altered adenomas to advanced colon cancer. Thus, patients with gastric neoplasm are regarded as a high-risk group for colorectal cancer and are recommended for screening colonoscopy at the time of diagnosis.

In silico identification of novel biomarkers for key players in transition from normal colon tissue to adenomatous polyps

Adenomatous polyps of the colon are the most common neoplastic polyps. Although most of adenomatous polyps do not show malign transformation, majority of colorectal carcinomas originate from neoplastic polyps. Therefore, understanding of this transformation process would help in both preventive therapies and evaluation of malignancy risks. This study uncovers alterations in gene expressions as potential biomarkers that are revealed by integration of several network-based approaches. In silico analysis performed on a unified microarray cohort, which is covering 150 normal colon and adenomatous polyp samples. Significant gene modules were obtained by a weighted gene co-expression network analysis. Gene modules with similar profiles were mapped to a colon tissue specific functional interaction network. Several clustering algorithms run on the colon-specific network and the most significant sub-modules between the clusters were identified. The biomarkers were selected by filtering differentially expressed genes which also involve in significant biological processes and pathways. Biomarkers were also validated on two independent datasets based on their differential gene expressions. To the best of our knowledge, such a cascaded network analysis pipeline was implemented for the first time on a large collection of normal colon and polyp samples. We identified significant increases in TLR4 and MSX1 expressions as well as decrease in chemokine profiles with mostly pro-tumoral activities. These biomarkers might appear as both preventive targets and biomarkers for risk evaluation. As a result, this research proposes novel molecular markers that might be alternative to endoscopic approaches for diagnosis of adenomatous polyps.

Post-polypectomy surveillance interval and advanced neoplasia detection rates: a multicenter, retrospective cohort study

BACKGROUND

Longer post-polypectomy surveillance intervals are associated with increased colorectal neoplasia detection at surveillance in some studies. We investigated this association to inform optimal surveillance intervals.

METHODS

Patients who underwent colonoscopy and post-polypectomy surveillance at 17 UK hospitals were classified as low/high risk by baseline findings. We compared detection rates of advanced adenomas (≥ 10 mm, tubulovillous/villous, high grade dysplasia), high risk findings (HRFs: ≥ 2 serrated polyps/[adenomas] of which ≥ 1 is ≥ 10 mm or has [high grade] dysplasia; ≥ 5 serrated polyps/adenomas; or ≥ 1 nonpedunculated polyp ≥ 20 mm), or colorectal cancer (CRC) at surveillance colonoscopy by surveillance interval (< 18 months, 2, 3, 4, 5, 6 years). Risk ratios (RRs) were estimated using multivariable regression.

RESULTS

Of 11 214 patients, 7216 (64 %) were low risk and 3998 (36 %) were high risk. Among low risk patients, advanced adenoma, HRF, and CRC detection rates at first surveillance were 7.8 %, 3.7 %, and 1.1 %, respectively. Advanced adenoma detection increased with increasing surveillance interval, reaching 9.8 % with a 6-year interval (P trend < 0.001). Among high risk patients, advanced adenoma, HRF, and CRC detection rates at first surveillance were 15.3 %, 10.0 %, and 1.5 %, respectively. Advanced adenoma and CRC detection rates (P trends < 0.001) increased with increasing surveillance interval; RRs (95 % confidence intervals) for CRC were 1.54 (0.68-3.48), 4.44 (1.95-10.08), and 5.80 (2.51-13.40) with 3-, 4-, and 5-year intervals, respectively, versus an interval of < 18 months.

CONCLUSIONS

Metachronous neoplasia was uncommon among low risk patients, even with long surveillance intervals, supporting recommendations for no surveillance in these patients. For high risk patients, a 3-year surveillance interval would ensure timely CRC detection.

Early-Onset Colorectal Cancer Is Associated with a Lower Risk of Metachronous Advanced Neoplasia than Traditional-Onset Colorectal Cancer

BACKGROUND

Colorectal cancer (CRC) incidence in the USA has increased in adults under age 50. Current CRC surveillance guidelines do not consider age at diagnosis, and there are limited data available on outcomes from surveillance colonoscopies in early-onset CRC (EO-CRC) to guide recommendations on surveillance intervals.

AIMS

To compare surveillance outcomes between EO-CRC and traditional-onset colorectal cancer (TO-CRC).

METHODS

In a retrospective cohort study in a large tertiary care academic medical center, we collected data on patients with a diagnosis of CRC between 2000 and 2014 who received surgery with curative intent. We used log-rank test and inverse probability of treatment weighted Cox regression analysis to compare the development of metachronous advanced neoplasia (MAN) in patients with EO-CRC (diagnosed ages 18-49) and TO-CRC (diagnosed ages 50-75).

RESULTS

Patients with EO-CRC (n = 107) were more likely to present with advanced-stage disease (62% versus 35%, p < 0.0001), rectal tumors (45% versus 27%, p < 0.01), and a family history of CRC (30% versus 16%, p = 0.02) compared to those with TO-CRC (n = 139). Patients with EO-CRC had lower risk of MAN (adjusted HR 0.44, 95% CI 0.22-0.88) than TO-CRC patients. The 5-year event rate for MAN was lower for patients with EO-CRC compared to patients with TO-CRC (5.8% vs. 16.1%, p = 0.07). The presence of synchronous neoplasia or history of diabetes was also predictive of MAN.

CONCLUSIONS

EO-CRC was independently associated with a lower risk of developing MAN compared to TO-CRC. Shorter surveillance intervals may not be warranted in EO-CRC; however, large prospective studies are needed.

An Evidence-Based Guideline for Surveillance of Patients after Curative Treatment for Colon and Rectal Cancer

Objective: To provide recommendations for a surveillance regimen that leads to the largest overall survival benefit for patients after curative treatment for Stage I–IV colon and rectal cancer. Methods: Consistent with the Program in Evidence-Based Care’s standard approach, guideline databases, i.e., MEDLINE, EMBASE, PubMed, Cochrane Library, and PROSPERO, were systematically searched. Then, we drafted recommendations and methodology experts performed an internal review of the resulting draft recommendations, which was followed by an external review by targeted experts and intended users. Results: Four systematic reviews and two randomized controlled trials were identified that provided evidence for recommendations. Conclusions: For patients with stage I–III colon cancer, a medical history and physical examination should be performed every six months for three years; computed tomography (CT) of the chest-abdomen-pelvis (CT CAP) should be performed at one and three years, or one CT CAP could be performed at 18 months; the use of carcinoembryonic antigen (CEA) is optional if CT imaging is being performed; and surveillance colonoscopy should be performed one year after the initial surgery. The frequency of subsequent surveillance colonoscopy should be dictated by previous findings, but generally, colonoscopies should be performed every five years if the findings are normal. There was insufficient evidence to support these recommendations for patients with rectal cancer, Stage IV colon cancer, and patients over the age of 75 years. Patients should be informed of current recommendations and the treating physician should discuss the specific risks and benefits of each recommendation with their patients.

Clinical outcome of non-curative endoscopic submucosal dissection for early colorectal cancer

OBJECTIVE

Endoscopic submucosal dissection (ESD) in a curative intent for submucosa-invasive early (T1) colorectal cancers (T1-CRCs) often leads to subsequent surgical resection in case of histologic parameters indicating higher risk of nodal involvement. In some cases, however, the expected benefit may be offset by the surgical risks, suggesting a more conservative approach.

DESIGN

Retrospective analysis of consecutive patients with T1-CRC who underwent ESD at 13 centres ending inclusion in 2019 (n=3373). Cases with high risk of nodal involvement (non-curative ESD: G3, submucosal invasion>1000 µm, lymphovascular involvement, budding or incomplete resection/R1) were analysed if follow-up data (endoscopy/imaging) were available, regardless of the postendoscopic management (follow-up vs surgery) selected by the multidisciplinary teams in these institutions. Comorbidities were classified according to Charlson Comorbidity Index (CCI). Outcomes were disease recurrence, death and disease-related death rates in the two groups. Rate of residual disease (RD) at both the previous resection site and regional lymph nodes was assessed in the surgical cases as well as from follow-up in the follow-up group.

RESULTS

Of 604 patients treated by colorectal ESD for submucosally invasive cancer, 207 non-curative resections (34.3%) were included (138 male; mean age 67.6±10.9 years); in 65.2% of cases, no complete resection was achieved (R1). Of the 207 cases, 60.9% (n=126; median CCI: 3; IQR: 2-4) underwent surgical treatment with RD in 19.8% (25/126), while 39.1% (n=81, median CCI: 5; IQR: 4-6) were followed up by endoscopy in all cases. Patients in the follow-up group had a higher overall mortality (HR=3.95) due to non-CRC causes (n=9, mean survival after ESD 23.7±13.7 months). During this follow-up time, tumour recurrence and disease-specific survival rates were not different between the groups (median follow-up 30 months; range: 6-105).

CONCLUSION

Following ESD for a lesion at high risk of RD, follow-up only may be a reasonable choice in patients at high risk for surgery. Also, endoscopic resection quality should be improved.

TRIAL REGISTRATION NUMBER

NCT03987828.

Post-polypectomy colonoscopy surveillance: Can we improve the diagnostic yield?

Although adenomas and serrated polyps are the preneoplastic lesions of colorectal cancer, only few of them will eventually progress to cancer. This review provides a comprehensive overview of the present and future of post-polypectomy colonoscopy surveillance. Post-polypectomy surveillance guidelines have recently been updated and all share the aim towards more selective and less frequent surveillance. We have examined these current guidelines and compared the recommendations of each of them. To improve the diagnostic yield of post-polypectomy surveillance it is important to find predictors of metachronous polyps that better identify high-risk individuals of developing advanced neoplasia. For this reason, we have also conducted a literature review of the molecular biomarkers of metachronous advanced colorectal polyps. Finally, we have discussed future directions of post-polypectomy surveillance and identified possible strategies to improve the use of endoscopic resources with the COVID-19 pandemic.

Long-term cumulative incidence of metachronous advanced colorectal neoplasia after colonoscopy and a novel risk factor: a cohort study

BACKGROUND AND AIM

Long-term cumulative incidence of and risk factors for metachronous advanced colorectal neoplasia, including both advanced colorectal adenoma (≥10 mm, or with villous or high-grade dysplasia) and colorectal cancer, are critical for surveillance strategies. The aim of this study was to determine the cumulative incidence of metachronous advanced colorectal neoplasia and its risk factors.

METHODS

A retrospective cohort study was conducted on 6720 consecutive individuals who underwent general health check-ups and colonoscopy. Colorectal adenomas at initial colonoscopy were categorized as low-risk (1-2 small [<10 mm] tubular adenomas) or high-risk adenoma (≥3 tubular adenomas of any size; at least one adenoma ≥10 mm; or villous adenoma or adenoma with high-grade dysplasia). Kaplan-Meier estimates and hazard ratio by Cox-proportional hazard regression were calculated.

RESULTS

The cumulative incidence (95% confidence interval [CI]) of metachronous advanced colorectal neoplasia at 5 and 10 years was 5.7% [4.6-7.1], and 11% [8.9-14] in the low-risk adenoma group, and 10% [8.6-13], and 17% [14-21] in high-risk adenoma group, respectively. Adjusted hazard ratio [95% CI] of low-risk adenoma (vs. no colorectal adenoma), high-risk adenoma (vs. no colorectal adenoma), current smoking and positive fecal immunochemical test were 1.34 [1.04-1.74], 1.94 [1.48-2.55], 1.55 [1.2-2.02] and 1.69 [1.35-2.1], respectively. Adjusted hazard ratio [95% CI] of positive fecal immunochemical test was 1.88 [1.29-2.74] in those with normal colonoscopy.

CONCLUSIONS

Both low-risk and high-risk adenomas confer substantial risk for metachronous advanced colorectal neoplasia at 10 years. Positive fecal immunochemical test was a significant risk factor for metachronous advanced colorectal neoplasia despite normal colonoscopy.

Early-Age Onset Colorectal Neoplasia in Average-Risk Individuals Undergoing Screening Colonoscopy: A Systematic Review and Meta-Analysis

BACKGROUND & AIMS

Incidence and mortality associated with early-age onset colorectal cancer (EAO-CRC) is increasing, prompting professional society recommendations to lower the screening age in average-risk individuals. The yield of screening individuals younger than 50 years is not known.

METHODS

A systematic review of 3 databases from inception through July 2020 was performed in all languages that reported colonoscopy findings in average-risk individuals younger than 50 years. The primary outcomes were EAO colorectal neoplasia (CRN) and advanced colorectal neoplasia (aCRN) prevalence. Subgroup analyses were performed based on sex, geographic location, time period, and age, including comparison with those aged 50-59 years. Generalized linear mixed model with random intercept logistic regression and fixed subgroup effects were performed.

RESULTS

Of 10,123 unique articles, 17 studies published between 2002 and 2020, including 51,811 average-risk individuals from 4 continents, were included. The pooled rate of EAO-CRN was 13.7% (95% confidence interval [CI], 0.112%-0.168%) and EAO-aCRN was 2.2% (95% CI, 0.016%-0.031%). Prevalence of CRC was 0.05% (95% CI, 0.00029%-0.0008%). Rates of EAO-CRN were higher in men compared with women (relative risk, 1.71%; 95% CI, 1.49%-1.98%), and highest in the United States (15.6%; 95% CI, 12.2%-19.7%) compared with Europe (14.9%; 95% CI, 6.9%-29.3%), East Asia (13.4%; 95% CI, 10.3%-17.2%), and the Middle East (9.8%; 95% CI, 7.8%-12.2%) (P = .04) The rate of EAO-CRN in age groups 45-49 years and 50-59 years was 17.8% (95% CI, 14.5%-21.6%) and 24.8% (95% CI, 19.5%-30.8%), respectively (P = .04). The rate of EAO-aCRN in age group 45-49 years was 3.6% (95% CI, 1.9%-6.7%) and 4.2% (95% CI, 3.2%-5.7%), respectively (P = .69).

CONCLUSIONS

The rate of aCRN in individuals aged 45-49 years was similar to the rate observed in individual aged 50-59 years, suggesting that expanding screening to this population could yield a similar impact on colorectal cancer risk reduction.

The necessity of intensive surveillance colonoscopy for patients with a remaining right colon after resection of colorectal cancer: a retrospective cohort study

PURPOSE

To clarify how often postoperative surveillance colonoscopy should be undertaken based on the risk factors for the development of metachronous cancer (MC) and advanced adenoma (AA) after surgery for colorectal cancer.

METHODS

We collected data of consecutive patients who underwent curative resection for primary colorectal cancer between 2005 and 2012, with preoperative colonoscopy and surveillance colonoscopy at 1 year after surgery (406 patients, mean age: 69 years, 59% male). The detection rates of AA (with villous features, > 10 mm or high-grade dysplasia) and MC by surveillance colonoscopy were the primary outcomes.

RESULTS

At 5 years, colonoscopy was performed as postoperative surveillance an average of 3.2 times. AA and MC were detected in 57 (14.0%) and 18 patients (4.4%), respectively. Both lesions were more common in the right colon (n = 43) than in the left colon (n = 28). The detection rate did not differ to a statistically significant extent according to the number of colonoscopies performed for surveillance (p = 0.21). However, after left-sided colectomy, both types of lesions were more commonly detected in those who received ≥ 3 colonoscopies than in those with one or two colonoscopies (p = 0.04).

CONCLUSION

A remaining right colon after left-sided colectomy was associated with a higher risk of developing AA and MC. Physicians should consider performing surveillance colonoscopy more frequently if the right colon remains after surgery.

Cost-effectiveness analysis of a community-based colorectal cancer screening program in Shanghai, China

OBJECTIVE

This study investigated the cost-effectiveness of a community-based colorectal cancer-screening program (C-CRCSP) in Shanghai, China, among the residents in the urban, suburban and rural areas.

METHODS

A Markov model was constructed to evaluate the cost-effectiveness of a 25-year annual C-CRCSP including 100 000 populations. Cost-effectiveness was determined by the incremental cost-effectiveness ratio (ICER); referring to either life-years gained, or quality-adjusted life-years (QALYs) gained. The threshold was gross domestic product per capita. Univariate and multivariate sensitivity analyses were performed to investigate the influence of compliance, prevalence, technological performance, medical cost and annual cost discount rate (3.5%) on ICER. A probabilistic sensitivity analysis evaluated the probability of the cost-effectiveness of C-CRCSP at different maximum acceptable ceiling ratios.

RESULTS

Compared with no screening, the C-CRCSP resulted in total gains of 7840 QALYs and 2210 life-years (LY), at a total cost of CNY 58.54 million; that is, the ICER were CNY 7460/QALYs and CNY 26650/LY. Stratifying by residency, the cumulative gains in QALYs and LY were estimated to be the lowest in the urban populations compared with the rural and suburban populations. The cost for the urban population was 3-fold and 6-fold that of the suburban and rural populations. The ICER for QALYs ranged from 2180 (rural) to 16 840 (urban).

CONCLUSION

The cost-effectiveness of a C-CRCSP in Shanghai was most favorable for the rural population, while the urban population benefits less in terms of QALYs. ICER could be enhanced by measures that increase compliance.

Resting heart rate is associated with colorectal advanced adenoma

Background and aims

Resting heart rate is an independent predictor of colorectal cancer (CRC) development and CRC-related mortality. However, little is known about the relationship between resting heart rate and colorectal adenoma development. We aimed to investigate this association in a population who underwent screening colonoscopy.

Methods

Among 39,021 patients who underwent both electrocardiogram and screening colonoscopy during routine health examinations at the Seoul National University Bundang Hospital, Health Promotion Center, Korea from January 2014 to July 2019, 1,344 patients had advanced adenoma. We performed 1:1 propensity score (PS) matching to establish a control group that mitigated the confounding effects of age and sex. We performed multivariate logistic regression analyses to identify the independent risk factors of advanced adenoma development.

Results

Resting heart rate was significantly higher in the advanced adenoma group than in the control group. The prevalence of advanced polyp increased across the quartiles of resting heart rate. Patients with higher resting heart rates were more likely to be older, smokers, and have increased blood pressure and DM and less likely to engage in active exercises than those with lower resting heart rates. Patients with higher resting heart rates had higher serum glucose, triglyceride, hemoglobin A1C, and insulin levels and lower high-density lipoprotein cholesterol levels. Patients with resting heart rate in the highest quartile (≥71 bpm) still showed significantly increased odds ratio (OR) of advanced adenoma development (OR: 1.379, 95% confidence interval: 1.099–1.731, p = 0.006).

Conclusions

High resting heart rate was a meaningful independent risk factor of advanced adenoma development.

The impact of 6 years of the National Colorectal Cancer Screening Program on colorectal cancer incidence and 5-year survival

We aimed to assess the impact of the first three rounds of the National Colorectal Cancer Screening Program (NCCSP) on CRC incidence and mortality in Slovenia. In NCCSP, we use two fecal immune tests (FITs) and if test is positive patient is referred to colonoscopy. From 2009, we invite Slovenian residents aged 50-69 years, one screening round takes 2 years. The response rate was from 56.9 to 59.9%. FIT was positive in 6.0-6.2% (more in older patients and in men; P < 0.05). The adenoma detection rate was >51.3% (more in men; P < 0.01). In NCCSP, 70.3% of all cancers diagnosed were in stages I and II, while 20.7% of all CRC were found in polyps resected during colonoscopies. Patients with positive first FIT have odds ratio 2.19 [95% confidence interval (CI), 2.06-2.32] for advanced neoplasia and cancer compared to patients with two negative FITs. The incidence rate for CRC has dropped significantly after 6 years in population and in men (P < 0.01) but not in women. Five-year CRC survival was 31.3% higher if cancer was diagnosed in NCCSP (P < 0.05). After 6 years of NCCSP, the incidence rate for CRC has dropped significantly (P < 0.01). Hazard ratio for death from CRC was 3.84 higher (95% CI, 3.36-4.40; P < 0.001) in patients with cancer detected outside the program.

Pre-administration of super-low volume polyethylene glycol is as effective as senna laxative as bowel preparation for colonoscopy: a randomized controlled phase 2 trial

BACKGROUND AND PURPOSE

Senna laxatives are commonly used for bowel preparation before colonoscopies in Japan. However, this laxative frequently causes complications such as abdominal pain. This study aimed to establish a novel method of bowel preparation, which involved the pre-administration of super-low volume polyethylene glycol (PEG) for three days followed by the same-day administration of low volume PEG.

METHODS

This study was a prospective, multicenter, investigator-blinded, phase 2, randomized control trial. The intake of 13.9 g (120 mL) of PEG or 1 g of a senna laxative for 3 days before the examination was indicated for each group, and 2 L of PEG solution was used for preparation on the examination day. The primary endpoint was the efficacy of bowel cleansing, as assessed by the Boston bowel preparation scale. The secondary endpoints were the adenoma detection rate and occurrence of complications.

RESULTS

A total of 250 patients were initially enrolled. A total of 122 patients from each group were included in the intention-to-treat analysis. In the intention-to-treat analysis, the responder rates were the same for the two groups (56.6% vs 50.8%). Additionally, the adenoma detection rate did not differ between the two groups (34.9% vs 41.8%, P = 0.3795). In contrast, adherence was higher in the PEG group (93.4% vs 82.8%, P = 0.0101), and the occurrence of complications was lower in the PEG group (1.7% vs 16.4%, P = 0.0001).

CONCLUSION

The novel super-low volume PEG method for bowel preparation was as effective as the conventional method with senna laxatives.

Colonoscopy screening and surveillance guidelines

The Colonoscopy Screening and Surveillance Guidelines were developed by the Japan Gastroenterological Endoscopy Society as basic guidelines based on the scientific methods. The importance of endoscopic screening and surveillance for both detection and post-treatment follow-up of colorectal cancer has been recognized as essential to reduce disease mortality. There is limited high-level evidence in this field; therefore, we had to focus on the consensus of experts. These clinical practice guidelines consist of 20 clinical questions and eight background knowledge topics that have been determined as the current guiding principles.

Value of combined detection of IFOBT, tumor markers, and inflammatory markers in predicting occurrence of advanced colorectal adenoma

BACKGROUND

At present, there is a lack of effective, non-invasive screening tests for colorectal precancerous lesions. Identification of high-risk groups and multi-biomarker detection have become the trend of cancer and precancerous lesion screening. Inflammatory markers have been widely used in the diagnosis and prognosis of various tumors, but there are few studies on their diagnostic value in precancerous lesions.

AIM

To explore the predictive value of the general characteristics, neutrophil to lymphocyte ratio (NLR), platelet to lymphocyte ratio (PLR), CEA, CA199, and immunochemical fecal occult blood testing (IFOBT) in the occurrence of advanced colorectal adenoma.

METHODS

Two hundred and ninety-five cases of advanced colorectal adenomas confirmed by pathology and electronic colonoscopy at our hospital from 2014 to 2018 were retrospectively analyzed, and 448 cases of non-advanced adenomas in the same period were selected as a control group. The general clinical data of the patients, including basic characteristics (gender and age), living habits (smoking and drinking), and past history of disease (hypertension, coronary heart disease, diabetes), history of surgery (history of cholecystectomy or appendectomy), and laboratory examinations (NLR, PLR, CEA, CA199, and IFOBT) were collected. Measurement data were compared using t-test or Mann-Whitney U test, and count data were compared using χ² test. Statistically significant variables were included in binary logistic regression analysis. ROC curve was drawn to evaluate the predictive value of related indexes in the occurrence of advanced colorectal adenoma.

RESULTS

Multivariate logistic regression analysis demonstrated that age (odds ratio [OR] = 1.047, 95% confidence interval [CI]: 1.028-1.066, P = 0.000), smoking (OR = 1.880, 95%CI: 1.250-2.826, P = 0.002), diabetes (OR = 2.073, 95CI%: 1.216-3.535, P=0.007), previous cholecystectomy (OR = 9.206, 95CI%: 2.904-29.181, P = 0.000), IFOBT (OR = 7.681, 95%CI: 4.585-12.869, P = 0.000), CA199 (OR = 1.039, 95%CI: 1.018-1.059, P = 0.000), and NLR (OR = 1.706, 95%CI: 1.388-2.097, P = 0.000) were independent factors for advanced colorectal adenoma. ROC analysis showed that the areas under the ROC curves (AUCs) of IFOBT, CA199, and NLR in predicting advanced colorectal adenoma were 0.644 (95%CI: 0.602-0.686), 0.639 (95%CI: 0.598-0.679), and 0.645 (95%CI: 0.605-0.685), respectively. The optimal cutoff values for NLR and CA199 were 2.04 and 7.87 U/mL, respectively. The sensitivity and specificity of IFOBT, CA199, and NLR in predicting advanced colorectal adenoma were 34.6% and 94.2%, 53.9% and 66.1%, and 50.2% and 71.8%, respectively. The AUC of combination of the three biomarkers for the diagnosis of advanced adenoma was 0.752 (95%CI: 0.716-0.788), with a sensitivity of 52.9%and specificity of 82.8%. In the subgroup analysis, there were significant differences between the IFOBT(+) subgroup and IFOBT(-) subgroups with regard to tumor location (P = 0.048), diameter (P = 0.000), and differentiation(P = 0.000). There were also significant differences between the low NLR (< 2.04) subgroup and high NLR (≥ 2.04) subgroup with regard to gender (P = 0.004), tumor diameter (P = 0.028), and tumor differentiation (P = 0.000).

CONCLUSION

Advanced colorectal adenoma is associated with advanced age, smoking, diabetes, and previous cholecystectomy, and more attention should be paid to populations with these risk factors. IFOBT, NLR, and CA199 have appreciated diagnostic value for advanced colorectal adenoma, with the combination of all three having the highest diagnostic value.

Evidence-based clinical practice guidelines for management of colorectal polyps

BACKGROUND

The Japanese Society of Gastroenterology (JSGE) published ''Daicho Polyp Shinryo Guideline 2014'' in Japanese and a part of this guideline was published in English as "Evidence-based clinical practice guidelines for management of colorectal polyps" in the Journal of Gastroenterology in 2015. A revised version of the Japanese-language guideline was published in 2020, and here we introduce a part of the contents of revised version.

METHODS

The guideline committee discussed and drew up a series of clinical questions (CQs). Recommendation statements for the CQs were limited to items with multiple therapeutic options. Items with established conclusions that had 100% agreement with previous guidelines (background questions) and items with no (or old) evidence that are topics for future research (future research questions: FRQs) were given descriptions only. To address the CQs and FRQs, PubMed, ICHUSHI, and other sources were searched for relevant articles published in English from 1983 to October 2018 and articles published in Japanese from 1983 to November 2018. The Japan Medical Library Association was also commissioned to search for relevant materials. Manual searches were performed for questions with insufficient online references.

RESULTS

The professional committee created 18 CQs and statements concerning the current concept and diagnosis/treatment of various colorectal polyps, including their epidemiology, screening, pathophysiology, definition and classification, diagnosis, management, practical treatment, complications, and surveillance after treatment, and other colorectal lesions (submucosal tumors, nonneoplastic polyps, polyposis, hereditary tumors, ulcerative colitis-associated tumors/carcinomas).

CONCLUSIONS

After evaluation by the moderators, evidence-based clinical practice guidelines for management of colorectal polyps were proposed for 2020. This report addresses the therapeutic related CQs introduced when formulating these guidelines.

Heterogeneity in colorectal cancer incidence among people recommended 3-yearly surveillance post-polypectomy: a validation study

BACKGROUND

 Colonoscopy surveillance is recommended for patients at increased risk of colorectal cancer (CRC) following adenoma removal. Low-, intermediate-, and high-risk groups are defined by baseline adenoma characteristics. We previously examined intermediate-risk patients from hospital data and identified a higher-risk subgroup who benefited from surveillance and a lower-risk subgroup who may not require surveillance. This study explored whether these findings apply in individuals undergoing CRC screening.

METHODS

 This retrospective study used data from the UK Flexible Sigmoidoscopy Screening Trial (UKFSST), English CRC screening pilot (ECP), and US Kaiser Permanente CRC prevention program (KPCP). Screening participants (50 - 74 years) classified as intermediate-risk at baseline colonoscopy were included. CRC data were available through 2006 (KPCP) or 2014 (UKFSST, ECP). Lower- and higher-risk subgroups were defined using our previously identified baseline risk factors: higher-risk participants had incomplete colonoscopies, poor bowel preparation, adenomas ≥ 20 mm or with high-grade dysplasia, or proximal polyps. We compared CRC incidence in these subgroups and in the presence vs. absence of surveillance using Cox regression.

RESULTS

 Of 2291 intermediate-risk participants, 45 % were classified as higher risk. Median follow-up was 11.8 years. CRC incidence was higher in the higher-risk than lower-risk subgroup (hazard ratio [HR] 2.08, 95 % confidence interval [CI] 1.07 - 4.06). Surveillance reduced CRC incidence in higher-risk participants (HR 0.35, 95 %CI 0.14 - 0.86) but not statistically significantly so in lower-risk participants (HR 0.41, 95 %CI 0.12 - 1.38).

CONCLUSION

 As previously demonstrated for hospital patients, screening participants classified as intermediate risk comprised two risk subgroups. Surveillance clearly benefited the higher-risk subgroup.

Current Status of Colorectal Cancer and Its Public Health Burden in Thailand

Colorectal cancer (CRC) accounts for approximately 10.3% of new cancer cases in Thailand and is currently the 3rd most prevalent cancer found among the Thai population. Starting in 2017, the Thai government announced the national CRC screening program as a response to this important issue. Among the 70 million people currently residing in Thailand, 14 million require screening, while there are approximately a total of 1,000 endoscopists available to perform colonoscopy. Due to the limited resources and shortage of endoscopists in Thailand, applying a population-based one-step colonoscopy program as a primary screening method is not feasible. To reduce colonoscopy workload, with the help of others, including village health volunteers, institution-based health personnel, reimbursement coders, pathologists, and patients due for CRC screening, a two-step approach of one-time fecal immunochemical test (FIT), which prioritizes and filters out subjects for colonoscopy, is chosen. Moreover, additional adjustments to the optimal FIT cutoff value and the modified Asia-Pacific Colorectal Screening risk score, including body weight, were proposed to stratify the priority of colonoscopy schedule. This article aims to give an overview of the past and current policy developmental strategies and the current status of the Thailand CRC screening program.

Development of a decision aid to support colorectal cancer screening: perspectives of Asians in an endemic urban community-a qualitative research study

BACKGROUND

Colorectal cancer (CRC) is a common malignancy worldwide. Despite being the most common cancer in Singapore, CRC screening rate remains low due to knowledge deficits, social reasons such as inconvenience and a lack of reminder or recommendation. A decision aid (DA) may facilitate an individual's decision-making to undertake CRC screening by addressing misconceptions and barriers. We postulate that a more person-centred and culturally adapted DA will better serve the local population. The views of the target users are thus needed to develop such a DA. A CRC screening DA prototype has been adapted from an American DA to cater to the Asian users. This study aimed to explore user perspectives on an adapted CRC screening DA-prototype in terms of the design, content and perceived utility.

METHODS

The study used in-depth interviews (IDIs) and focus group discussions (FGDs) to gather qualitative data from English-literate multi-ethnic Asian adults aged 50 years old and above. They had yet to screen for CRC before they were recruited from a public primary care clinic in Singapore. The interviews were audio-recorded, transcribed and analysed to identify emergent themes via thematic analysis.

RESULTS

This study included 27 participants involved in 5 IDI and 5 FGDs. Participants found the DA easily comprehensible and of appropriate length. They appreciated information about the options and proposed having multi-lingual DAs. The design, in terms of the layout, size and font, was well-accepted but there were suggestions to digitalize the DA. Participants felt that the visuals were useful but there were concerns about modesty due to the realism of the illustration. They would use the DA for information-sharing with their family and for discussion with their doctor for decision making. They preferred the doctor's recommendation for CRC screening and initiating the use of the DA.

CONCLUSIONS

Participants generally had favourable perceptions of the DA-prototype. A revised DA will be developed based on their feedback. Further input from doctors on the revised DA will be obtained before assessing its effectiveness to increase CRC screening rate in a randomized controlled trial.

Colorectal Cancer: In the Pursuit of Health Equity

Colorectal cancer mortality has decreased considerably following the adoption of national screening programs, yet, within at-risk subgroups, there continue to be measurable differences in clinical outcomes from variations in screening, receipt of chemotherapy, radiation or surgery, access to clinical trials, research participation, and survivorship. These disparities are well-described and some have worsened over time. Disparities identified have included race and ethnicity, age (specifically young adults), socioeconomic status, insurance access, geography, and environmental exposures. In the context of the COVID-19 pandemic, colorectal cancer care has necessarily shifted dramatically, with broad, immediate uptake of telemedicine, transition to oral medications when feasible, and considerations for sequence of treatment. However, it has additionally marginalized patients with colorectal cancer with historically disparate cancer-specific outcomes; among them, uninsured, low-income, immigrant, and ethnic-minority patients-all of whom are more likely to become infected, be hospitalized, and die of either COVID-19 or colorectal cancer. Herein, we outline measurable disparities, review implemented solutions, and define strategies toward ensuring that all have a fair and just opportunity to be as healthy as possible.

Prophylactic clipping not effective in preventing post-polypectomy bleeding for < 20-mm colon polyps: A multicenter, open-label, randomized controlled trial

BACKGROUND AND AIM

Prophylactic clipping (PC) after polypectomy has the potential to prevent post-polypectomy bleeding (PPB). We aimed to evaluate the effectiveness of PC in preventing PPB for < 20-mm polyps.

METHODS

This multicenter, open-label, randomized controlled trial conducted from December 2013 to June 2017 at 10 institutions randomly assigned 1080 patients with < 20-mm colon polyps to the non-PC and PC groups. Allocation factors were institution, antiplatelet drug use, and polyp number. The primary endpoint was differences in PPB rates between the groups. The severity of PPB and post-procedural abdominal symptoms were also investigated. These endpoints in intention-to-treat and per-protocol (PP) analyses were evaluated.

RESULTS

We investigated 1039 patients with 2960 lesions. There was no significant difference between the groups in characteristics including age, sex, hypertension, diabetes, hyperlipidemia, antiplatelet drug use, and lesion characteristics such as type and size. Excluding the clip used in the non-PC group, intraoperative bleeding, and deviation of protocol, 903 patients were investigated in PP analysis. There was no significant difference in the PPB rate between the non-PC and PC groups (2.7% vs 2.3%, P = 0.6973 [intention-to-treat analysis]; 3.0 vs 2.4%, P = 0.7353 [PP analysis]). Severe PPB (≥ grade 3) was similar between the groups. Total procedure time was significantly shorter in the non-PC group than in the PC group (31 vs 36 min, P = 0.0002). Post-procedural abdominal fullness was less common in the non-PC group than in the PC group (20.8% vs 25.6%, P = 0.0833).

CONCLUSION

Prophylactic clipping is not effective in preventing PBB for < 20-mm colon polyps (UMIN000012163).

Colorectal polyp characterization with endocytoscopy: Ready for widespread implementation with artificial intelligence?

Endocytoscopy provides an in-vivo visualization of nuclei and micro-vessels at the cellular level in real-time, facilitating so-called "optical biopsy" or "virtual histology" of colorectal polyps/neoplasms. This functionality is enabled by 520-fold magnification power with endocytoscopy and recent breakthroughs in artificial intelligence (AI) allowing a great advance in endocytoscopic imaging; interpretation of images is now fully supported by AI tool which outputs predictions of polyp histopathology during colonoscopy. The advantage of the use of AI during optical biopsy can be appreciated especially by non-expert endoscopists who to increase performance. This paper provides an overview of the latest evidence on colorectal polyp characterization with endocytoscopy combined with AI and identify the barriers to its widespread implementation.

Long term outcomes of colon polyps with high grade dysplasia following endoscopic resection

BACKGROUND

The risk of recurrent colonic adenoma associated with high-grade dysplasia (HGD) colon polyps at baseline colonoscopy remains unclear. We conducted a clinical cohort study with patients who underwent polypectomy during screen colonoscopy to assess recurrent colonic adenoma risk factors.

METHODS

11,565 patients at our facility underwent screen colonoscopy between September 1998 and August 2007. Data from patients with HGD colon polyps who had undergone follow-up colonoscopy were included for analysis.

RESULTS

Data from 211 patients was included. Rates of metachronous adenoma and advanced adenoma at follow-up were 58% and 20%, respectively. Mean follow-up period was 5.5 ± 1.8 (3-12) years. Univariate logistic regression analysis revealed that an adenoma count of ≥ 3 at baseline colonoscopy was strongly associated with overall recurrence, multiple recurrence, advanced recurrence, proximal recurrence, and distal adenoma recurrence with odds ratios of 4.32 (2.06-9.04 95% CI), 3.47 (1.67-7.22 95% CI), 2.55 (1.11-5.89 95% CI), 2.46 (1.16-5.22 95% CI), 2.89 (1.44-5.78 95% CI), respectively. Multivariate analysis revealed gender (male) [P = 0.010; OR 3.09(1.32-7.25 95% CI)] and adenoma count ≥ 3 [P = 0.002; OR 3.08(1.52-6.24 95% CI)] at index colonoscopy to be significantly associated with recurrence of advanced adenoma.

CONCLUSION

Recurrence of colonic adenoma at time of follow-up colonoscopy is common in patients who undergo polypectomy for HGD colon adenomas during baseline colonoscopy. Risk of further developing advanced adenomas is associated with gender and the number of colon adenomas present.

Randomised comparison of postpolypectomy surveillance intervals following a two-round baseline colonoscopy: the Japan Polyp Study Workgroup

OBJECTIVE

To assess whether follow-up colonoscopy after polypectomy at 3 years only, or at 1 and 3 years would effectively detect advanced neoplasia (AN), including nonpolypoid colorectal neoplasms (NP-CRNs).

DESIGN

A prospective multicentre randomised controlled trial was conducted in 11 Japanese institutions. The enrolled participants underwent a two-round baseline colonoscopy (interval: 1 year) to remove all neoplastic lesions. Subsequently, they were randomly assigned to undergo follow-up colonoscopy at 1 and 3 years (2-examination group) or at 3 years only (1-examination group). The incidence of AN, defined as lesions with low-grade dysplasia ≥10 mm, high-grade dysplasia or invasive cancer, at follow-up colonoscopy was evaluated.

RESULTS

A total of 3926 patients were enrolled in this study. The mean age was 57.3 (range: 40-69) years, and 2440 (62%) were male. Of these, 2166 patients were assigned to two groups (2-examination: 1087, 1-examination: 1079). Overall, we detected 29 AN in 28 patients at follow-up colonoscopy in both groups. On per-protocol analysis (701 in 2-examination vs 763 in 1-examination group), the incidence of AN was similar between the two groups (1.7% vs 2.1%, p=0.599). The results of the non-inferiority test were significant (p=0.017 in per-protocol, p=0.001 in intention-to-treat analysis). NP-CRNs composed of dominantly of the detected AN (62%, 18/29), and most of them were classified into laterally spreading tumour non-granular type (83%, 15/18).

CONCLUSION

After a two-round baseline colonoscopy, follow-up colonoscopy at 3 years detected AN, including NP-CRNs, as effectively as follow-up colonoscopies performed after 1 and 3 years.