Colonoscopy surveillance after polypectomy may be extended beyond five years

Risk of recurrent advanced colorectal neoplasia in individuals with baseline non-advanced neoplasia followed up at 5 vs 7-10 years

BACKGROUND AND AIM

Colorectal cancer (CRC) is one of the commonest cancers, especially among the Asian populations. We compared the recurrence rate of advanced colorectal neoplasia (ACN) at 5 year vs 7-10 years among individuals with non-advanced adenoma (NAA) detected and polypectomized at baseline colonoscopy in a large Chinese population.

METHODS

We extracted data of a large Chinese population with NAA polypectomized who received surveillance colonoscopy after 5 or 7-10 years from a large database (2008-2018). The outcome variable included recurrence of ACN at surveillance colonoscopy. We examined the association between length of surveillance and the outcome variable, whilst controlling for risk factors of colorectal cancer.

RESULTS

We include 109 768 subjects who have received a baseline colonoscopy from our dataset. They were aged 67.35 (SD 9.84) years, and 60.9% of them were male subjects. The crude 5-year and 10-year recurrence rate of ACN was 1.50% and 2.42%, respectively (crude odds ratio = 1.629, 95% CI 1.362 to 1.949, P < 0.001). From the binary logistic regression model, individuals with surveillance colonoscopy performed at 10 years had a statistically higher recurrence rate of ACN than those followed-up at 5 year (adjusted odds ratio [aOR] = 1.544, 95% CI 1.266 to 1.877, P < 0.001), but the effect size of aOR is small.

CONCLUSIONS

There is a small difference in recurrence of ACN between individuals who received colonoscopy workup at 5 years vs 7-10 years. These findings support a 7-10 years surveillance period after baseline NAA was polypectomized.

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.

A computer-aided diagnosis system using white-light endoscopy for the prediction of conventional adenoma with high grade dysplasia

OBJECTIVES

We developed a computer-aided diagnosis system called ECRCCAD using standard white-light endoscopy (WLE) for predicting conventional adenomas with high-grade dysplasia (HGD) to optimise the patients' management decisions during colonoscopy.

METHODS

Pretraining model was used to fine-tune the model parameters by transfer learning. 2,397 images of HGD and 2,487 low-grade dysplasia (LGD) images were randomly assigned (8:1:1) to the training, optimising, and internal validation dataset. The prospective validation dataset is the frames accessed from colonoscope videoes. One independent rural hospital provided an external validation dataset. Histopathological diagnosis was used as the standard criterion. The capability of the ECRCCAD to distinguish HGD was assessed and compared with two expert endoscopists.

RESULTS

The accuracy, sensitivity and specificity for diagnosis of HGD in the internal validation set were 90.5%, 93.2%, 87.9%, respectively. While 88.2%, 85.4%, 89.8%, respectively, for the external validation set. For the prospective validation set, ECRCCAD achieved an AUC of 93.5% in diagnosing HGD. The performance of ECRCCAD in diagnosing HGD was better than that of the expert endoscopist in the external validation set (88.2% vs. 71.5%, P < 0.0001).

CONCLUSION

ECRCCAD had good diagnostic capability for HGD and enabled a more convenient and accurate diagnosis using WLE.

Surveillance Recommendation for Colonoscopy after Polypectomy

The incidence and mortality of colorectal cancer (CRC) have declined over the past several decades, largely due to improvement and uptake in screening, particularly with colonoscopy. The US Multi-Society Task Force on CRC published guidelines for surveillance after polypectomy in 2012, which were updated in 2020 with some important changes, and this review will provide an updated overview of evidence and outcomes of surveillance after polypectomy. Notable modifications to surveillance guidelines include increasing interval time between colonoscopies from 5 to 7 to 10 years for 1 to 2 low-risk adenomas (<10 mm) and from 3 years to 3 to 5 years when 3 to 4 low-risk adenomas are identified.

Establishment and Verification of Scoring System for Colorectal Adenoma Recurrence

Objective

The purpose of this study was to establish and verify a risk-scoring system for colorectal adenoma recurrence.

Methods

A total of 359 patients with colorectal adenoma who underwent polypectomy from October 2017 to December 2018 were included in this retrospective study. Information including taking traditional Chinese medicine, demographic characteristics, adenoma characteristics were collected. The patients will review the colonoscopy one year after surgery. The patients were divided into a modeling cohort (216 cases) and a model validation cohort (143 cases) according to the ratio of 6:4. Modeling and model verification were performed by logistic regression, ROC curve, nomogram (calibration chart) and other methods.

Results

After adjusting for confounding factors by logistic regression, it was found that taking Chinese medicine, the number, size, site, pathological type and morphology of adenoma were independent influencing factors for the recurrence of colorectal adenoma. The area under the ROC curve (AUC) in the model validation cohort of established risk scoring system was 0.771 (95% CI: 0.694–0.847), indicating that there was good consistency.

Conclusion

The established risk prediction model of colorectal adenoma recurrence and its risk scoring system performed well and had high predictive value.

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.

Risk of metachronous neoplasia on surveillance colonoscopy among young and older patients after polypectomy

BACKGROUND AND AIMS

Few reports address the appropriate colonoscopy surveillance interval for individuals <50-years-old. We compared the risk of metachronous neoplasia among young (<50 years), adult (50-74 years) and older (≥75 y) age groups.

METHODS

This was a single center retrospective cohort study. Eligible subjects underwent their first colonoscopy with polypectomy between 2005 and 2014 and had at least one surveillance colonoscopy 3-5 years later. Patients (N = 495) were stratified at baseline into low-risk adenoma (LRA) and advanced adenoma groups. Study outcomes were overall and high-risk neoplasia at surveillance colonoscopy.

RESULTS

In the baseline LRA-group (N = 201), the 5-year risk of metachronous high-risk neoplasia was 12.5%, 15.2% and 22.5% (P = 0.426) in the young, adult and older age groups, respectively. In the baseline advanced adenoma group (N = 294), the 3-year risk of metachronous high-risk neoplasia was 13.3%, 14.8% and 25.3% (P = 0.041), respectively. In multivariate analysis, the only risk factor for metachronous high-risk neoplasia was older age (OR 1.876, CI 1.087-3.238; P = 0.024).

CONCLUSIONS

Considering the comparable risk of metachronous high-risk neoplasia in young and adult patients, surveillance recommendations after polypectomy should not differ. Since this risk is higher among older people, more frequent surveillance schedule can be considered for this age group but should be individualized.

Long-term Risk of Colorectal Cancer and Related Death After Adenoma Removal in a Large, Community-based Population

BACKGROUND & AIMS

The long-term risks of colorectal cancer (CRC) and CRC-related death following adenoma removal are uncertain. Data are needed to inform evidence-based surveillance guidelines, which vary in follow-up recommendations for some polyp types. Using data from a large, community-based integrated health care setting, we examined the risks of CRC and related death by baseline colonoscopy adenoma findings.

METHODS

Participants at 21 medical centers underwent baseline colonoscopies from 2004 through 2010; findings were categorized as no-adenoma, low-risk adenoma, or high-risk adenoma. Participants were followed until the earliest of CRC diagnosis, death, health plan disenrollment, or December 31, 2017. Risks of CRC and related deaths among the high- and low-risk adenoma groups were compared with the no-adenoma group using Cox regression adjusting for confounders.

RESULTS

Among 186,046 patients, 64,422 met eligibility criteria (54.3% female; mean age, 61.6 ± 7.1 years; median follow-up time, 8.1 years from the baseline colonoscopy). Compared with the no-adenoma group (45,881 patients), the high-risk adenoma group (7563 patients) had a higher risk of CRC (hazard ratio [HR] 2.61; 95% confidence interval [CI] 1.87-3.63) and related death (HR 3.94; 95% CI 1.90-6.56), whereas the low-risk adenoma group (10,978 patients) did not have a significant increase in risk of CRC (HR 1.29; 95% CI 0.89-1.88) or related death (HR 0.65; 95% CI 0.19-2.18).

CONCLUSIONS

With up to 14 years of follow-up, high-risk adenomas were associated with an increased risk of CRC and related death, supporting early colonoscopy surveillance. Low-risk adenomas were not associated with a significantly increased risk of CRC or related deaths. These results can inform current surveillance guidelines for high- and low-risk adenomas.

Baseline Colonoscopy Findings Associated With 10-Year Outcomes in a Screening Cohort Undergoing Colonoscopy Surveillance

BACKGROUND & AIMS

Few studies have evaluated long-term outcomes of ongoing colonoscopic screening and surveillance in a screening population. We aimed to determine the 10-year risk for advanced neoplasia (defined as adenomas ≥10mm, adenomas with villous histology or high-grade dysplasia, or colorectal cancer [CRC]) and assessed whether baseline colonoscopy findings were associated with long-term outcomes.

METHODS

We collected data from the Department of Veterans Affairs Cooperative Studies Program Study on 3121 asymptomatic veterans (50-75 years old) who underwent a screening colonoscopy from 1994 through 1997 at 13 medical centers and were then followed for 10 years or until death. We included 1915 subjects with at least 1 surveillance colonoscopy and estimated cumulative incidence of advanced neoplasia by Kaplan-Meier curves. We then fit a longitudinal joint model to estimate risk of advanced neoplasia at each subsequent examination after baseline, adjusting for multiple colonoscopies within individuals.

RESULTS

Through 10 years of follow-up, there were 146 individuals among all baseline colonoscopy groups found to have at least 1 incident advanced neoplasia. The cumulative 10-year incidence of advanced neoplasia was highest among those with baseline CRC (43.7%; 95% CI 13.0%-74.4%), followed by those with baseline advanced adenoma (AA) (21.9%; 95% CI 15.7-28.1). The cumulative 10-year incidence of advanced neoplasia was 6.3% (95% CI 4.1%-8.5%) and 4.1% (95% CI 2.7%-5.4%) for baseline 1 to 2 small adenomas (<1cm, and without villous histology or high-grade dysplasia) and no neoplasia, respectively (log-rank P = .10). After adjusting for prior surveillance, the risk of advanced neoplasia at each subsequent examination was not significantly increased in veterans with 1 or 2 small adenomas at baseline (odds ratio 0.96; 95% CI 0.67-1.41) compared with veterans with no baseline neoplasia.

CONCLUSIONS

Baseline screening colonoscopy findings associate with advanced neoplasia within 10 years. Individuals with only 1 or 2 small adenomas at baseline have a low risk of advanced neoplasia over 10 years. Alternative surveillance strategies, could be considered for these individuals.

Outcomes at follow-up of negative colonoscopy in average risk population: systematic review and meta-analysis

OBJECTIVE

To review and summarise the evidence on the prevalence of colorectal adenomas and cancers at a follow-up screening colonoscopy after negative index colonoscopy, stratified by interval between examinations and by sex.

DESIGN

Systematic review and meta-analysis of all available studies.

DATA SOURCES

PubMed, Web of Science, and Embase. Two investigators independently extracted characteristics and results of identified studies and performed standardised quality ratings.

ELIGIBILITY CRITERIA

Studies assessing the outcome of a follow-up colonoscopy among participants at average risk for colorectal cancer with a negative previous colonoscopy (no adenomas).

RESULTS

28 studies were identified, including 22 cohort studies, five cross sectional studies, and one case-control study. Findings for an interval between colonoscopies of one to five, five to 10, and more than 10 years were reported by 17, 16, and three studies, respectively. Summary estimates of prevalences of any neoplasm were 20.7% (95% confidence interval 15.8% to 25.5%), 23.0% (18.0% to 28.0%), and 21.9% (14.9% to 29.0%) for one to five, five to 10, and more than 10 years between colonoscopies. Corresponding summary estimates of prevalences of any advanced neoplasm were 2.8% (2.0% to 3.7%), 3.2% (2.2% to 4.1%), and 7.0% (5.3% to 8.7%). Seven studies also reported findings stratified by sex. Summary estimates stratified by interval and sex were consistently higher for men than for women.

CONCLUSIONS

Although detection of any neoplasms was observed in more than 20% of participants within five years of a negative screening colonoscopy, detection of advanced neoplasms within 10 years was rare. Our findings suggest that 10 year intervals for colonoscopy screening after a negative colonoscopy, as currently recommended, may be adequate, but more studies are needed to strengthen the empirical basis for pertinent recommendations and to investigate even longer intervals.

STUDY REGISTRATION

Prospero CRD42019127842.

Yield and Practice Patterns of Surveillance Colonoscopy Among Older Adults: An Analysis of the GI Quality Improvement Consortium

OBJECTIVES

There is little guidance regarding when to stop surveillance colonoscopy in individuals with a history of adenomas or colorectal cancer (CRC). We evaluated both yield and recommendations for follow-up colonoscopy in a large cohort of older individuals undergoing colonoscopy, using the GI Quality Improvement Consortium registry.

METHODS

We analyzed the yield of colonoscopy in adults aged ≥75 years, comparing those who had an indication of surveillance as opposed to an indication of diagnostic or screening, stratified by 5-year age groups. Our primary outcome was CRC and advanced lesions. We also evaluated recommended follow-up intervals by age and findings.

RESULTS

Between 2010 and 2017, 376,686 colonoscopies were performed by 3,976 endoscopists at 628 sites, of which 43.2% were for surveillance. Detection of CRC among surveillance patients increased with age from 0.51% (age 75-79 years) to 1.8% (age ≥ 90 years); however, these risks were lower when compared with both the diagnostic and screening for the same age band (P < 0.0001). Yield of advanced lesions also increased by every 5-year interval of age across all groups by indication. Even at the most advanced ages and in those with nonadvanced findings, only a minority of patients were recommended for no further colonoscopy. For example, in patients aged 90 years and older with only low risk findings, 62.9% were recommended to repeat colonoscopy.

DISCUSSION

Surveillance colonoscopy is frequently recommended at advanced ages even when recent findings may be clinically insignificant. Further work is needed to develop guidelines to inform best practice around when to stop surveillance in older adults.

Further Defining the 2012 Multi-Society Task Force Guidelines for Surveillance of High-risk Adenomas: Is a 3-Year Interval Needed for All Patients?

GOALS

We set out to determine whether variation from this 3-year follow-up interval was associated with the finding of subsequent high-risk adenoma (HRA).

BACKGROUND

HRAs include the following: (1) an adenoma measuring ≥10 mm, (2) ≥3 adenomas found during a single procedure, and (3) an adenoma with high-grade dysplasia or villous architecture. The current Multi-Society Task Force guideline for timing of surveillance colonoscopy after removal of a HRA is 3 years.

STUDY

In 2016, we analyzed 495 patients who had a HRA removed during a 2008 colonoscopy. We compared the frequency of finding another HRA at follow-up intervals. We used the current guidelines as our referent group and performed logistical regression to identify whether any patient characteristics, procedural factors, or type of HRA predicted the development of HRAs on follow-up colonoscopy.

RESULTS

Individuals who followed-up at a median of 4.5 years did not have more HRA on follow-up compared with those who followed-up at 3 years (25.2% vs. 21.0%, P=0.062). These groups had similar baseline characteristics. Older individuals, male gender, having a history of polyps, and piecemeal resection of an HRA predicted future HRAs. The removal of ≥3 adenomas in 2008 as well as a combination of multiple, large, and advanced polyps showed a higher risk of future HRAs.

CONCLUSIONS

The 2012 Multi-Society Task Force recommendation of 3-year follow-up after removal of HRAs may not apply to all patients. We showed that a combination of patient demographics, procedural factors, and pathology best determines the surveillance colonoscopy interval.

The significance of the small adenoma: a longitudinal study of surveillance colonoscopy in an Australian population

BACKGROUND

The international guidelines for surveillance following the finding of a small tubular adenoma vary between no surveillance or colonoscopy at 5 or 10 years, whereas surveillance after an advanced adenoma is 3 years. Optimization of surveillance reduces the risk of colorectal cancer (CRC) with efficient use of colonoscopy resources. We assessed the risks of advanced colorectal neoplasia following a baseline finding of a small adenoma compared with advanced adenoma.

PATIENTS AND METHODS

A retrospective audit was undertaken of patients enrolled in a CRC surveillance program, wherein regular colonoscopies and screening with faecal immunochemical test (FIT) were provided. Patients diagnosed with either small or advanced adenoma followed by at least one surveillance colonoscopy were included. Advanced adenoma included adenomas with features of villous change, size of at least 10 mm, high-grade dysplasia, three or more small tubular adenomas and traditional and sessile serrated adenomas. Subdistribution hazard ratios were calculated for advanced neoplasia (CRC or advanced adenoma).

RESULTS

Overall, 378 patients (62.6±11.2 years, 57.9% male) were included, with 44.2% diagnosed with small adenoma and 55.5% with advanced adenoma at baseline. The crude cumulative incidence of advanced neoplasia at first surveillance was 13.2 and 18.5% after small and advanced adenoma (P=0.16) (at 45.9 and 35.6 months, respectively), which became significant for advanced adenoma after adjustment (subdistribution hazard ratio=2.55, 95% confidence interval=1.49-4.35, P<001). A positive FIT was the only independent predictor of advanced neoplasia after a small adenoma at baseline colonoscopy (odds ratio=5.05, 95% confidence interval=1.27-20.02, P=0.02).

CONCLUSIONS

The risk of advanced neoplasia following a small adenoma was lower than that following an advanced adenoma, but was strongly predicted by a positive FIT. Reducing frequency of colonoscopy while providing regular FIT might be a more efficient use of resources for this population.

Risk of metachronous advanced lesions after resection of diminutive and small, non-advanced adenomas

BACKGROUND AND AIMS

Current post-polypectomy surveillance interval guidelines do not discriminate between 1-2 diminutive (1-5mm) and small (6-9mm) non-advanced adenomas. This study compared the risk for metachronous advanced lesions in these groups.

METHODS

Patients with 1-2 diminutive, non-advanced adenomas and no further advanced lesions, and patients with no polyps at baseline colonoscopy were retrospectively analyzed to determine the rate of metachronous advanced lesions. These were defined as the combined rate of colon cancer, advanced adenoma and ≥ 3 non-advanced adenomas at surveillance colonoscopy. Polyp size was measured either subjectively by the endoscopist or by pathology-based measurements.

RESULTS

Among patients with diminutive (n = 395) and small polyps (n = 110), advanced lesions were found in 68 patients (17.2%) and 16 patients (14.5%), respectively (P = 0.53), during a mean follow-up of 4.3 ± 0.9 years. In contrast, advanced lesions were observed in 33 patients (6.6%) in the no polyp group (n = 505), significantly lower than diminutive (P = 0.000) and small polyp groups (P = 0.002), despite a mean follow-up duration of 6.1 ± 1.9 years. The rate of metachronous advanced lesions was also similar between patients with 1-3mm polyps (16%) versus 7-9mm polyps (15.8%).

CONCLUSIONS

Our findings suggest that among patients who underwent polypectomy of up to 2 non-advanced adenomas, those with diminutive and small polyps have the same risk of metachronous advanced lesions; thus, supporting uniform recommendations for surveillance colonoscopy for these lesions.

Cost-effectiveness analysis of postpolypectomy colonoscopy surveillance using Japanese data

OBJECTIVE

Recommendations vary on postpolypectomy surveillance, and no consensus has been reached even regarding the necessity of risk stratification based on polyp characteristics for surveillance. We examined an optimal postpolypectomy surveillance program by performing a cost-effectiveness analysis.

METHODS

We performed a Markov model analysis using parameters based on Japanese data and evaluated four postpolypectomy surveillance programs with respect to their effectiveness in terms of quality-adjusted life-years (QALYs), cost-effectiveness and required number of colonoscopies. Two were non-risk-stratified programs with 1-year (program 1) and 3-year (program 2) postpolypectomy surveillance colonoscopy, and the other two were risk-stratified programs. In program 3, surveillance colonoscopy was performed 3, 10 and 10 years after resection of advanced adenomas, low-risk adenomatous polyps, and no polyps, respectively. In program 4, those intervals were shortened to 1, 3 and 5 years, respectively.

RESULTS

Risk-stratified programs (3 and 4) yielded higher QALYs with lower costs than non-risk-stratified programs (1 and 2). Program 4 yielded higher QALYs (23.046) and lower required cost (107,717 JPY) than program 3. The required number of colonoscopies for program 4 was 1.2, 1.5 and 1.6 times that for programs 1, 2 and 3, respectively. A probabilistic sensitivity analysis showed that the probability of program 4 being chosen as the most cost-effective was highest.

CONCLUSIONS

After polypectomy, risk-stratified colonoscopy surveillance based on the polyp characteristics should be considered. A risk-stratified program with relatively short examination intervals could be effective and cost-effective in Japan, although further investigation and consideration of colonoscopy capacity are required.

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

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

Neoplasia at 10-year follow-up screening colonoscopy in a private U.S. practice: comparison of yield to first-time examinations

BACKGROUND AND AIMS

Prior studies assessing the yield of a second screening colonoscopy performed 10 years after an initial screening colonoscopy with negative results did not include a control group of persons undergoing a first screening colonoscopy during the same time interval. Our aim was to describe the incidence of neoplasia at a second screening colonoscopy (performed at least 8 years after the first colonoscopy) in average-risk individuals and compare it with the yield of first screening examinations performed during the same time interval.

METHODS

Review of a database of outpatient screening colonoscopies performed between January 2010 and December 2015 in an Atlanta private practice.

RESULTS

A total of 2105 average-risk individuals underwent screening colonoscopy, including 470 individuals (53.6% female; mean age ± standard deviation [SD] 64.0 ± 3.9 years) who underwent a second screening examination. In those undergoing second screening, the mean (± SD) interval between examinations was 10.4 years (± 1.1 years, range 8-15 years). At second screening, the polyp detection rate, adenoma detection rate, and advanced neoplasm rate were 44.7%, 26.6%, and 7.4%, respectively. Of 40 advanced neoplasms in 35 individuals, 33 (82.5%) were proximal to the sigmoid colon, and there were no cancers. During the same interval, 1635 individuals (49.4% female; mean age [± SD] 52.6 ± 3.4 years) underwent a first screening colonoscopy. The polyp detection rate, adenoma detection rate, and advanced neoplasm detection rate were 53.5%, 32.2%, and 11.7%, respectively. Of 243 advanced neoplasms in 192 individuals, 152 (62.6%) were proximal to the sigmoid colon, and there were no cancers. After adjustment for age, sex, body mass index, and endoscopist, polyp detection rate, adenoma detection rate, and advanced neoplasm detection rate were all lower at the second screening colonoscopies than at first-time colonoscopies (all P < .001).

CONCLUSIONS

Despite being 10 years older, persons with a screening colonoscopy with negative results 10 years earlier had lower rates of adenoma and advanced neoplasm at the second screening examination compared with patients in the same practice undergoing a first screening colonoscopy, and they had no cancers. The fraction of advanced neoplasms that were proximal to the sigmoid colon was high in both first and second screenings. These results support the safety of the recommended 10-year interval between colonoscopies in average-risk persons with an initial examination with negative results.

Adenoma and Polyp Detection Rates in Colonoscopy according to Indication

Background

Adenoma detection rate (ADR) is a validated quality measure for screening colonoscopy, but there are little data for other indications. The distribution of adenomas is not well described for these indications.

Aim

To describe ADR and the adenoma distribution in the proximal and distal colon based on colonoscopy indication.

Methods

Outpatient colonoscopies are subdivided by indication. PDR and ADR for the entire colon and for proximal and distal colon. Data were compared using generalized estimating equations to adjust for clustering amongst endoscopists while controlling for patient age and gender.

Results

3436 colonoscopies were reviewed (51.2%: men (n = 1759)). Indications are screening 49.2%, surveillance 29.3%, change in bowel habit 8.4%, bleeding 5.8%, colitides 3.0%, pain 2.8%, and miscellaneous 1.5%. Overall ADR was 37% proximal ADR 28%, and distal ADR 17%. PDR and ADR were significantly higher in surveillance than in screening (PDR: 69% versus 51%; ADR: 50% versus 33%; p = 0.0001). Adenomas were more often detected in the proximal than in the distal colon, for all indications.

Conclusions

Prevalence of polyps and adenomas differs based on colonoscopy indication. Adenoma detection is highest in surveillance and more commonly detected in the proximal colon. For quality assurance, distinct ADR and PDR targets may need to be established for different colonoscopy indications.

Risk of Advanced Adenoma, Colorectal Cancer, and Colorectal Cancer Mortality in People With Low-Risk Adenomas at Baseline Colonoscopy: A Systematic Review and Meta-Analysis

OBJECTIVES

We conducted a systematic review and meta-analysis of the risk of advanced adenomas (AAs), colorectal cancer (CRC), and/or CRC-related death among individuals with low-risk adenomas (LRAs).

METHODS

We searched PubMed and Embase for studies published between January 2006 and July 2015. Quality and strength of the evidence were rated using the Newcastle-Ottawa Scale (NOS) and the GRADE framework, respectively.

RESULTS

Eleven observational studies (n=64,317) were included. A meta-analysis of eight cohort studies (n=10,139, 3 to 10 years' follow-up) showed a small but statistically significant increase in the incidence of AAs in individuals with LRAs compared with those with a normal baseline colonoscopy (RR 1.55 (95% CI 1.24-1.94); P=0.0001; I²=0%). The pooled 5-year cumulative incidence of AA was 3.28% (95% CI: 1.85-5.10%), 4.9% (95% CI: 3.18-6.97%), and 17.13% (95% CI: 11.97-23.0%) for the no adenoma, LRA, and AA baseline groups, respectively. Two studies, which could not be pooled, showed a reduction in the risk of CRC in individuals with LRAs compared with the general population (standardized incidence ratio 0.68 (95% CI 0.44-0.99) at a median follow-up of 7.7 years and OR 0.4 (95% CI 0.2-0.6) at 3-5 years). One large retrospective cohort study found a 25% reduction in CRC mortality in individuals with LRAs compared with the general population (SMR 0.75 (95% CI 0.63-0.88) at a median follow-up of 7.7 years).

CONCLUSIONS

We observed a small but significant increase in the risk of AAs in people with LRAs compared with those with a normal baseline colonoscopy, but compared with the general population, people with LRAs have significantly lower risks of CRC and of CRC-related mortality.

Risk of advanced lesions at the first follow-up colonoscopy after polypectomy of diminutive versus small adenomatous polyps of low-grade dysplasia

BACKGROUND AND AIMS

The current guidelines for surveillance after polypectomy do not distinguish between diminutive (1-5 mm) and small (6-9 mm) polyps with low-grade dysplasia (LGD). We aimed to evaluate the risk for advanced neoplasia on follow-up colonoscopy.

METHODS

We retrospectively analyzed 443 patients whose worst finding at index colonoscopy was polypectomy of 1 to 5 or 6 to 9 mm polyps with LGD and those who underwent a follow-up colonoscopy.

RESULTS

During a mean follow-up of 32.0 months (interquartile range 13-48 months), advanced neoplasia was found in 26 patients (5.9%). Among all included patients (n = 443), advanced neoplasia was found in 13 of 310 patients (4.2%) of the 1- to 5-mm group versus 13 of 133 patients (9.8%) of the 6- to 9-mm group (hazard ratio [HR], 3.49; 95% confidence interval [CI], 1.6-7.6). Among the patients with 1 to 2 polyps resected (n = 313), advanced neoplasia was found in 8 of 231 patients (3.5%) of the 1- to 5-mm group versus 8 of 82 patients (9.8%) of the 6- to 9-mm group (HR 3.97; 95% CI, 1.47-10.7). Among the patients with ≥3 polyps resected (n = 130), advanced neoplasia was found in 5 of 79 patients (6.3%) of the 1- to 5-mm group versus 5 of 51 patients (9.8%) of the 6- to 9-mm group (HR 2.4; 95% CI, 0.7-8.36). Fair bowel preparation also was associated with the risk for advanced neoplasia at follow-up (HR 3.87, 95% CI, 1.70-8.82).

CONCLUSIONS

Our findings suggest that among patients with up to 9-mm adenomatous polyps, a polyp size of 6 to 9 mm, >2 polyps, and fair bowel preparation are associated with advanced neoplasia.

Surveillance after positive colonoscopy based on adenoma characteristics

BACKGROUND

Patients with adenomatous polyps are at increased risk for developing colorectal cancer based on the characteristics and number of polyps, but less is known about the individual and combined contribution of these factors. This study aimed to better characterize the risk of advanced adenoma and cancer in patients with positive baseline colonoscopy.

METHODS

Patients who had polyps at baseline colonoscopy were included in this retrospective cohort study (N=1165) and were categorized into 6 groups: (1) 1-2 non-advanced adenomas (NAA's), (2) ≥3 NAA's, (3) advanced tubular adenoma, (4) small tubulovillous adenoma (TVA), (5) large TVA and (6) multiple advanced adenomas (MAA's). Findings at surveillance colonoscopy were documented in each group.

RESULTS

The combined incidence of advanced adenoma,  ≥3 NAA's, and colorectal cancer at surveillance colonoscopy was significantly higher in the baseline large TVA (29.2%) than small TVA groups (13.5%, P<0.001), as well as in the MAA's group (44.1%) compared with large TVA group (P=0.02). The incidence of colorectal cancer, however, was not significantly different between the groups.

CONCLUSIONS

The size of the polyp and the number of advanced lesions are more important than its histology for predicting the risk of high-risk metachronous lesions at follow-up.

A comparison of endoscopy versus pathology sizing of colorectal adenomas and potential implications for surveillance colonoscopy

BACKGROUND AND AIMS

The aim of this study was to compare endoscopy and pathology sizing in a large population-based series of colorectal adenomas and to evaluate the implications for patient stratification into surveillance colonoscopy.

METHODS

Endoscopy and pathology sizes available from intact adenomas removed at colonoscopies performed as part of the Northern Ireland Bowel Cancer Screening Programme, from 2010 to 2015, were included in this study. Chi-squared tests were applied to compare size categories in relation to clinicopathologic parameters and colonoscopy surveillance strata according to current American Gastroenterology Association and British Society of Gastroenterology guidelines.

RESULTS

A total of 2521 adenomas from 1467 individuals were included. There was a trend toward larger endoscopy than pathology sizing in 4 of the 5 study centers, but overall sizing concordance was good. Significantly greater clustering with sizing to the nearest 5 mm was evident in endoscopy versus pathology sizing (30% vs 19%, P < .001), which may result in lower accuracy. Applying a 10-mm cut-off relevant to guidelines on risk stratification, 7.3% of all adenomas and 28.3% of those 8 to 12 mm in size had discordant endoscopy and pathology size categorization. Depending on which guidelines are applied, 4.8% to 9.1% of individuals had differing risk stratification for surveillance recommendations, with the use of pathology sizing resulting in marginally fewer recommended surveillance colonoscopies.

CONCLUSIONS

Choice of pathology or endoscopy approaches to determine adenoma size will potentially influence surveillance colonoscopy follow-up in 4.8% to 9.1% of individuals. Pathology sizing appears more accurate than endoscopy sizing, and preferential use of pathology size would result in a small, but clinically important, decreased burden on surveillance colonoscopy demand. Careful endoscopy sizing is required for adenomas removed piecemeal.

Long-term risk of colorectal cancer by gender after positive colonoscopy: population-based cohort study

BACKGROUND

Evidence for surveillance intervals of colonoscopy are primarily based on adenoma recurrence rate rather than on colorectal cancer (C.R.C.) incidence. Little is known about long-term risk of C.R.C. after positive colonoscopy. In view of men have significantly higher C.R.C. risk than women, we aimed to estimate the gender-specific C.R.C. incidence after positive colonoscopy (adenoma or malignant lesion) at follow-up colonoscopy.

METHODS

A retrospective cohort study was conducted using data from a database of colonoscopy screening and surveillance. Patients having had a colonoscopy (January 2010-March 2014) were selected as study subjects and the history of prior colonoscopies was reviewed. Multivariable Weibull regression models were used to estimate the incidence of C.R.C. at follow-up colonoscopy for subjects who were assigned a stratified risk level. The benchmark risk was defined according to a national survey.

RESULTS

The interval incidence of C.R.C. at a 10 year follow-up was 164 (95% C.I. 63-343) and 79 (95% C.I. 26-188) per 100,000 person-years for low-risk men and women respectively, which tallied with our benchmark risk. Men exceeded the benchmark risk in 3-5 years if they had an incomplete polyp removal, ≥3 adenomas during their last colonoscopy or a personal C.R.C. history, and in 7-8 years if they only had familial C.R.C.

HISTORY

Women had a lower risk of C.R.C., and reached a same risk level 3-5 years later than men. Coexisting above risk factors resulted in a sharp increase in the incidence of C.R.C. at follow-up exceeding the benchmark much earlier.

CONCLUSION

Surveillance intervals for men based on incidence of C.R.C. are in line with that recommended by the current guidelines for colonoscopy. However, an extension of 3-5 years may be appropriate for women. To target personalized medicine, a risk predictive model could be used to identify an appropriate surveillance interval for each individual in the future.

Low rate of advanced adenoma formation during a 5-year colonoscopy surveillance period after adequate polypectomy of non-advanced adenoma

AIM

Patients with non-advanced adenoma (NAA) underwent surveillance colonoscopy at intervals shorter than the interval recommended by the guidelines. We aimed to assess the incidence of recurrent advanced adenoma (AA) over a 5-year period and to identify risk factors for recurrence.

METHOD

Patients with and without NAA identified at baseline colonoscopy who had had at least two colonoscopy examinations during the subsequent 5 years were included in the study. Data on the patients' demographics and colorectal findings were extracted from a specially designed colonoscopy database. The primary outcome was the finding of recurrent AA formation. Multivariate analysis was used to identify factors that predict subsequent AA formation at surveillance colonoscopy.

RESULTS

Among 43 155 colonoscopy procedures, 828 cases were identified with NAA (374) and without an adenoma (454). Forty-eight (51.1%) of 94 received a follow-up colonoscopy within 1 year due to an inadequate baseline colonoscopy. Patients with NAA at baseline had a low incidence of AA at an interval of 1-5 years which was not statistically different from patients without adenoma formation at the initial baseline colonoscopy (1.5% vs 2.2%, P = 0.51). The incidence of AA at follow-up colonoscopy performed at 1-3 years and 3-5 years in patients with a baseline NAA was 1.7% and 1.4% (P = 0.59). Age over 50 years and male gender were independent risk factors for AA recurrence within 5 years.

CONCLUSION

Surveillance colonoscopy within 5 years is of little benefit to patients who had an adequate polypectomy of an NAA at baseline. Too frequent reexamination due to concerns about AA recurrence should be avoided.

Risk Factors for Recurrent High-Risk Polyps after the Removal of High-Risk Polyps at Initial Colonoscopy

PURPOSE

Colonoscopic polypectomy and surveillance are important to prevent colorectal cancer and identify additional relative risk factors for adequate surveillance. In this study, we evaluated risk factors related to recurrent high-risk polyps during the surveillance of patients with high-risk polyps.

MATERIALS AND METHODS

We included 434 patients who had high-risk polyps (adenoma≥10 mm, ≥3 adenomas, villous histology, or high-grade dysplasia) on the baseline colonoscopy and underwent at least one surveillance colonoscopy from 2005 to 2011 at Severance Hospital. Data regarding patient characteristics, bowel preparation and polyp size, location, number, and pathological diagnosis were retrospectively collected from medical records. Patients with recurrent high-risk polyps were compared with patients with low-risk or no polyps during surveillance.

RESULTS

Patients were predominantly male (77.4%), with a mean age of 61.0±8.6 years and mean follow-up of 1.5±0.8 years. High-risk polyps recurred during surveillance colonoscopy in 51 (11.8%) patients. Results of multivariate analysis showed that male gender, poor bowel preparation, and a larger number of adenomas were independent risk factors for recurrent high-risk polyps (p=0.047, 0.01, and <0.001, respectively). Compared with high-risk polyps found during initial colonoscopy, high-risk polyps on surveillance colonoscopy had higher proportions of small adenomas, low-risk pathology, and fewer adenomas overall, but there was no difference in location.

CONCLUSION

Male patients and those with poor bowel preparation for colonoscopy or higher numbers of adenomas were more likely to experience recurrent high-risk polyps.

Novel risk stratification for recurrence after endoscopic resection of advanced colorectal adenoma

BACKGROUND

Advanced colorectal adenoma (ACA) refers to adenomas with the following predictive characteristics: ≥1 cm in diameter, and/or villous component, and/or high-grade dysplasia. ACA has high risk of transforming to colorectal cancer, and the recurrence rate is relatively high.

OBJECTIVE

To assess the outcomes of patients with ACA undergoing endoscopic resection and to identify risk factors for local recurrence and development of metachronous advanced neoplasm.

DESIGN

Retrospective cohort study.

SETTING

Tertiary care medical center.

PATIENTS

From 2005 to 2011, the records of 3625 patients who underwent colonoscopic polypectomy at Seoul National University Hospital were retrospectively reviewed. Patients with synchronous colorectal cancers, inflammatory bowel disease, previous colorectal resection, loss to follow-up, and incomplete resection were excluded.

INTERVENTION

Endoscopic resection for ACA.

MAIN OUTCOME MEASUREMENTS

Local recurrence and metachronous advanced neoplasm.

RESULTS

The study included 917 patients with 1206 ACAs. The median duration of follow-up was 28.5 months (interquartile range, 12.8-51.7). Independent risk factors for local recurrence included ACA with 2 or more predictive characteristics (adjusted hazard ratio [HR], 2.46; 95% confidence interval [CI], 1.11-5.48; P = .027) and piecemeal resection (adjusted HR, 6.96; 95% CI, 1.58-30.71; P = .010). Independent risk factors for metachronous advanced neoplasm were male gender (adjusted HR, 1.65; 95% CI, 1.02-2.65; P = .041), ≥3 adenomas (adjusted HR, 2.56; 95% CI, 1.72-3.82; P < .001), and ≥3 ACAs (adjusted HR, 1.44; 95% CI, 1.01-2.06; P = .045).

LIMITATIONS

Retrospective design.

CONCLUSION

ACAs with 2 or more predictive characteristics recurred locally at a higher rate than ACAs with 1 predictive characteristic. These results suggest that patients who are found to have ACAs with 2 or more predictive factors at index colonoscopy are at higher risk for local recurrence, and follow-up colonoscopy should be performed sooner.

Low rate of large polyps (>9 mm) within 10 years after an adequate baseline colonoscopy with no polyps

BACKGROUND & AIMS

Guidelines recommend a 10-year interval between screening colonoscopies with negative results for average-risk individuals. However, many patients are examined at shorter intervals. We investigated outcomes of individuals with no polyps who had repeat colonoscopy in <10 years.

METHODS

Data were collected using the National Endoscopic Database, from 69 gastroenterology centers, on 264,184 asymptomatic subjects who underwent screening colonoscopies from 2000 through 2006, were found to have no polyps, and received another colonoscopy examination within <10 years.

RESULTS

No polyps were found in 147,375 patients during a baseline colonoscopy; 17,525 patients (11.9%) had a follow-up colonoscopy within <10 years, including 1806 (10.3%) who received the follow-up colonoscopy within <1 year. The most common reason for repeating the examination within 1 year was that the first was compromised by inadequate bowel preparation or incomplete examination. Of these patients, 6.5% (95% confidence interval: 5.3-7.6) had large polyp(s) >9 mm-a proportion similar to the prevalence in the average-risk screening population. Reasons that examinations were repeated within 1-5 years included average-risk screening (15.7%), family history of colon polyps or cancer (30.1%), bleeding (31.2%), gastrointestinal symptoms (11.8%), or a positive result from a fecal blood test (5.5%). If the baseline examination was adequate, the incidence of large polyps within 1-5 years after baseline colonoscopy was 3.1% (95% confidence interval: 2.7-3.5) and within years 5-10 years was 3.7% (95% confidence interval: 3.3-4.1).

CONCLUSIONS

Repeat colonoscopies within 10 years are of little benefit to patients who had adequate examinations and were found to have no polyps. Repeat colonoscopies are beneficial to patients when the baseline examination was compromised.

Systematic review with meta-analysis: the incidence of advanced neoplasia after polypectomy in patients with and without low-risk adenomas

BACKGROUND

Patients with one to two tubular adenomas <1 cm in size without high-grade dysplasia (low-risk group) are considered at low risk for colorectal cancer. However, it is uncertain whether they have the same risk of subsequent advanced neoplasia as those with no neoplasia at baseline colonoscopy.

AIM

To compare incidence of metachronous advanced neoplasia between patients in the low-risk adenoma group and those without neoplasia at index colonoscopy.

METHODS

Relevant publications were identified by MEDLINE/EMBASE and other databases for the period 1992-2013. Studies comparing the incidence of post-polypectomy advanced neoplasia (adenomas ≥10 mm/high-grade dysplasia/villous or cancer) between the low-risk group and patients without colorectal neoplasia at the first colonoscopy were included. Detection rates for advanced neoplasia at endoscopic surveillance were extracted. Study quality was ascertained according to Newcastle-Ottawa Scale. Forest plot was produced based on random-effect models. Inter-study heterogeneity was assessed using the I(2) statistic.

RESULTS

Seven studies provided data on 11 387 patients. Mean surveillance periods ranged between 2 and 5 years. Altogether, 267 patients with post-polypectomy advanced neoplasia were detected in the two groups. The incidence of advanced neoplasia was 1.6% (119/7308) in those without neoplasia and 3.6% (148/4079) in those with low-risk adenoma, respectively, corresponding to a relative risk of 1.8 (95% CI: 1.3-2.6). Inter-study heterogeneity was only moderate (I(2) : 37%). No publication bias was present.

CONCLUSIONS

Patients with low-risk adenomas at baseline had a higher risk of metachronous advanced neoplasia than the group with no adenomas at baseline, though the absolute risk was low in both groups.

Risk of colorectal cancer after detection and removal of adenomas at colonoscopy: population-based case-control study

PURPOSE

Empirical evidence for recommendations of surveillance intervals after detection and removal of adenomas at colonoscopy is still sparse and mostly based on observations of adenoma recurrence. We aimed to assess risk of colorectal cancer (CRC) according to time since polypectomy and factors that might be relevant for risk stratification.

METHODS

In a population-based case-control study conducted in Germany, detailed history and results of previous large-bowel endoscopies were obtained by interview and from medical records. Risk of CRC among participants with detection of at least one adenoma at a preceding colonoscopy compared with participants without previous large-bowel endoscopy was assessed according to time since polypectomy among 2,582 cases with CRC and 1,798 matched controls.

RESULTS

Adjusted odds ratios (95% CIs) of CRC for participants with polypectomy less than 3, 3 to 5, and 6 to 10 years ago (using participants without previous endoscopy as reference group) were 0.2 (0.2 to 0.3), 0.4 (0.3 to 0.6), and 0.9 (0.5 to 1.5), respectively. Strong, significant risk reduction within 5 years was consistently seen for women and men, younger and older participants, patients with and without high-risk polyps (three or more polyps, at least one polyp ≥ 1 cm, at least one polyp with villous components), and those with and without polypectomy in the right colon. With adjusted odds ratios of 0.1 (0.1 to 0.2), 0.3 (0.2 to 0.5) and 0.4 (0.2 to 0.8) for patients with polypectomy less than 3, 3 to 5, and 6 to 10 years ago, risk reduction was particularly strong for left-sided CRC.

CONCLUSION

Extension of surveillance intervals to 5 years should be considered, even after detection and removal of high-risk polyps.