Colonoscopy Surveillance Intervals Research Articles

Accuracy, Acceptability, and Application: Fecal Immunochemical Tests for Early Detection of Advanced Neoplasia in Colonoscopy-Based Surveillance

BackgroundThe fecal immunochemical test (FIT) is widely used in colorectal cancer (CRC) screening, but limited data exist for its application in individuals at above-average risk for CRC who complete surveillance colonoscopies.AimTo assess the accuracy, acceptability, and effectiveness of FIT in the interval between surveillance colonoscopies, for predicting advanced neoplasia (advanced adenoma or CRC) at the next colonoscopy.MethodsIndividuals enrolled in an Australian surveillance program were included. Diagnostic accuracy was determined for 614 individuals completing a two-sample FIT (OC-Sensor) ≤ 3 months preceding surveillance colonoscopy. 386 Individuals were surveyed to assess acceptability of interval FIT. Additionally, a retrospective analysis was performed on 7331 individuals offered interval FIT between colonoscopies, where a positive FIT (≥ 20 µg hemoglobin/g feces) triggered an early colonoscopy. Associations between interval FIT results and advanced neoplasia were determined using regression analysis.ResultsFIT detected CRC and advanced adenoma with sensitivities of 60.0% (3/5) and 27.1% (35/129), respectively. Most (89.1%, 344/386) survey respondents preferred completing interval FIT every 1–2 years. The detection rate of interval FIT for advanced neoplasia decreased with increasing FIT completion. Individuals returning a positive FIT had a higher risk of advanced neoplasia than those who did not complete FIT. Positive interval FIT reduced time-to-diagnosis for CRC and advanced adenoma by a median of 30 and 20 months, respectively.ConclusionInterval FIT was well accepted and enabled earlier detection of advanced neoplasia in individuals at above-average risk of CRC. Given that interval FIT predicts advanced neoplasia, it may be used to personalize surveillance colonoscopy intervals.

Early-onset Colorectal Cancer Patients Do Not Require Shorter Intervals for Post-surgical Surveillance Colonoscopy

Early-onset colorectal cancer (EO-CRC), diagnosed before age 50, is rising in incidence worldwide. Although post-surgical colonoscopy surveillance strategies exist, appropriate intervals in EO-CRC remain elusive, as long-term surveillance outcomes remain scant. We sought to compare findings of surveillance colonoscopies of EO-CRC with patients with average onset colorectal cancer (AO-CRC) to help define surveillance outcomes in these groups. Single-institution retrospective chart review identified EO-CRC and AO-CRC patients with colonoscopy and no evidence of disease. Surveillance intervals and time to development of advanced neoplasia (CRC and advanced polyps [adenoma/sessile serrated]) were examined. For each group, 3 serial surveillance colonoscopies were evaluated. Statistical analyses were performed utilizing log-ranked Kaplan-Meier method and Cox proportional hazards. A total of 1259 patients with CRC were identified, with 612 and 647 patients in the EO-CRC and AO-CRC groups, respectively. Compared with patients with AO-CRC, patients with EO-CRC had a 29% decreased risk of developing advanced neoplasia from time of initial surgery to first surveillance colonoscopy (hazard ratio, 0.71; 95% confidence interval, 0.52-1.0). Average follow-up time from surgical resection to first surveillance colonoscopy was 12.6 months for both cohorts. Overall surveillance findings differed between cohorts (P= .003), and patients with EO-CRC were found to have less advanced neoplasia compared with their counterparts with AO-CRC (12.4% vs 16.0%, respectively). Subsequent colonoscopies found that, while patients with EO-CRC returned for follow-up surveillance colonoscopy earlier than patients with AO-CRC, the EO-CRC cohort did not have more advanced neoplasia nor non-advanced adenomas. Patients with EO-CRC do not have an increased risk of advanced neoplasia compared with patients with AO-CRC and therefore do not require more frequent colonoscopy surveillance than current guidelines recommend.

Single-center experience with intraprocedural cleansing system to improve inadequate bowel preparation during colonoscopy

Inadequate bowel preparation is common despite various preprocedure interventions. There is a need for an intervention at the time of colonoscopy to combat poor preparation. In this retrospective, observational study of 46 patients, we evaluated the clinical efficacy and feasibility of implementing the third generation of the Pure-Vu EVS System, a US Food and Drug Administration-cleared over-the-scope-based intraprocedural cleansing device, into our practice at the Minneapolis VA Medical Center (Minneapolis, Minnesota, United States). To study clinical efficacy, we measured bowel preparation adequacy before and after using the device, as measured by the Boston Bowel Preparation Score, and reviewed colonoscopy surveillance interval recommendations. Technical success and feasibility of using the device were measured by procedure success rates and duration. We found that BBPS scores increased from 4.4 to 7.9 when using the device. Technical success was achieved 78.3% of the time (36/46 cases). Median colonoscopy duration was 46 minutes, although there was a trend toward shorter procedures over time. This is the first clinical evaluation of the third generation of an intraprocedural cleansing device. We found the device efficacious and easy to use with low procedure failure rates, but it does come with a learning curve. We suspect that adoption of this device mutually will benefit patients and health systems with the potential to improve resource utilization.

Risk of colorectal cancer in patients with primary sclerosing cholangitis and concomitant inflammatory bowel disease compared with primary sclerosing cholangitis only.

Primary sclerosing cholangitis (PSC) increases the risk of colorectal cancer (CRC) in inflammatory bowel disease (IBD) patients; however, there is a paucity of literature to suggest PSC alone as an independent risk factor for CRC. We aimed to determine if PSC is an independent risk factor for CRC in a large tertiary care medical center. Optimizing screening intervals is of great importance, given the burden and risks associated with a lifetime of colonoscopy screening. This retrospective cohort study consists of patients diagnosed with PSC preceding IBD (PSC-IBD) and PSC-only before January 6, 2023 from a large, tertiary, academic medical center. Patients diagnosed with IBD concurrently or before PSC were excluded to reduce IBD's impact on CRC risk. Demographic data and colonoscopy findings were collected and assessed. Overall, 140 patients from all NYU Langone Health clinical settings were included. Patients with PSC-IBD were more likely to be diagnosed with CRC (23.3% vs. 1.8%, p<0.01) and either low-grade or uncharacterized dysplasia (16.7% vs. 0.0%, p<0.01) compared with those with PSC-only. Among PSC-only patients, the estimated CRC risk was significantly elevated compared with that expected of the standard NYU Langone population (SIR 9.2, 95% CI 1.1, 33.2). Our study revealed a significantly heightened CRC risk in PSC-IBD patients compared with those with PSC-only. Importantly, individuals with PSC-only also face a greater CRC risk compared with the general population. Individuals with PSC-alone may require extended screening and surveillance colonoscopy intervals compared with those with PSC-IBD, yet still require more frequent monitoring than screening guidelines recommend for the general population.

Clinicopathological features of post-colonoscopy colorectal cancer in patients with Japanese Lynch syndrome: A multicentric retrospective observational study.

79 Background: Due to the high incidence of heterochronic and concurrent colorectal cancer in Lynch syndrome (LS), colonoscopic surveillance is recommended in Japan every 1-2 years. Even with regular colonoscopic surveillance, post-colonoscopy colorectal cancer (PCCRC) often occurs in the intervals between surveillance, but there are currently no reports of the details of PCCRC in LS in Japan. Methods: Of 1756 colonoscopies performed between 2009 and 2018 in 316 patients with a diagnosis of LS confirmed by genetic testing who were enrolled in a nationwide, Japanese, multicentric study conducted by the Committee of Hereditary Colorectal Cancer of the Japanese Society for Cancer and Rectum, 1203 colonoscopies in 256 patients were assessed to determine the clinicopathological characteristics of PCCRC, after including cases of first-time surveillance, previously untreated lesions, and inadequate pretreatment. Then, the incidence of PCCRC was compared between patients with a median surveillance colonoscopy interval &lt; 12 months (group A) and &gt; 12 months (group B). Results: There were 49 cases of PCCRC with a total of 84 lesions. The number of lesions per tumor depth was 66, one, five, seven, four, and one for pTis, pT1, pT1a, pT1b, pT2, and pT3, respectively. Two (2.4%), 20 (23.8%), 21 (25%), four (4.8%), 18 (21.4%), and 19 (22.6%) lesions were localized in the cecum, ascending colon, transverse colon, descending colon, sigmoid colon, and rectum, respectively. In pTis-pT1b, the macroscopic type was 0-IIa in 33 lesions (41.8%), 0-IIc in four lesions (5.1%), 0-IIa+IIc in five lesions (6.3%), 0-IIb in one lesion (1.3%), 0-Is in 15 lesions (19%), 0-Ip in one lesion (1.3%), 0-Isp in 16 lesions (20.3%), and unknown in four lesions. In pT1b-pT3, seven lesions (63.6%) were smaller than 20 mm. In terms of the median interval between surveillance colonoscopies, 130 patients had a median interval &lt; 12 months (group A), and 126 patients had a median interval &gt; 12 months (group B). In groups A and B, PCCRC, metachronous cases, simultaneous cases, and depths than pT1b were observed in 29 (22%) and 20 (16%) cases (p=0.21); 14 (11%) and two (1.6%) cases (p=0.006); six (4.6%) and one (0.8%) case (p=0.22), and six (4.6%) and four (3.2%) cases (p=1), respectively. Conclusions: In PCCRC in Lynch syndrome, invasive carcinomas &lt; 2 cm should be noted. In addition, a surveillance interval of 12 months may be insufficient in patients with LS. Thus, further investigation is warranted.

Randomized Trial of Patient Outreach Approaches to De-implement Outdated Colonoscopy Surveillance Intervals

Guidelines now recommend patients with low-risk adenomas receive colonoscopy surveillance in 7-10 years and those with the previously recommended 5-year interval be re-evaluated. We tested 3 outreach approaches for transitioning patients to the 10-year interval recommendation. This was a 3-arm pragmatic randomized trial comparing telephone, secure messaging, and mailed letter outreach. The setting was Kaiser Permanente Northern California, a large integrated healthcare system. Participants were patients 54-70 years of age with 1-2 small (<10 mm) tubular adenomas at baseline colonoscopy, due for 5-year surveillance in 2022, without high-risk conditions, and with access to all 3 outreach modalities. Patients were randomly assigned to the outreach arm (telephone [n= 200], secure message [n= 203], and mailed letter [n= 201]) stratified by age, sex, and race/ethnicity. Outreach in each arm was performed by trained medical assistants (unblinded) communicating in English with 1 reminder attempt at 2-4 weeks. Participants could change their assigned interval to 10 years or continue their planned 5-year interval. Sixty-day response rates were higher for telephone (64.5%) and secure messaging outreach (51.7%) vs mailed letter (31.3%). Also, more patients adopted the 10-year surveillance interval in the telephone (37.0%) and secure messaging arms (32.0%) compared with mailed letter (18.9%) and rate differences were significant for telephone (18.1%; 97.5% confidence interval: 8.3%-27.9%) and secure message outreach (13.1%; 97.5% confidence interval: 3.5%-22.7%) vs mailed letter outreach. Telephone and secure messaging were more effective than mailed letter outreach for de-implementing outdated colonoscopy surveillance recommendations among individuals with a history of low-risk adenomas in an integrated healthcare setting. (ClinicalTrials.gov, Number: NCT05389397).

Representation of Racial Minorities in the United States Colonoscopy Surveillance Interval Guidelines.

Clinical guidelines should ideally be formulated from data representative of the population they are applicable to; however, historically, studies have disproportionally enrolled non-Hispanic White (NHW) patients, leading to potential inequities in care for minority groups. Our study aims to evaluate the extent to which racial minorities were represented in the United States Colorectal Cancer Surveillance Guidelines. We reviewed US guidelines between 1997 and 2020 and all identified studies cited by recommendations for surveillance after a baseline colonoscopy with no polyps, adenomas, sessile serrated polyps, and hyperplastic polyps. We analyzed the proportion of studies reporting race, and among these studies, we calculated the racial distribution of patients and compared the proportion of Non-NHW patients between each subtype. For all guidelines, we reviewed 75 studies encompassing 9,309,955 patients. Race was reported in 24% of studies and 14% of total patients. Non-NHW comprised 43% of patients in studies for normal colonoscopies, compared with 9% for adenomas, 22% for sessile serrated polyps, and 15% for hyperplastic polyps. For the 2020 guidelines, we reviewed 33 studies encompassing 5,930,722 patients. Race was reported in 15% of studies and 21% of total patients. Non-NHW comprised 43% of patients in studies for normal colonoscopies, compared with 9% for tubular adenomas. Race was not cited for any other 2020 guideline. Racial minorities are significantly underrepresented in US Colorectal Cancer Surveillance Guidelines, which may contribute to disparities in care. Future studies should prioritize enrolling a diverse patient population to provide data that accurately reflects their population.

OPTIMIZING TIMING OF FOLLOW-UP COLONOSCOPY: A PILOT CLUSTER RANDOMIZED TRIAL OF A KNOWLEDGE TRANSLATION TOOL.

Endoscopists have low adherence to guideline recommended colonoscopy surveillance intervals. We performed a cluster randomized single-blind pilot trial in Winnipeg, Canada to assess the effectiveness of a newly developed digital application tool which computes guideline recommended follow-up intervals. Participant endoscopists were randomized to either receive access to the digital application (intervention group) or not receive access (control group). Pathology reports and final recommendations for colonoscopies performed in the 1-4 months before randomization and 3-7 months post-randomization were extracted. Generalized estimating equation models were used to determine if the access to the digital application predicted guideline congruence. We included 15 endoscopists in the intervention group and 14 in the control group (out of 42 eligible endoscopists in the city), with 343 patients undergoing colonoscopy before randomization, and 311 post-randomization. Endoscopists who received the application made guideline-congruent recommendations 67.6% of the time prior to randomization and 76.1% of the time after randomization. Endoscopists in the control group made guideline- congruent recommendations 72.4% and 72.9% of the time pre- and post-randomization, respectively. Endoscopists in the intervention group trended to have an increase in guideline adherence comparing post to pre-intervention (OR:1.50, 95%CI 0.82-2.74). In contrast, the control group had no change in guideline adherence (OR:1.07, 95%CI 0.50-2.29). Endoscopists in the intervention group with less than median guideline congruence pre-randomization had a significant increase in guideline congruent recommendations post-randomization. An application that provides colonoscopy surveillance intervals may help endoscopists with guideline congruence, especially those with a lower pre-intervention congruence with guideline recommendations. (ClincialTrials.gov number, NCT04889352).

S1687 De-Implementation of Outdated Colonoscopy Surveillance Interval Recommendations Among Patients With Low-Risk Adenomas (DESIRE)

S1687 De-Implementation of Outdated Colonoscopy Surveillance Interval Recommendations Among Patients With Low-Risk Adenomas (DESIRE)

S363 Adherence to Recommended Surveillance Colonoscopy Intervals in Average Risk Patients: Experience From a Tertiary Care Center

S363 Adherence to Recommended Surveillance Colonoscopy Intervals in Average Risk Patients: Experience From a Tertiary Care Center

Adoption of colonoscopy surveillance intervals in subjects who received polypectomy in southern China: A cost-effectiveness analysis.

We aimed to evaluate the cost-effectiveness of different colonoscopy intervals among average-risk (5 vs 10years) and high-risk (1 vs 3years) southern Chinese populations. We constructed a Markov model with a hypothetical population of 100000 individuals aged 50-85years. Average risk was defined as 1-2 non-advanced adenomas (tubular adenoma sized <10mm without high-grade dysplasia). High risk was defined as ≥3 non-advanced adenomas or any advanced adenoma (adenoma sized ≥10mm, with high-grade dysplasia, or with villous/tubulovillous histology). Three strategies were compared: a 5/1 strategy (average-risk subjects: 5-year interval; high-risk subjects: 1-year interval), a 10/3 strategy, and a control strategy (a 10/10 strategy). Costs (US dollar), quality-adjusted-life-years, incremental cost-effectiveness ratio, and net health benefit were calculated. If the incremental cost-effectiveness ratio of one strategy against another was less than willingness-to-pay ($24302 US/quality-adjusted-life-years), the strategy was more cost-effective than another. Compared with the 10/3 strategy, the 5/1 strategy involved more costs and effects (incremental cost-effectiveness ratio=$40044 US/quality-adjusted life-years). When the 10/10 strategy was regarded as the control, the 5/1 strategy had a higher incremental cost-effectiveness ratio than the 10/3 strategy ($26056 vs $10344 US/quality-adjusted life-years). Furthermore, the 10/3 strategy had the highest net health benefit. A 10/3 interval was more cost-effective than a 5/1 interval. From an economic perspective, our findings supported a 10-year interval for average-risk individuals and a 3-year interval for high-risk subjects. The findings could help form the optimal colonoscopy interval for average-risk and high-risk patients.

FIT for purpose: study protocol for a randomized controlled trial to personalize surveillance colonoscopy for individuals at elevated risk of colorectal cancer

PurposeThere is increasing demand for colorectal cancer (CRC) surveillance, but healthcare capacity is limited. The burden on colonoscopy resources could be reduced by personalizing surveillance frequency using the fecal immunochemical test (FIT). This study will determine the safety, cost-effectiveness, and patient acceptance of using FIT to extend surveillance colonoscopy intervals for individuals at elevated risk of CRC.MethodsThis multicenter, prospective, randomized controlled trial will invite participants who are scheduled for surveillance colonoscopy (due to a personal history of adenomas or a family history of CRC) and who have returned a low fecal hemoglobin (< 2 μg Hb/g feces; F-Hb) using a two-sample FIT (OC Sensor, Eiken Chemical Company) in the prior 3 years. A total of 1344 individuals will be randomized to either surveillance colonoscopy as scheduled or delayed by 1 or 2 years for individuals originally recommended a 3- or 5-year surveillance interval, respectively. The primary endpoint is incidence of advanced neoplasia (advanced adenoma and/or CRC). Secondary endpoints include cost-effectiveness and consumer acceptability of extending surveillance intervals, determined using surveys and discrete choice experiments.ConclusionThis study will establish the safety, cost-effectiveness, and acceptability of utilizing a low FIT Hb result to extend colonoscopy surveillance intervals in a cohort at elevated risk for CRC. This personalized approach to CRC surveillance will lead to a reduction in unnecessary colonoscopies, increases in healthcare savings, and a better patient experience. Trial registrationRegistration was approved on December 9, 2019 with the Australian New Zealand Clinical Trials Registry ANZCTR 12619001743156.

What Is the Risk? Epidemiology and Evidence for Surveillance Regimens.

Patients with inflammatory bowel disease (IBD) have increased risk of colorectal cancer (CRC). The risk for CRC is positively correlated to the duration of disease, extent of colonic involvement, and severity of inflammation. After 8 to 10 years of IBD diagnosis, the risk for CRC rises substantially and screening colonoscopy is recommended. Surveillance colonoscopy interval ranges from 1 to 5 years depending on patient and disease-specific risk factors. IBD patients with high risk factors such as having concomitant primary sclerosing cholangitis, moderate-to-severe inflammation, first-degree relative with CRC at early age, or history of invisible dysplasia or high-risk visible dysplasia should undergo surveillance colonoscopy in 1 year. Meanwhile, those with minimal colonic involvement or ≥2 consecutive unremarkable examinations while in continuous remission may consider extending the surveillance interval to 5 years. Advance in colonoscopy technique such as chromoendoscopy using dyes and/or image digital processing (virtual chromoendoscopy) may enhance dysplasia detection and is the preferred method for IBD surveillance. In the era of high-definition colonoscope, the practice of obtaining extensive biopsies throughout the colon remains controversial but is generally recommended to improve the detection rate of invisible dysplasia. Endoscopic surveillance in IBD has been shown to result in earlier detection of CRC and improved prognosis.

The Impacts of Computer-Aided Detection of Colorectal Polyps on Subsequent Colonoscopy Surveillance Intervals: Simulation Study.

Computer-aided detection (CADe) of colorectal polyps has been shown to increase adenoma detection rates, which would potentially shorten subsequent surveillance intervals. The purpose of this study is to simulate the potential changes in subsequent colonoscopy surveillance intervals after the application of CADe in a large cohort of patients. We simulated the projected increase in polyp and adenoma detection by universal CADe application in our patients who had undergone colonoscopy with complete endoscopic and histological findings between 2016 and 2020. The simulation was based on bootstrapping the published performance of CADe. The corresponding changes in surveillance intervals for each patient, as recommended by the US Multi-Society Task Force on Colorectal Cancer (USMSTF) or the European Society of Gastrointestinal Endoscopy (ESGE), were determined after the CADe was determined. A total of 3735 patients who had undergone colonoscopy were included. Based on the simulated CADe effect, the application of CADe would result in 19.1% (n=714) and 1.9% (n=71) of patients having shorter surveillance intervals, according to the USMSTF and ESGE guidelines, respectively. In particular, all (or 2.7% (n=101) of the total) patients who were originally scheduled to have 3-5 years of surveillance would have their surveillance intervals shortened to 3 years, following the USMSTF guidelines. The changes in this group of patients were largely attributed to an increase in the number of adenomas (n=75, 74%) rather than serrated lesions being detected. Widespread adoption of CADe would inevitably increase the demand for surveillance colonoscopies with the shortening of original surveillance intervals, particularly following the current USMSTF guideline.

Abstract P009: Plasma concentrations of multiple oxysterols and risk of colorectal adenomas

Abstract Oxysterols are metabolites of cholesterol and intermediates in pathways for primary bile acid synthesis that regulate homeostasis of cholesterol, fatty acids, and glucose by interacting with widely expressed nuclear receptors. These metabolites are generated throughout the body, either enzymatically or from oxidative stress, and are detectable in peripheral circulation at concentrations much lower than total cholesterol. We previously reported that circulating 27-hydroxycholesterol (27-OHC), the most abundant oxysterol in circulation and an endogenous selective estrogen receptor modulator, may be a risk factor for colorectal adenomas. Here, we report on four other circulating oxysterols: 25-hydroxycholesterol (25-OHC), 24(S)-hydroxycholesterol (24(S)-OHC), 7ɑ-hydroxycholesterol (7ɑ-OHC), and 4β-hydroxycholesterol (4β-OHC). We used high-sensitivity liquid chromatography-mass spectrometry to measure oxysterol concentrations in fasting plasma collected at baseline from 1,440 participants of the Vitamin D/Calcium Polyp Prevention Study, a completed randomized clinical trial that enrolled men and women recently diagnosed with colorectal adenomas with follow-up timed to colonoscopic surveillance intervals. Advanced adenomas were defined as tubulovillous or villous lesions, ≥1 cm in diameter, with high-grade dysplasia, or invasive adenocarcinoma. Risk ratios (RR) with 95% confidence intervals (CI) of new colorectal adenomas occurring during follow-up were estimated using repeated-measures log-linear regression for log-transformed circulating oxysterols. Primary analyses adjusted for multiple potential confounding factors and the five circulating oxysterols simultaneously, including 27-OHC. One geometric standard deviation (SD) higher circulating 7ɑ-OHC at the time of initial adenoma diagnosis was associated with 9% and 20% higher subsequent risk of any adenomas and advanced adenomas, respectively (RR of any adenomas per SD circulating 7ɑ-OHC, 1.09; 95% CI, 1.03-1.15 and RR of advanced adenomas, 1.20; 95% CI, 1.04-1.39). The positive association with adenoma risk that we previously reported for circulating 27-OHC persisted controlling for the other oxysterols including 7ɑ-OHC (RR of any adenomas per SD circulating 27-OHC 1.07; 95% CI, 0.99-1.15 and RR of advanced adenomas, 1.23; 95% CI, 1.03-1.48). No statistically significant associations were observed for circulating 25-OHC, 24(S)-OHC, and 4β-OHC. We conclude that circulating 7ɑ-OHC and 27-OHC may be independently associated with colorectal adenoma risk. Given these two oxysterols are the initial products of the classic (neutral) and alternative (acidic) pathways for primary bile acid synthesis, respectively, our findings provide additional evidence in support of a role for bile acids in the development of colorectal neoplasia. Novel colorectal cancer prevention strategies may target oxysterol formation. Citation Format: Michael N. Passarelli, Bonne M. Thompson, Jeffrey G. McDonald, Thomas J. Palys, Judy R. Rees, Elizabeth L. Barry, John A. Baron. Plasma concentrations of multiple oxysterols and risk of colorectal adenomas. [abstract]. In: Proceedings of the AACR Special Conference: Precision Prevention, Early Detection, and Interception of Cancer; 2022 Nov 17-19; Austin, TX. Philadelphia (PA): AACR; Can Prev Res 2023;16(1 Suppl): Abstract nr P009.

Bowel cleansing efficacy of 1L NER1006versus macrogol and 3L polyethylene glycol using split-dose administration.

Colonoscopies are an important diagnostic technique in the detection of colorectal cancer and colonic disease. Adequate examination is dependent on the degree of mucosal visibility, with poor cleansing impeding the detection of neoplasms. These patients require shorter colonoscopy surveillance intervals, longer hospital stays, and increased healthcare costs-rendering a screening colonoscopy cost-ineffective. In Australia and the Gold Coast Hospital and Health Service (GCHHS), macrogol and 3L of polyethylene glycol are the preferred regimen given its safety profile and efficacy. Yet, little is known locally about the use of the new low-volume bowel preparation NER1006 (Plenvu) given its recent registration with the Therapeutic Goods of Australia (TGA). The primary outcome assessed the bowel cleansing efficacy of NER1006 compared with 7 days of macrogol and 3L of polyethylene glycol using the Boston Bowel Preparation Scale (BBPS), while also assessing the influence of notable patient characteristics such as age, gender, body mass index (BMI), and the patients Charlson comorbidity index (CCI). Secondary outcomes assessed the polyp detection rate and procedural factors including cecal intubation, scope withdrawal time, and rebooking rates. Data from all patients who underwent an outpatient colonoscopy procedure at GCHHS between 1 July 2020 and 30 September 2020 were analyzed. Patients were aged 50-74 years of age and were referred for a screening colonoscopy due to a positive fecal occult blood test (FOBT) result from the National Bowel Cancer Screening Program. Of the 238 patients who met the inclusion criteria, 108 patients received NER1006 and 130 patients received macrogol and 3L polyethylene glycol. NER1006 achieved superior overall (P< 0.001) and right-sided colon cleansing (P= 0.016). There was an even distribution of males and females (P= 0.118), the mean age of both cohorts was <65 years of age. The macrogol and 3L polyethylene glycol group had a statistically higher BMI (P< 0.001) and CCI (P< 0.001). Cecal intubation success was achieved in both cohorts (≥95%) and scope withdrawal time was ≥6min, polyp detection was non-superior (P= 0.824), but superior in NER1006 when BBPS ≥6 (P= 0.002). Rebooking rates were significantly lower in the NER1006 group (P= 0.013). This study demonstrated that NER1006 was superior in terms of overall and right-sided bowel cleansing as a primary endpoint. Patient factors demonstrated to be independent predictors of inadequate bowel preparation. Future studies should aim to explore the safety and tolerability of NER1006 while also assessing the bowel cleansing effectiveness in patients with a high BMI and comorbidity index.

S271 Representation of Racial Minorities in the United States Colonoscopy Surveillance Interval Guidelines

Introduction: Clinical guidelines should ideally be formulated from data representative of the population they are applicable to. However, historically many studies have had disproportionately high rates of white patient enrollment, which could lead to inequities in care for racial minorities. In this study, we examined the degree to which racial minorities were represented in the US colonoscopy surveillance guidelines. Methods: We reviewed US guidelines between 1997 and 2020 and identified all studies cited by recommendations for surveillance after a baseline colonoscopy with no polyps, adenomas, sessile serrated polyps (SSPs), and hyperplastic polyps (HPs). Each study within a meta-analysis was analyzed separately. We compared the proportion of studies reporting race to the proportion which reported sex and family history of colorectal cancer (CRC). Among studies reporting race, we calculated both the median percentage of minorities and the aggregate racial distribution of patients. Statistical testing was performed via Fisher’s exact test, and Bonferroni correction was applied for multiple comparisons. Results: We reviewed a total of 77 studies, of which 35 were from the US (Table). 18 studies (23%) reported race, compared to 73 studies (95%) which reported sex and 34 (44%) which reported family history of CRC (p < 0.001 and p = 0.006 respectively). All studies which reported race were US-based studies, thus 51% of US-based studies reported race. Among studies that reported race, the median number of minorities was 15% of the study population, ranging from a low of 12% for studies on adenomas and HPs to 30% for studies on SSPs. In aggregate, non-white patients comprised 43% of the study population for normal colonoscopies but only 9% for adenomas, 22% of for SSPs, and 15% for HPs (p < 0.001 for all pairwise comparisons). Conclusion: Most studies on colonoscopy surveillance intervals, including approximately half of US-based studies, do not report the race of study participants. Among the studies that report racial data, minority patients are underrepresented in studies of adenoma, SSP, and HP surveillance intervals compared to the US population. Underrepresentation may lead to differences in outcomes being missed, thus future research should strive to include more data from these underrepresented groups. Table 1. - Reporting of Race and Racial Distribution of Patients among Studies of Colonoscopy Surveillance Intervals Abbreviations: CRC, colorectal cancer All studies(N=77) Normal colonoscopy(N=18) Adenomas(N=54) Sessile serrated polyps(N=7) Hyperplastic polyps(N=5) Number of studies which reported: Sex, n (%) 73 (95) 16 (89) 51 (94) 7 (100) 5 (100) Family history of CRC, n (%) 34 (44) 8 (44) 24 (44) 3 (43) 3 (60) Race, n (%) 18 (23) 3 (17) 12 (22) 2 (29) 2 (40) Percentage of minority patients, median (range)* 15 (4-43) 24 (15-43) 12 (4-36) 30 (16-43) 12 (10-15) Number of patients:* White, n (%) 752,876 (58) 710,149 (57) 26,672 (91) 3,053 (78) 13,341 (85) Black, n (%) 80,528 (6) 77,510 (6) 1,020 (4) 561 (14) 1,437 (9) Asian, n (%) 155,966 (12) 155,079 (12) 295 (1) 217 (6) 375 (2) Hispanic, n (%) 144,783 (11) 144,093 (12) 309 (1) 59 (2) 322 (2) Other, n (%) 167,082 (13) 165,955 (13) 954 (3) 19 (1) 154 (1) *Among studies which reported race.

Assessing the impact of the 2018 National Health and Medical Research Council polyp surveillance guidelines on compliance with surveillance intervals at two public hospitals.

Several studies have highlighted poor compliance with surveillance colonoscopy guidelines. The National Health and Medical Research Council (NHMRC) guidelines were revised in 2018 and were more complex than the previous iteration (2011). The aim of this study was to determine the impact of 2018 NHMRC polyp surveillance guidelines on compliance with colonoscopy surveillance intervals. A multicentre retrospective clinical audit was conducted between January 2020 and February 2021. Patients awaiting a colonoscopy for polyp surveillance at two public tertiary care hospitals in South Australia were included. Compliance rates of recommended polyp surveillance colonoscopy intervals after implementation of 2018 NHMRC guidelines were compared with 2011 NHMRC guidelines. The projected impact on colonoscopy bookings of the change in guideline intervals was modelled to 5 and 10 years, factoring in differences in compliance. Of 3996 patients awaiting colonoscopy services at two public hospitals in South Australia, 1984 patients (60% male, median age 61 years) were waitlisted for polyp surveillance. Overall compliance with surveillance guidelines was >60%. Implementation of the 2018 NHMRC guidelines significantly reduced compliance from 65.8% (2011 guidelines) to 50.8% (2018) (χ2 <0.001, OR 0.5). Modelling projections to 5 and 10 years demonstrated that application of the 2018 guidelines significantly increases the projected number of colonoscopy bookings per year. The revised 2018 NHMRC guidelines have resulted in significantly poorer compliance post-implementation, possibly due to their increased complexity. This has potential to increase the surveillance colonoscopy waiting list burden.

Comparative Effectiveness of Surveillance Colonoscopy Intervals on Colorectal Cancer Outcomes in a National Cohort of Patients with Inflammatory Bowel Disease

Surveillance colonoscopy is recommended to reduce colorectal cancer (CRC)-related morbidity and mortality in patients with inflammatory bowel disease (IBD). The comparative effectiveness of varying colonoscopy intervals on CRC outcomes among patients with IBD is unknown. We performed a retrospective cohort study of patients with confirmed CRC within a cohort of 77,824 patients with IBD during 2000 to 2015 in the National Veterans Health Administration. We examined the association between colonoscopy surveillance intervals on CRC stage, treatment, or all-cause and cancer-specific mortality. The interval of colonoscopy prior to CRC diagnosis was categorized as those performed within <1 year, 1 to 3 years, 3 to 5 years, or none within 5 years. Among 566 patients with CRC-IBD, most (69.4%) did not have colonoscopy within 5 years prior to CRC diagnosis, whereas 9.7% had colonoscopy within 1 year prior to diagnosis, 17.7% within 1 to 3 years, and 3.1% between 3 and 5 years. Compared with no surveillance, colonoscopy within 1 year (adjusted odds ratio, 0.40; 95% confidence interval [CI], 0.20-0.82), and 1 to 3 years (adjusted odds ratio, 0.56; 95% CI, 0.32-0.98) were less likely to be diagnosed at late stage. Regardless of IBD type and duration, colonoscopy within 1 year was associated with a lower all-cause mortality (adjusted hazard ratio, 0.56; 95% CI, 0.36-0.88). In a national cohort of patients with CRC-IBD, colonoscopy within 3 years prior to CRC diagnosis was associated with early tumor stage at diagnosis, and colonoscopy within 1 year was associated with a reduced all-cause mortality compared with no colonoscopy. Our findings support colonoscopy intervals of 1 to 3 years in patients with IBD to reduce late-stage CRC and all-cause mortality.

Younger Patients Do Not Develop More Advanced Polyps on Surveillance Colonoscopy Than Their Index Colonoscopy When Compared With Older Patients.

Colonic polyp surveillance guidelines are based on data from patients 50 and above. Given the recent lowering for colorectal cancer (CRC) screening to age 45, the aim of this study was to assess whether existing colonic polyp surveillance guidelines are appropriate to use in younger patients. We performed a retrospective cohort study of patients who underwent 2 colonoscopies within a 10-year period. Five Risk Stratification Groups (RSG) were developed based on surveillance colonoscopy interval times recommended by the US Multi-Society Task Force (USMSTF) on CRC, and changes in RSG from index to surveillance colonoscopy were compared between 3 age cohorts-those below 45, those 45 to 49, and those 50 and above. Further analysis was performed for patients whose RSG worsened from index to surveillance colonoscopy, as this was defined as an inappropriate surveillance interval. A total of 1895 patients were included in the final analysis. A multivariate regression model showed that a worsened RSG was not significantly associated with age group, both when comparing below 45 to those 50 and above [odds ratio (OR)=0.840, 95% confidence interval (CI): 0.504-1.399, P=0.50] and when comparing those 45 to 49 to those 50 and above (OR=1.416, 95% CI: 0.905-2.216, P=0.13). Only being female was found to be statistically associated with worsened RSG after controlling for other variables (OR=0.652, 95% CI: 0.486-0.875, P<0.01). Our study found that younger cohorts of patients, both below 45 and those 45 to 49, are not statistically more likely to develop more advanced polyps necessitating a shorter time to surveillance colonoscopy compared with patients 50 years and above. This finding supports using existing colonic polyp surveillance colonoscopy guidelines that were developed for patients 50 years and above in both patients below 45 and those 45 to 49 years old.