A systematic review on the effectiveness of clinician directed interventions to improve compliance to post polypectomy surveillance guidelines

Introduction Clinical practice guidelines recommend periodic colonoscopy surveillance following colorectal adenoma excision. Inappropriate use of post polypectomy surveillance is common and lead to improper resource utilisation.The aim of this review is to identify structured interventions which can affect post polypectomy surveillance practices and to evaluate the effectiveness of these various interventions in improving clinician adherence to post polypectomy surveillance guidelines. Methods A computerised search was performed to identify relevant studies between 1997 to November 2020. Two investigators identified eligible studies and extracted data independently. The quality of the included studies was assessed by the Newcastle-Ottawa risk of assessment scoring system. Results The search identified 5602 citations. Forty-one articles were retrieved for full text analysis and seven studies met the inclusion criteria. Compliance to PPS guidelines were higher following interventions which included medical education, specialist nurse coordinators facilitation, continuous quality improvement and clinical decision support systems. Conclusion This study demonstrates that medical education, specialist nurse coordinators, continuous quality improvement and clinical decision support systems are effective in improving clinicians’ compliance to post polypectomy surveillance guidelines and is associated with reduction in over- and underutilisation of colonoscopy surveillance resources.

Distinct Mutational Profile of Lynch Syndrome Colorectal Cancers Diagnosed under Regular Colonoscopy Surveillance

Regular colonoscopy even with short intervals does not prevent all colorectal cancers (CRC) in Lynch syndrome (LS). In the present study, we asked whether cancers detected under regular colonoscopy surveillance (incident cancers) are phenotypically different from cancers detected at first colonoscopy (prevalent cancers). We analyzed clinical, histological, immunological and mutational characteristics, including panel sequencing and high-throughput coding microsatellite (cMS) analysis, in 28 incident and 67 prevalent LS CRCs (n total = 95). Incident cancers presented with lower UICC and T stage compared to prevalent cancers (p < 0.0005). The majority of incident cancers (21/28) were detected after previous colonoscopy without any pathological findings. On the molecular level, incident cancers presented with a significantly lower KRAS codon 12/13 (1/23, 4.3% vs. 11/21, 52%; p = 0.0005) and pathogenic TP53 mutation frequency (0/17, 0% vs. 7/21, 33.3%; p = 0.0108,) compared to prevalent cancers; 10/17 (58.8%) incident cancers harbored one or more truncating APC mutations, all showing mutational signatures of mismatch repair (MMR) deficiency. The proportion of MMR deficiency-related mutational events was significantly higher in incident compared to prevalent CRC (p = 0.018). In conclusion, our study identifies a set of features indicative of biological differences between incident and prevalent cancers in LS, which should further be monitored in prospective LS screening studies to guide towards optimized prevention protocols.

913 An Audit of Colonoscopy Compliance Within A Screening Programme for Patients with A Family History of Colorectal Cancer (CRC)

Introduction Guidelines on the management of hereditary CRC were updated in 2019 and have led to more stringent use of surveillance colonoscopies. Patients with ‘family history’ (FH) CRC Surveillance programme at York Hospitals Trust were studied to assess compliance with colonoscopy recommendations. Method Current BSG/ACPGBI guidelines recommend biennial, quinquennial, one-off or no colonoscopy surveillance for patients with Lynch syndrome, and those deemed to have high, moderate, and average risks of developing hereditary cancer, respectively. Examination of electronic records and clinical notes were performed to determine if they were Lynch positive and/or if they could be assigned a risk category. Results Database of 227 patients, of which 14 were high, 61 moderate and 45 were low risk. 47 had Lynch syndrome. Compliance of colonoscopy was poor for patients with average and moderate FH risk (both 0%). Compliance was higher for patients with high risk of FH (50%) and those with Lynch syndrome (57%) Risk was indeterminate in 24 patients due to inadequate data therefore compliance could not be assessed. Conclusions A large proportion of patients with low to moderate ‘FH’ risk within our current surveillance programme had unnecessary colonoscopies. Stratification of patients into the appropriate risk categories optimizes the benefit from surveillance programmes.

Clinical validation of the SIMPLE classification for optical diagnosis of colorectal polyps

Background and study aims A novel endoscopic optical diagnosis classification system (SIMPLE) has recently been developed. This study aimed to evaluate the SIMPLE classification in a clinical cohort. Patients and methods All diminutive and small colorectal polyps found in a cohort of individuals undergoing screening, diagnostic, or surveillance colonoscopies underwent optical diagnosis using image-enhanced endoscopy (IEE) and the SIMPLE classification. The primary outcome was the agreement of surveillance intervals determined by optical diagnosis compared with pathology-based results for diminutive polyps. Secondary outcomes included the negative predictive value (NPV) for rectosigmoid adenomas, the percentage of pathology exams avoided, and the percentage of immediate surveillance interval recommendations. Analysis of optical diagnosis for polyps ≤ 10 mm was also performed. Results 399 patients (median age 62.6 years; 55.6 % female) were enrolled. For patients with at least one polyp ≤ 5 mm undergoing optical diagnosis, agreement with pathology-based surveillance intervals was 93.5 % (95 % confidence interval [CI] 91.4–95.6). The NPV for rectosigmoid adenomas was 86.7 % (95 %CI 77.5–93.2). When using optical diagnosis, pathology analysis could be avoided in 61.5 % (95 %CI 56.9–66.2) of diminutive polyps, and post-colonoscopy surveillance intervals could be given immediately to 70.9 % (95 %CI 66.5–75.4) of patients. For patients with at least one ≤ 10 mm polyp, agreement with pathology-based surveillance intervals was 92.7 % (95 %CI 89.7–95.1). NPV for rectosigmoid adenomas ≤ 10 mm was 85.1 % (95 %CI CI 76.3–91.6). Conclusions IEE with the SIMPLE classification achieved the quality benchmark for the resect and discard strategy; however, the NPV for rectosigmoid polyps requires improvement.