Colonoscopy Intervals Research Articles

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

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

Primary Care Provider Beliefs and Recommendations About Colorectal Cancer Screening in Four Healthcare Systems.

Primary care provider's (PCP) perceptions of colorectal cancer screening test effectiveness and their recommendations for testing intervals influence patient screening uptake. Few large studies have examined providers' perceptions and recommendations, including their alignment with evidence suggesting comparable test effectiveness and guideline recommendations for screening frequency. Providers (n = 1,281) within four healthcare systems completed a survey in 2017-2018 regarding their perceptions of test effectiveness and recommended intervals for colonoscopy and fecal immunochemical testing (FIT) for patients ages 40-49, 50-74, and ≥75 years. For patients 50-74 (screening eligible), 82.9% of providers rated colonoscopy as very effective versus 59.6% for FIT, and 26.3% rated colonoscopy as more effective than FIT. Also, for this age group, 77.9% recommended colonoscopy every 10 years and 92.4% recommended FIT annually. For patients ages 40-49 and ≥75, more than one-third of providers believed the tests were somewhat or very effective, although >80% did not routinely recommend screening by either test for these age groups. Provider screening test interval recommendations generally aligned with colorectal cancer guidelines; however, 25% of providers believed colonoscopy was more effective than FIT for mortality reduction, which differs from some modeling studies that suggest comparable effectiveness. The latter finding may have implications for health systems where FIT is the dominant screening strategy. Only one-third of providers reported believing these screening tests were effective in younger and older patients (i.e., <50 and ≥75 years). Evidence addressing these beliefs may be relevant if cancer screening recommendations are modified to include older and/or younger patients.

Colonoscopy Quality and Adherence to Postpolypectomy Surveillance Guidelines in an Underinsured Clinic System.

Background Delivery of high-quality colonoscopy and adherence to evidence-based surveillance guidelines is essential to a high-quality screening program, especially in safety net systems with limited resources. We sought to assess colonoscopy quality and ensure appropriate surveillance in a network of safety net practices. Methods We identified age-eligible patients ages 50-75 within a Federally Qualified Health Center (FQHC) clinic system with evidence of colonoscopy in preceding 10 years. We performed chart reviews to assess key aspects of colonoscopy quality: bowel preparation quality, evidence of cecal intubation, cecal withdrawal time, and the adenoma detection rate. We then utilized established guidelines to assess and revise surveillance colonoscopy intervals, determine whether appropriate surveillance had taken place, and schedule overdue patients as appropriate. Results Of 26,394 age-eligible patients, a total of 3,970 patients had evidence of prior colonoscopy and 1,709 charts were selected and reviewed. Mean age was 57, 54% identified as women and 51% identified as Hispanic. Of 1709 colonoscopies reviewed, 77% had data on bowel preparation, and of those, 85% had adequate preparation quality. Cecal intubation was documented in 89% of procedures. Adequate cecal withdrawal time was documented in 59% of those with documented cecal intubation. Overall adenoma detection rate was 42%. Initial surveillance interval was clearly stated in 72% (n = 1238) of procedures. Of these, initial recommended intervals were too short in 24.5% (n = 304) and too long in 3.6% (n = 45). A total of 132 patients (10.7%) were overdue for appropriate surveillance and were referred for follow-up colonoscopy. Conclusions Overall, the quality of screening colonoscopy was high, but reporting was incomplete. We found fair adherence to evidence-based surveillance guidelines, with significant opportunities to extend surveillance intervals and improve adherence to best practices.

S0279 Predicted Colorectal Cancer Outcomes With Reported Adherence to Follow-Up Colonoscopy After a Positive Stool-Based Test

INTRODUCTION: Colonoscopy (COL) non-adherence following a positive non-invasive colorectal cancer (CRC) screening test (e.g., multitarget stool DNA [mt-sDNA], fecal immunochemical test [FIT]) undermines the achievable benefits of screening. Given wide variations in the limited data reporting COL adherence after a positive non-invasive test, microsimulation modeling was used to estimate the clinical implications of this understudied input. METHODS: An average-risk US population cohort free of diagnosed CRC at age 40 that underwent triennial mt-sDNA or annual FIT screening from ages 50 to 75 was simulated using the validated CRC-AIM model. Three scenarios were modeled: (S1) assumed 100% adherence for initial screening and COL follow-up; (S2) reported adherence rates for initial mt-sDNA (71%) or FIT (43%) screening, with assumed 100% adherence to COL follow-up; and (S3) reported adherence rates for initial mt-sDNA or FIT screening and reported adherence rates for COL follow-up after positive mt-sDNA (73%) or FIT (47%). Sensitivity analyses were performed using 100% and reported adherence rates for mt-sDNA and FIT screening, with COL follow-up adherence ranging from 40%-100%. Patients without a COL follow-up were assumed to be non-adherent until CRC symptom onset. Outcomes for each scenario are per 1000 individuals. RESULTS: S1, S2, and S3 each yielded life-years gained (LYG) and reductions in CRC incidence and CRC mortality with either mt-sDNA or FIT screening vs no CRC screening (Table 1). Estimated LYG for mt-sDNA and FIT were 297 and 316 for S1, 284 and 245 for S2, and 203 and 113 for S3, respectively. Reductions in CRC incidence for mt-sDNA and FIT were 64% and 68% for S1, 61% and 50% for S2, and 43% and 23% for S3, respectively; reductions in CRC mortality were 72% and 76% for S1, 69% and 59% for S2, and 49% and 27% for S3, respectively. With assumed 100% adherence to mt-sDNA or FIT screening, the LYG transition was at 45% (LYG = 128) and 40% (LYG = 119) adherence for COL follow-up, respectively (Figure 1). At reported adherence for stool-tests, the additional LYG for mt-sDNA vs FIT ranged from 12 to 188 as follow-up COL adherence increased from 40% to 100% (Figure 2). CONCLUSION: These modeling analyses demonstrate that the inclusion of more realistic estimates for mt-sDNA, FIT, and COL follow-up adherence has substantial impact on the predicted outcomes. Using reported adherence rates, rather than assuming 100% adherence, mt-sDNA yields greater CRC screening benefits vs FIT.Table 1.: Predicted life-years gained (LYG), colorectal cancer (CRC) incidence reduction, and CRC mortality reduction for triennial multitarget stool DNA (mt-sDNA) and annual fecal immunochemical test (FIT) in 3 different adherence scenarios per 1000 individuals free of diagnosed colorectal cancer at age 40 and screened between 50–75 yearsFigure 1.: Percent difference in predicted life-years gained (LYG) per 1000 individuals assuming 100% adherence for triennial multitarget stool DNA (mt-sDNA) and annual fecal immunochemical test (FIT) at assumed adherence rate intervals for follow-up colonoscopy (COL) in individuals free of diagnosed colorectal cancer at age 40 and screened between 50–75 years. White boxes indicate 10% positive difference with mt-sDNA versus FIT. Dark gray boxes indicate >10% negative difference with mt-sDNA versus FIT.Figure 2.: Percent difference in predicted life-years gained (LYG) per 1000 individuals by reported adherence rates for triennial multitarget stool DNA (mt-sDNA) and annual fecal immunochemical test (FIT) at assumed adherence rate intervals for follow-up colonoscopy (COL) in individuals free of diagnosed colorectal cancer at age 40 and screened between 50–75 years. White boxes indicate 10% positive difference with mt-sDNA versus FIT. Dark gray boxes indicate >10% negative difference with mt-sDNA versus FIT.

S0322 Impact of Surveillance Colonoscopy Intervals in the Elderly Population Aged 75 Years and Above

S0322 Impact of Surveillance Colonoscopy Intervals in the Elderly Population Aged 75 Years and Above

S3127 Colonic Polyp Surveillance Guidelines Are Appropriate for Younger Patients Despite Having Higher Grade Polyps on Surveillance Colonoscopy Compared With Older Patients

INTRODUCTION: Over the past few decades, the incidence of colorectal cancer (CRC) in the United States has been decreasing for older patients (OP, ≥50 years old), but increasing for younger patients (YP, < 50 years old). Current colonic polyp surveillance guidelines are primarily based on data from OP and may not be appropriate to use in YP given the reported increase in rates of CRC in YP. Our aim was to investigate whether existing colonic polyp surveillance guidelines created for OP are appropriate for use in YP. METHODS: We performed a retrospective cohort study of patients from two academic medical centers. We generated Risk Stratification Groups (RSG) based on surveillance colonoscopy intervals recommended by the USMSTF for CRC (Table 1). To determine if current colonic polyp surveillance guidelines were appropriate, we measured whether a patient's RSG worsened from index to surveillance colonoscopy, signifying that higher grade polyps were found on the subsequent surveillance colonoscopy compared to the index colonoscopy. Changes in RSG between OP and YP was determined using a McNeamer Test. A multivariate analysis was used to determine independent risk factors for RSG worsening. RESULTS: 1892 patients were included in the study, comprising 1521 OP and 371 YP. At both index and surveillance colonoscopies, YP were more likely to be assigned to a lower RSG (lower grade polyps) compared with OP. However, a greater percentage of YP had their RSG worsen from index to surveillance colonoscopy compared with OP (32.34% vs 25.18%, P < 0.01) (Figure 1). YP were 1.63 times more likely to have RSG worsening compared with OP (95% CI = 1.2–2.2) after controlling for confounding factorsTable 1.: Risk Stratification of Patients Based on Surveillance Colonoscopy Time Recommendations from the US Multi-Society Task Force on Colorectal CancerFigure 1.: Risk Stratification Group (RSG) Changes Between Index and Surveillance Colonoscopies for Older Patients and Younger Patients.Figure 2.: Tier to Tier Risk Stratification Group (RSG) Changes Between Index and Surveillance Colonoscopies for Older Patients and Younger Patients.Most of the RSG worsening was from RSG 1 (normal colonoscopy or small hyperplastic polyps) to RSG 2 (1–2 small tubular adenomas) for both YP and OP (21.02% & 15.06%, respectively) (Figure 2). There were no cases of CRC found in YP and 5 cases of CRC diagnosed in OP on surveillance colonoscopy. CONCLUSION: In our cohort, RSG worsening between index and surveillance colonoscopy was more prevalent in YP compared with OP. Yet, most of the RSG worsening was not clinically meaningful in terms of progression to CRC. This would imply that for the sake of CRC prevention, current surveillance guidelines were indeed appropriate for YP in our cohort of patients. Further study is needed to determine why RSG worsening was higher in YP compared with OP and whether there is any clinical or practical significance to this RSG worsening.

Adoption of Multi-society Guidelines Facilitates Value-Based Reduction in Screening and Surveillance Colonoscopy Volume During COVID-19 Pandemic.

BackgroundCOVID-19 has caused a backlog of endoscopic procedures; colonoscopy must now be prioritized to those who would benefit most. We determined the proportion of screening and surveillance colonoscopies appropriate for rescheduling to a future year through strict adoption of US Multi-Society Task Force (USMSTF) guidelines.MethodsWe conducted a single-center observational study of patients scheduled for “open-access colonoscopy”—ordered by a primary care provider without being seen in gastroenterology clinic—over a 6-week period during the COVID-19 pandemic. Each chart was reviewed to appropriately assign a surveillance year per USMSTF guidelines including demographics, colonoscopy history and family history. When guidelines recommended a range of colonoscopy intervals, both a “conservative” and “liberal” guideline adherence were assessed.ResultsWe delayed 769 “open-access” screening or surveillance colonoscopies due to COVID-19. Between 14.8% (conservative) and 20.7% (liberal), colonoscopies were appropriate for rescheduling to a future year. Conversely, 415 (54.0%) patients were overdue for colonoscopy. Family history of CRC was associated with being scheduled too early for both screening (OR 3.9; CI 1.9–8.2) and surveillance colonoscopy (OR 2.6, CI 1.0–6.5). The most common reasons a colonoscopy was inappropriately scheduled this year were failure to use new surveillance colonoscopy intervals (28.9%), incorrectly applied family history guidelines (27.2%) and recommending early surveillance colonoscopy after recent normal colonoscopy (19.3%).ConclusionUp to one-fifth of patients scheduled for “open-access” colonoscopy can be rescheduled into a future year based on USMSTF guidelines. Rigorously applying guidelines could judiciously allocate colonoscopy resources as we recover from the COVID-19 pandemic.Electronic supplementary materialThe online version of this article (10.1007/s10620-020-06539-1) contains supplementary material, which is available to authorized users.

P-311 Low risk of advanced neoplasms for up to 20 years after negative colonoscopy: Potential for personalized follow-up screening intervals

Within ten years after a negative colonoscopy, advanced colorectal neoplasms (ADN) were shown to be rare. However, evidence on longer intervals is very sparse, and little is known on the potential of personalized screening intervals based on individual risk profiles. The objective of our study was to investigate the prevalence of ADN after longer colonoscopy intervals and the possible role of easy-to-collect factors for risk stratification.

A sensitive and quantitative multimodal blood test for the detection of colorectal adenomas and cancer: Correlation with size and number of polyps.

1555 Background: Colonoscopic polypectomy is the primary reason for declining colorectal cancer incidence and mortality. Epidemiological evidence has ordered the timing and risk of pre-cancerous adenomas, localized and invasive cancer along a 7-10 year continuum. The increased size and number of index polyps are correlated with an increased probability of progression to cancer and informs surveillance colonoscopies. Methods: A single-center, IRB-approved, prospective, blinded study was conducted at the VA Palo Alto Health Care System. Results for 354 patients with no prior diagnosis of CRC who were scheduled for colonoscopy are presented. Indications for colonoscopy were 86% asymptomatic and 14% with symptoms or positive-FIT. Patients had blood drawn immediately prior to colonoscopy. The test analyzes three biomarkers: circulating gastrointestinal epithelial cells (CEC), validated somatic mutations, and methylation (SEPTIN9) of cell-free DNA and uses incident risk to calculate a CMx Score, scaled from 0 to 100. Multivariate regression methods were used to assess the degree of association between the pre-defined CMx Scores and polyp sizes and number, adjusting for both DNA mutation and DNA methylation status. Results: There is a significant association between CMx Scores and polyp size (F value = 5.80, p-value = 0.017). DNA mutation (F value = 1.29, p-value = 0.263) and methylation status (F value = 0.34, p-value = 0.560) were non-significant. Similarly, there is a significant association between CMx Scores and number of polyps (F value = 23.71, p-value &lt; 0.0001). Again, DNA mutation (F value = 1.57, p-value = 0.210) and methylation status (F value = 1.34, p-value = 0.248) were non-significant. These results suggest that CMx Scores, which incorporate CEC, are providing predictive information of polyp sizes and number above and beyond DNA mutation and methylation status alone. Conclusions: A novel noninvasive multimodal blood-based assay that analyzes cell-free DNA for somatic mutations and methylation, CEC and integrates SEER incidence risk is significantly associated with polyp size and number. The opportunity to track progression and potentially inform colonoscopy interval is notable. [Table: see text]

Use of Polygenic Risk Scores to Select Screening Intervals After Negative Findings From Colonoscopy

Polygenic risk scores (PRSs) could help to define starting ages for colorectal cancer (CRC) screening. However, the role of PRS in determining the length of screening interval after negative findings from colonoscopies is unclear. We aimed to evaluate CRC risk according to PRS and time since last negative colonoscopy. We collected data from 3827 cases and 2641 CRC-free controls in a population-based case-control study in Germany. We constructed a polygenic risk scoring system, based on 90 single-nucleotide polymorphisms, associated with risk of CRC in people of European descent. Participants were classified as having low, medium, or high genetic risk according to tertiles of PRSs among controls. Multiple logistic regression models were used to assess CRC risk according to PRS and time since last negative colonoscopy. Compared to individuals without colonoscopy in the low PRS category, a 42%-85% lower risk of CRC was observed for individuals who had a negative finding from colonoscopy within 10 years. Beyond 10 years after a negative finding from colonoscopy, significantly lower risk only persisted for the low and medium PRS groups, but not for the high PRS group. Adjusted odds ratios were 0.44 (95% CI, 0.29-0.68), 0.51 (95% CI, 0.34-0.77), and 0.85 (95% CI, 0.58-1.23) in the low, medium, and high PRS group, respectively. Within any time interval, risks were lower for distal than for proximal CRCs. Based on findings from a population-based case-control study, the recommended 10-year screening interval for colonoscopy may not need to be shortened among people with high PRSs, but could potentially be prolonged for people with low and medium PRSs. Studies are needed to address personalized time intervals for repeat colonoscopies in average-risk screening cohorts.

Narrow-band imaging and high-definition white-light endoscopy in patients with serrated lesions not fulfilling criteria for serrated polyposis syndrome: a randomized controlled trial with tandem colonoscopy

BackgroundIt is unknown whether narrow-band imaging (NBI) could be more effective than high-definition white-light endoscopy (HD-WLE) in detecting serrated lesions in patients with prior serrated lesions > 5 mm not completely fulfilling serrated polyposis syndrome (SPS) criteria.MethodsWe conducted a randomized, cross-over trial in consecutive patients with prior detection of at least one serrated polyp ≥10 mm or ≥ 3 serrated polyps larger than 5 mm, both proximal to the sigmoid colon. Five experienced endoscopists performed same-day tandem colonoscopies, with the order being randomized 1:1 to NBI—HD-WLE or HD-WLE—NBI. All tandem colonoscopies were performed by the same endoscopist.ResultsWe included 41 patients. Baseline characteristics were similar in the two cohorts: NBI—HD-WLE (n = 21) and HD-WLE—NBI (n = 20). No differences were observed in the serrated lesion detection rate of NBI versus HD-WLE: 47.4% versus 51.9% (OR 0.84, 95% CI: 0.37–1.91) for the first and second withdrawal, respectively. Equally, no differences were found in the polyp miss rate of NBI versus HD-WLE: 21.3% versus 26.1% (OR 0.77, 95% CI: 0.43–1.38). Follow-up colonoscopy in nine patients (22%) allowed them to be reclassified as having SPS.ConclusionsIn patients with previous serrated lesions, the serrated lesion detection rate was similar with NBI and HD-WLE. A shorter surveillance colonoscopy interval increases the detection of missed serrated polyps and could change the diagnosis of SPS in approximately one in every five patients.Trial registrationClinicalTrials.gov NCT02406547, registered on April 2, 2015.

Abnormal Stool Blood Tests and Colorectal Cancer Mortality in a Large United States Cohort

Abstract Our aim was to examine the association between fatal colorectal cancer (CRC) and time to colonoscopy among individuals who underwent diagnostic colonoscopy after abnormal stool blood test (SBT) in a cohort of United States Veterans. Methods: We performed a cohort study of Veterans aged 50–75 years, with an abnormal SBT using the Veterans Health Administration's (VA) national electronic health record data during the years 1999 and 2010. Colonoscopy receipt was ascertained using current procedural terminology codes after abnormal SBT. The study outcome, CRC death, was defined through National Death Index cause-specific mortality data. We followed patients through CRC-related death, other death, or until December 31, 2015. Multivariable Cox proportional hazards modeling was used to generate CRC-specific mortality hazard ratios (HRs) and 95% confidence intervals (CI) for 3-month colonoscopy intervals, with 3–6 months as the reference. Models were adjusted for age, sex, race/ethnicity, smoking, diabetes, body mass index, and Charlson Comorbidity Index. Results: We included 222,004 patients with abnormal SBTs; the average age was 63 with a standard deviation of 7.2 years, 97% were male, 72% were Non-Hispanic White and 20% were Black. Of the 222,004 patients, 69% completed diagnostic colonoscopy within 12 months of abnormal SBT, 4% were diagnosed with CRC, and 1% died of CRC specific death. Compared to patients with a colonoscopy at 3–6 months (standard of care), CRC-related mortality risk was significantly higher for patients with colonoscopies at 0–3 months (HR = 1.29; 95% CI, 1.14–1.47), 18–21 months (HR = 1.57; 95% CI, 1.19–2.06), and 21–24 months (HR = 1.46; 95% CI, 1.07–1.97). No significant increase in mortality risk was shown for 6–9 month, 9–12 month, 12–15 month, 15–18 months, and 24+ month intervals. Conclusion: Time to colonoscopy plays a significant role in CRC death after abnormal SBT. Compared to a colonoscopy performed during a 3–6-month window, a colonoscopy performed outside of the 15-month window had a higher risk for mortality. Given the impact of timely diagnostic colonoscopy on CRC mortality, development of interventions to increase timely diagnostic follow-up after abnormal SBT are essential to CRC outcome improvement.

A169 DEVELOPMENT OF A DECISION TOOL TO IMPROVE UTILISATION OF RECOMMENDED SURVEILLANCE INTERVALS FOR INDIVIDUALS WITH COLORECTAL POLYPS: A FOCUS GROUP ANALYSIS

Abstract Background Several studies have demonstrated a high utilization of colonoscopy at shorter and longer time intervals than guideline recommendations. Innovative methods are required to increase adherence to recommended timing. Aims 1) Explore current approaches used by endoscopist (EPs) and primary care providers (PCPs) to determine and communicate colonoscopy surveillance intervals (SI) between EPs, PCPs, and patients. 2) Obtain feedback for refining a decision tool to facilitate recommended SI. 3) Determine participant agreement of recommended SIs with current guidelines. Methods We conducted 4 focus groups (FGs); 3 FGs included EPs (n=12) and EPs in training (n=6); 1 FG included PCPs (n=4). FG questions explored use of guidelines, communication and follow-up practices with PCPs, EPs and patients, and challenges to follow-up. Participants were also asked for feedback about a prototype polyp SI decision tool that was developed using an algorithm synthesizing current Canadian Association of Gastroenterology, US Multisociety Task Force, and expert panel guidelines on SI. FGs were audio-recorded and transcribed for qualitative content analysis. FGs were analysed separately, then compared for similarities and differences. Finally, participants individually made interval recommendations for 7 common endoscopy scenarios. Responses were analyzed for agreement with the guidelines used to develop the decision tool. Results EPs reported not routinely referring to guidelines and were confident in their memory of the intervals although some reported checking occasionally. Many indicated they may use the tool in a web based or mobile application for more complicated scenarios, although some would never use it. Concerns regarding the tool included being up to date with research evidence and having required data to input on hand. PCPs reported the tool may be useful as a communication aid to involve patients in decision making. A challenge noted in all FGs was role confusion regarding communicating, tracking, and scheduling patients’ future procedures on time. Analysis of EPs (n=9) responses to the 7 scenarios showed that percent agreement with guidelines was low: 44% scored below 50% correct. Participants with the highest agreement scored 6/7; responses with the lowest agreement scored 0/7. The most common score was 3/7. Conclusions EPs appeared to be overconfident in their recommendations, but many were open to trying a website or mobile application decision tool to make evidence-based colonoscopy SI recommendations. Understanding, among PCPs and EPs, regarding responsibility for communicating results and scheduling follow-up surveillance for patients was inconsistent. Participant feedback informed development of a mobile application that is currently being pilot tested. Funding Agencies Research Manitoba

Endocytoscopy for the differential diagnosis of colorectal low-grade adenoma: a novel possibility for the “resect and discard” strategy

Endocytoscopy, a next-generation endoscopic system, facilitates observation at a maximum magnification of×520. To our knowledge, no study has reported high-precision diagnosis of colorectal low-grade adenoma, endoscopically. We aimed to reveal which endocytoscopic findings may be used as indicators of low-grade adenoma and to assess whether a "resect and discard" strategy using endocytoscopy is feasible. Lesions diagnosable with endocytoscopy were examined retrospectively between May 2005 and July 2017. A normal pit-like structure in endocytoscopic images was considered a normal pit (NP) sign and used as an indicator of low-grade adenoma. The primary outcome was the diagnostic accuracy of the NP sign for low-grade adenoma. We evaluated agreement rates between endocytoscopic and pathologic diagnosis for surveillance colonoscopy interval recommendation (SCIR) and performed a validation study to verify the agreement rates. For 748 lesions in 573 cases diagnosed as colorectal adenoma using endocytoscopy, the results were as follows: sensitivity of the NP sign for low-grade adenoma, 85.0%; specificity, 90.7%; positive predictive value, 96.6%; negative predictive value, 66.1%; accuracy, 86.4%; and positive likelihood ratio, 9.2 (P< .001). The agreement rate between endocytoscopic and pathologic diagnosis for SCIR was 94.4% (95% confidence interval [CI], 92.2%-96.1%; P< .001) under United States guidelines and 96.3% (95% CI, 94.5%-97.7%; P< .001) under European Union guidelines. All inter- and intraobserver agreement rates for expert and nonexpert endoscopists had κ values≥0.8 except one nonexpert pair. Endocytoscopy is an effective modality in determining the differential diagnosis of colorectal low-grade adenoma. (University Hospital Medical Information Network Clinical Trials database registration number: UMIN000018623.).

Survival by colon cancer stage and screening interval in Lynch syndrome: a prospective Lynch syndrome database report

BackgroundWe previously reported that in pathogenic mismatch repair (path_MMR) variant carriers, the incidence of colorectal cancer (CRC) was not reduced when colonoscopy was undertaken more frequently than once every 3 years, and that CRC stage and interval since last colonoscopy were not correlated.MethodsThe Prospective Lynch Syndrome Database (PLSD) that records outcomes of surveillance was examined to determine survival after colon cancer in relation to the time since previous colonoscopy and pathological stage. Only path_MMR variants scored by the InSiGHT variant database as class 4 or 5 (clinically actionable) were included in the analysis.ResultsNinety-nine path_MMR carriers had no cancer prior to or at first colonoscopy, but subsequently developed colon cancer. Among these, 96 were 65 years of age or younger at diagnosis, and included 77 path_MLH1, 17 path_MSH2, and 2 path_MSH6 carriers. The number of cancers detected within < 1.5, 1.5–2.5, 2.5–3.5 and at > 3.5 years after previous colonoscopy were 9, 43, 31 and 13, respectively. Of these, 2, 8, 4 and 3 were stage III, respectively, and only one stage IV (interval 2.5–3.5 years) disease. Ten-year crude survival after colon cancer were 93, 94 and 82% for stage I, II and III disease, respectively (p < 0.001). Ten-year crude survival when the last colonoscopy had been < 1.5, 1.5–2.5, 2.5–3.5 or > 3.5 years before diagnosis, was 89, 90, 90 and 92%, respectively (p = 0.91).ConclusionsIn path_MLH1 and path_MSH2 carriers, more advanced colon cancer stage was associated with poorer survival, whereas time since previous colonoscopy was not. Although the numbers are limited, together with our previously reported findings, these results may be in conflict with the view that follow-up of path_MMR variant carriers with colonoscopy intervals of less than 3 years provides significant benefit.

Does Colon Polyp Surveillance Improve Patient Outcomes?

Colon polyp surveillance now accounts for 25% of all colonoscopies performed. The evidence that colonoscopy surveillance reduces colorectal cancer (CRC) incidence or mortality is weak. The biology of the baseline lesions and quality of the baseline exam are two primary factors contributing to post-colonoscopy CRC. Prior recommendations for surveillance were based largely on the likelihood that patients with adenomas would develop advanced adenomas, a surrogate for CRC. There is now evidence that baseline colonoscopy findings are strongly associated with the risk of incidence or death from CRC. This evidence provides a basis for updated evidence-based recommendations for surveillance. In addition, there is also growing evidence that the quality of the baseline exam is an important predictor of the likelihood of developing post-colonoscopy CRC.

235 Variable Classification of Sessile Serrated Colon Polyps Among Pathologists in an Academic Center

INTRODUCTION: Sessile serrated polyps (SSPs) are candidate precursors of most interval colorectal cancers. These mostly right-sided lesions are easily missed, often incompletely removed, and may progress rapidly to malignancy. Accurate histologic distinction between precancerous and non-precancerous polyps is key to choosing appropriate intervals for colonoscopy. Among serrated polyps (SPs), precancerous SSPs are histologically similar to non-precancerous hyperplastic polyps, and disparity among expert pathologists is high with independent reviews of the same specimens. We assessed if this discrepancy would be reflected by significant variability in classification rates of HPs and SSPs among pathologists in a real-world academic clinical setting. METHODS: Using our Colonoscopy Quality Database (UCICQD) at a large academic medical center, we analyzed prospectively-collected data for all polyps removed and examined between 6/2012 and 12/2016. Polyp classification rates of each pathologist were calculated; association between pathologists and polyp classifications were assessed by unconditional logistic regression for multivariate analysis. The rate of classification of each pathologist was analyzed as polyp size increased. RESULTS: Of 8,274 in polyps classified by 9 pathologists, 62.5% were described as adenomas. For 3,103 SPs, a mean of 22.0% was classified as SSPs. SSP classification rate varied among pathologists; a statistically significant association was found between pathologists and type of SP (HP vs SSP) (P &lt; 0.0001). The rate increased for all pathologists with increasing polyp size, although variability was high and pathologists maintained their relative positions when comparing SSPs/SPs between polyp sizes (1–3 mm vs &gt;4 mm), R = 0.8, P = 0.01. CONCLUSION: The SP classification rates of pathologists in the right colons are highly variable. The fraction of SPs classified as SSPs increases with polyp size but variability among pathologists remains high. This suggests that each pathologist is influenced by polyp size but has a different histologic threshold for distinguishing HPs and SSPs in the right colon. This data supports the idea that serrated polyps (HPs or SSPs) proximal to the sigmoid colon should be considered "surveillance relevant". This strategy will likely reduce interval cancer rates at the expense of additional colonoscopies in those with true HPs. Novel methodologies are needed to distinguish these morphologically similar but biologically distinct lesions.

547 Increasing Endoscopy Unit Efficiency: It's Time to Take Control

INTRODUCTION: Operational flow is an important factor in relation to efficiency in an endoscopy center. There are opportunities for improvement in efficiency while keeping the standards of quality. We performed a time flow analysis in our outpatient endoscopy center to identify workflow improvement opportunities. METHODS: We evaluated 616 patients who underwent EGD and colonoscopy. We analyzed preop prep time, procedure time, room turnover, recovery room time, total time in unit, and physician arrival time. These times were compared to efficiency benchmarks identified in the limited literature available. A process map was documented to illustrate patient flow and to assess redundancies and non-value added steps (Figure 1). Post-intervention data was collected on 381 patients. RESULTS: Pre-procedure nursing time exceeded benchmark intervals for both EGD and colonoscopy (Table 1). This was due to lack of documentation if the patient could not be reached during precall assessment 5 days prior to procedure requiring the nurse to obtain the information on the day of endoscopy. 2/3 of nurses did not have EMR access to be able to chart the medical history prior to patient arrival. In addition, IV was placed prior to the restroom visit delaying procedure start time while physician was ready to proceed. Doubles were allotted only 30 min block times and progressive delay was noticed increasing pre-procedure wait time. Physician start time was delayed 26% by an average of 12 min (Figure 2). This was due to clerical tasks, staff questions, and operational tasks. Encounter forms were reformatted to be user friendly for nursing documentation. All nurses were given EMR access in the event where patient was not reached prior to procedure. Pre-call assessment changed from 5 to 7 days prior to procedure to increase probability of reaching patients. Patients were offered restroom break prior to IV placement. Block times for doubles were extended from 30 to 45 minute block times . Recovery room delays with EGDs were attributed to oversedation by a single nurse anesthetist who was educated regarding propofol usage. Physician delays remained essentially unchanged (Figure 2). CONCLUSION: With our interventions, we reduced pre-procedure time by 8 mins for EGDs and 7 minutes for colonoscopy. We improved recovery room time. Delays related to physician behavior remain unchanged. Our next step is to address physician arrival times will be to post results of physician start times on a weekly basis at our endocenter.

2843 Lack of Knowledge About Follow-Up Colonoscopy in Patients With Biopsy Proven Advanced Colorectal Polyps: A Major Clinical and Medicolegal Challenge

INTRODUCTION: The most recent guidelines from the American College of Gastroenterology recommend that patients with biopsy proven advanced colorectal polyps undergo repeat surveillance colonoscopy at a minimum of three years following resection. The rationale is based on rates of recurrence and progression to colorectal cancer. In this report we quantitate the knowledge of patients with biopsy proven advanced colorectal polyps about if, and when, they need a repeat colonoscopy. METHODS: Methods: Written informed consents were obtained and brief telephone interviews conducted by trained interviewers among 84 patients with biopsy proven advanced colorectal polyps. In semi-structured questionnaires that included eleven questions the patients provided self-reports about their awareness of the need to have a repeat colonoscopy as well as the proper surveillance interval. RESULTS: Among the 84 patients, who ranged in age from 41-91 years, 24 (28.6%) were unaware of either the need for a repeat colonoscopy or the proper surveillance interval. These included 10 (12.0%) who were not even aware that they required a follow up colonoscopy and 14 (16.6%) who were unaware of the proper three year interval. CONCLUSION: Discussion: These data pose medical and legal challenges to clinicians to educate patients with biopsy proven advanced colorectal polyps about their need for repeat colonoscopy as well as the proper surveillance interval to reduce their risks of colorectal cancer. Specifically, without proper knowledge of the advanced colorectal polyp three year surveillance protocol, 28.6% of these high risk patients would have forgone or delayed the colonoscopy. With advances in technology and digitized medical records, clinicians may need to rely on a more objective and reproducible centralized database of past colonoscopy findings rather than self-reports. These clinical and medicolegal challenges may also be addressed, at least in part, by automated recalls that ensure there is a safety net to remind patients of their subsequent colonoscopy appointment. The success of these strategies will depend on meticulous attention by the clinician to ensure accurate data pertaining to guideline based appropriate surveillance intervals for colonoscopy. These strategies may also reduce any overutilization of colonoscopies. Of far greater import, the achievement of this goal may reduce morbidity and mortality from colorectal cancer in high risk patients with advanced colorectal polyps.

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

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). 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. 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. 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. 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.