Colorectal Dysplasia Research Articles

Endoluminal Approaches for Colorectal Neoplasia in Inflammatory Bowel Disease, A Viable Alternative for Colectomy?

IntroductionEndoscopic resection of visible dysplastic lesions in patients with inflammatory bowel disease (IBD) provides an alternative to colectomy for management. Endoscopic techniques that can be used include endoscopic mucosal resection (EMR), endoscopic submucosal dissection (ESD), and a combined hybrid approach of ESD and EMR. These endoscopic treatments may allow organ preservation in patients with IBD. The aim of this study was to evaluate outcomes of endoscopic resection, including EMR, ESD and hybrid ESD/EMR, for the treatment of colorectal dysplasia in patients with IBD. MethodsWe performed a retrospective review of IBD patients who underwent endoscopic resection for colorectal dysplasia at our tertiary care center between 2014 to 2023. Patients were identified through a search of our endoscopy database. Medical records were reviewed to collect data on patient demographics, IBD history, details of endoscopic technique, procedural factors, final pathology results, and outcomes including recurrence of dysplasia. ResultsA total of 50 IBD patients underwent endoscopic resection, including 38 ESD, 11 hybrid ESD/EMR, and 1 EMR. Median age was 62 (IQR: 54-68) years and 34 (68%) were male. Median BMI was 27.6 (IQR: 24.8-31.7). Underlying diagnosis was ulcerative colitis in 33 (66%) and Crohn's disease in 17 (33%). Median disease duration was 27.5 years (IQR 8-30). Polyp locations were distributed as follows: right colon, rectum, left colon, transverse colon, and cecum, with 9 (18%) in each area. Median procedure time was 47.5minutes (IQR: 31.2-73.7). En bloc resection was achieved in 34 (68%) and piecemeal resection in 16 (32%). On pathology, median lesion size was 23.5 (IQR: 20.2-40) mm. High-grade dysplasia was found in 7 (14%) and low-grade dysplasia in 15 (30%). During a median follow-up period of 7.2 years, 18% of patients experienced recurrence. No significant difference in recurrence rates was observed between the ESD and ESD/EMR groups. ConclusionEndoscopic resection, including EMR, ESD and hybrid techniques, enables effective treatment of visible dysplastic lesions as an alternative to colectomy in patients with IBD. In this cohort, favorable short-term outcomes were demonstrated after endoscopic resection.

Comparative evaluation of a language model and human specialists in the application of European guidelines for the management of inflammatory bowel diseases and malignancies.

Society guidelines on colorectal dysplasia screening, surveillance, and endoscopic management in inflammatory bowel disease (IBD) are complex, and physician adherence to them is suboptimal. We aimed to evaluate the use of ChatGPT, a large language model, in generating accurate guideline-based recommendations for colorectal dysplasia screening, surveillance, and endoscopic management in IBD in line with European Crohn's and Colitis Organization (ECCO) guidelines. 30 clinical scenarios in the form of free text were prepared and presented to three separate sessions of ChatGPT and to eight gastroenterologists (four IBD specialists and four non-IBD gastroenterologists). Two additional IBD specialists subsequently assessed all responses provided by ChatGPT and the eight gastroenterologists, judging their accuracy according to ECCO guidelines. ChatGPT had a mean correct response rate of 87.8%. Among the eight gastroenterologists, the mean correct response rates were 85.8% for IBD experts and 89.2% for non-IBD experts. No statistically significant differences in accuracy were observed between ChatGPT and all gastroenterologists (P=0.95), or between ChatGPT and the IBD experts and non-IBD expert gastroenterologists, respectively (P=0.82). This study highlights the potential of language models in enhancing guideline adherence regarding colorectal dysplasia in IBD. Further investigation of additional resources and prospective evaluation in real-world settings are warranted.

Efficacy and safety of endoscopic submucosal dissection for colorectal dysplasia in patients with inflammatory bowel disease: a systematic review and meta-analysis.

In this meta-analysis, we studied the safety and efficacy of endoscopic submucosal dissection (ESD) for colorectal dysplasia in patients with inflammatory bowel disease (IBD). Multiple databases were searched, and studies were retrieved based on pre-specified criteria until October 2022. The outcomes assessed were resection rates, procedural complications, local recurrence, metachronous tumors, and the need for surgery after ESD in IBD. Standard meta-analysis methods were followed using the random-effects model, and I2% was used to assess heterogeneity. Twelve studies comprising 291 dysplastic lesions in 274 patients were included with a median follow-up of 25 months. The pooled en-bloc resection, R0 resection, and curative resection rates were 92.5% (95% confidence interval [CI], 87.9%-95.4%; I2=0%), 81.5% (95% CI, 72.5%-88%; I2=43%), and 48.9% (95% CI, 32.1%-65.9%; I2=87%), respectively. The local recurrence rate was 3.9% (95% CI, 2%-7.5%; I2=0%). The pooled rates of bleeding and perforation were 7.7% (95% CI, 4.5%-13%; I2=10%) and 5.3% (95% CI, 3.1%-8.9%; I2=0%), respectively. The rates of metachronous recurrence and additional surgery following ESD were 10% (95% CI, 5.2%-18.2%; I2=55%) and 13% (95% CI, 8.5%-19.3%; I2=54%), respectively. ESD is safe and effective for the resection of dysplastic lesions in IBD with an excellent pooled rate of en-bloc and R0 resection.

A238 BEST APPROACH TO SURVEILLANCE COLONOSCOPY FOR COLORECTAL CANCER IN PATIENTS WITH PRIMARY SCLEROSING CHOLANGITIS AND INFLAMMATORY BOWEL DISEASE

Abstract Background Primary sclerosing cholangitis (PSC) is a chronic, cholestatic liver disease and it has been recognized as a risk factor for hepatobiliary and colorectal carcinoma (CRC). Inflammatory bowel disease (IBD) is associated with a 6-fold increased risk of CRC as compared to the general population but with co-existing PSC, this risk rises to 30-fold and hence CRC surveillance is critical in these patients. Aims We performed a systematic review of the literature on surveillance colonoscopy for CRC in patients with PSC-IBD, with the aim of identifying the most effective approach. Methods The protocol was registered in the International Prospective Register of Systematic Reviews (PROSPERO) under ID 472215. The search was executed in the databases Medline, EMBASE, Cochrane, Web of science, Scopus and Google Scholar databases from 1947 to May 2023. Observational or randomized controlled studies were included if patients had PSC-IBD (paediatric or adult) undergoing surveillance colonoscopy. There was no restriction for language. We used a modified version of the Newcastle–Ottawa Quality Assessment Scale to assess the risk of bias. Neoplasia was defined as the presence of low-grade dysplasia, high grade dysplasia or colorectal carcinoma. Results Amongst 2900 studies identified, 7 studies met the inclusion criteria with a total number of 379 PSC-IBD patients and 1884 IBD patients (all adult). The median frequency of surveillance colonoscopy was every 0-2 years. The most common endoscopic presentation of dysplasia in PSC-IBD was a normal appearing mucosa or subtle abnormalities such as mild inflammation. Three studies performed random and targeted biopsies and only one study did quadruple random biopsy (every 10 cm of the colon). Two studies used chromoendoscopy and high-definition endoscopy whereas another two studies used white light colonoscopy. Studies varied in terms of the number of biopsies taken and timing for the frequency and initiation of surveillance. Outcomes included intensive surveillance, resection, and colectomy. Our meta-analysis of 2 studies that reported the prevalence of colorectal dysplasia in PSC-IBD patients revealed a pooled prevalence of 21% (95% CI 1.4%-28%, I2 = 0%, Pampersand:003C0.597, shown in Figure 1) Conclusions Colorectal dysplasia is prevalent in patients with PSC-IBD and is associated with worse disease outcomes. As a result, PSC-IBD patients should be screened annually from the diagnosis of PSC. However, there is variation in practice, and no clear consensus on the best approach to perform screening colonoscopy in this population. Literature comparing various approaches is very sparse. Additional high-quality studies on this subject are needed to guide practice, particularly in paediatrics where data are non-existent. Figure 1: Forest plot for meta-analysis of CRC dysplasia prevalence in PSC-IBD Funding Agencies None

P389 Comparative Evaluation of ChatGPT and Human Specialists in the Application of ECCO Guidelines for the Management of Inflammatory Bowel Diseases and Malignancies: A Proof-of-Concept Study

Abstract Background Societal guidelines on colorectal dysplasia screening, surveillance and endoscopic management in inflammatory bowel diseases (IBD) are rather complex, and physician adherence to them is suboptimal. We aimed to evaluate the use of ChatGPT, a large language model, in generating accurate guideline-based recommendations for colorectal dysplasia screening, surveillance and endoscopic management in IBD in line with European Crohn’s and Colitis Organization (ECCO) guidelines. Methods Thirty clinical scenarios in the form of free text regarding colorectal dysplasia in IBD were prepared and presented to ChatGPT and four gastroenterologists, two of them specializing in IBD and two with non-IBD specialties. Two additional IBD specialists subsequently assessed all responses provided by ChatGPT and the four gastroenterologists, judging their accuracy according to ECCO guidelines. Results ChatGPT provided accurate recommendations in 90% of cases (27/30), while among the four gastroenterologists the correct response rates were 28/30 (93%), 23/30 (77%), 26/30 (87%), and 25/30 (83%). The latter two represent the correct response rates of the IBD experts. No statistically significant differences were observed between the accuracy of ChatGPT versus all gastroenterologists (p=0.44), or between the accuracy of ChatGPT versus the IBD experts and non-IBD expert gastroenterologists (p=0.71). Conclusion This study highlights the potential of language models in enhancing guideline adherence regarding colorectal dysplasia in IBD. Further investigation of additional resources and prospective evaluation in real-world settings are warranted.

P503 Differentiation of patients with IBD at increased risk of CRC using UR-CARE: A Single Centre Experience

Abstract Background The United Registries for Clinical Assessment and Research (UR-CARE) platform aims to facilitate and improve the daily clinical care of patients with Inflammatory Bowel Disease (IBD). The possibility of updating the medical data in UR-CARE at each patient visit allows for strict follow-up and enables the doctor to draw relevant recommendations. The study is aimed at identifying registered IBD patients at increased risk of colorectal cancer (CRC) via UR-CARE. Methods Outpatients and inpatients with a confirmed IBD diagnosis, who had signed informed consent, were entered with their clinical data in UR-CARE to the centre UMHAT “Tsaritsa Yoanna-ISUL”. Only the statistical and filter opportunities of the digital platform were used. The study was conducted with our own data from our centre database. Results 274 IBD patients (120 with ulcerative colitis [UC], 144 with Crohn’s disease [CD] and 10 with IBD unclassified [IBD-U]) were entered in UR-CARE. Among all registered patients, colorectal dysplasia was entered for 19 (6.93%) persons (15 males; 14 with UC). The column for “Dysplasia” in the drop-down menu could be left empty. These 19 patients with colorectal dysplasia make up 7.98% of all 238 patients with filled in one of the three options for dysplasia. 7 (2.55%) IBD patients (5 males; 5 with UC) had primary sclerosing cholangitis, and for two of them with UC, colorectal dysplasia was entered. Among all registered IBD patients, four had undergone surgery for CRC, and one patient was operated on for familial adenomatous polyposis. UR-CARE filtered 73 patients with extensive and left-sided UC with a duration of UC ≥ 8 years who should undergo screening colonoscopy for dysplasia. Conclusion UR-CARE can quickly and effectively differentiate patients with IBD and at an increased risk of developing CRC. It enables the provision of graphic data and provides access to the files of patients at high risk of CRC, allowing for their individual follow-up.

P453 Surveillance for colorectal dysplasia and neoplasia in Latin American patients with Ulcerative Colitis

Abstract Background colorectal cancer (CRC) in patients with inflammatory bowel disease (IBD) has worse prognostic features and a higher mortality rate compared to sporadic CRC. Screening colonoscopy is therefore an important tool to consider in this population. The aim of this study is to describe the findings of endoscopic surveillance of CRC in patients with IBD using the technology available in Latin American countries. Methods Descriptive, multicentre, cross-sectional, descriptive study conducted in multiple Latin American countries in patients with ulcerative colitis (UC) more than 8 years after diagnosis and ulcerative colitis with primary sclerosing cholangitis regardless of the time of diagnosis of colitis. Surveillance colonoscopies were performed according to the availability of technology in each country. Results 78 subjects, 50% women, from 5 countries (Colombia, Costa Rica, Peru, Ecuador, and Dominican Republic), with mean age 47.9 (range 20.01-89.71; SD 151.4) years, mean age at disease diagnosis of 34.7 (range 8.52-80.9; SD 14.08) years, and mean time of disease of 12.8 (range 4.6-56.8; SD 8.9) years. 57.7% (45/78) with extensive colitis, 8.9% (7/78) with a family history of colorectal cancer. 52.6% (41/78) on biologic therapy. 24.4% (19/78) current use of Azathioprine. 9% (7/78) of corticosteroids. 70.5% (55/78) oral mesalazine. In 5.1% it was used white light, 1.3% high resolution white light, 76.9% digital chromoendoscopy and 16.7% chromoendoscopy with staining. In those with digital chromoendoscopy, NBI was used in 38.3% (28/73), 37% (27/73) LCI/BLI, and 24.6% (14/73) I-Scan. It was found pseudopolyps in 50% (39/78), and 11.5% (9/78) stenosis. 7.7% (6/78) had a history of previous dysplasia. Regarding the Paris classification modified by SCENIC consensus, 28.2% (22/78) found 0-I lesions, 16 subjects were 0-I s, and 6 subjects 0-Ip. 5 subjects had 0-II lesions, of which 4 subjects in 0-IIa, and 1 in 0-IIc. 1 subject had lesion type 0-III. 1 subject had mixed lesions (0-IIa+0-IIc), 6.4% (5/78) lesion with ulceration, 10.2% (8/78) with disruption of lesion borders, with KUDO classification, Kudo III, 5.1 (4/78) Kudo IV and 3.8% (3/78) Kudo V. Endoscopic resectability was possible in all lesions. Histological findings were: (11/78) low grade dysplasia, (1/78) high grade dysplasia and (3/78) adenocarcinoma. As for the presence of dysplasia not visible in white light in random biopsies, it was only detected in (2/78). Conclusion in this first Latin American study, endoscopic techniques with digital chromoendoscopy with targeted biopsies were preferred, most were endoscopically visible and resectable lesions suggesting that the yield of targeted biopsies is superior to random biopsies.

P536 Outcome of colorectal cancer surveillance in paediatric inflammatory bowel disease: Time for new guidelines?

Abstract Background Paediatric inflammatory bowel disease (IBD) patients have an increased risk of colorectal cancer (CRC). Current guidelines advise to conduct CRC surveillance colonoscopy eight years following IBD diagnosis, or more often in case other risk factors for CRC are present, such as previous findings of colorectal dysplasia, or a concomitant primary sclerosing cholangitis (PSC) diagnosis. However, these guidelines are based on adult data and with no regard to the patient’s age, while frequent endoscopies impose a significant burden on children. In this study, we aimed to estimate the risk of dysplasia and CRC in paediatric IBD patients before the ages of 18 and 27 years. Methods Using the Dutch Nationwide Pathology Databank (PALGA), we examined the incidence and prevalence of dysplasia and CRC in patients up to 27 years in all Dutch paediatric IBD patients diagnosed between 1991 and 2023. Additionally, we assessed the influence of PSC diagnosis on CRC risk. Results Out of the 7,873 patients with biopsy-proven paediatric IBD, 24 developed dysplasia (0.34%) and two (0.025%) developed CRC before the age of 18 years. Out of the 3,425 patients from this cohort currently aged over 26 years, eleven (0.3%) developed CRC between 17 and 27 years. Overall, 120 patients (1.5%) were diagnosed with concomitant PSC, seven (5.8%) of which developed dysplasia and two (1.6%) of which developed CRC before the age of 27 years. The median time between IBD diagnosis and CRC diagnosis was 9.5 years in this cohort. Overall, CRC incidence before the age of 27 years decreased between 1991 and 2023. Additional clinical data on IBD localisation, severity of the disease, and concomitant diagnoses could not reliably be obtained from this database. Conclusion In this retrospective study, we found low prevalence of dysplasia and CRC in paediatric IBD patients, both before the age of 18 years and before the age of 27 years. PSC prevalence was low in this cohort, since only biopsy-proven PSC was included. However, we showed that PSC significantly increased the risk of CRC in paediatric IBD patients. Based on our findings it could be proposed to initiate CRC surveillance beyond the age of 18 years by experienced adult gastroenterologists, except in case of a concomitant PSC diagnosis.

Potential carcinogenic role of Reg IV in ulcerative colitis-associated colorectal neoplasia.

Early detection of ulcerative colitis-associated neoplasia (UC-N) remains a clinical challenge. Identification of molecular biomarkers for colorectal dysplasia and cancer may be extremely beneficial in early detection and managing cancer risk in long-standing ulcerative colitis (UC) patients. The aim of this work is to investigate the role of Reg IV in comparison to P53 and KRAS in UC-associated dysplasia and colorectal cancer (CRC) in order to evaluate the potential use of Reg IV for dysplasia and cancer screening in UC patients. The study was conducted on 5 groups each 20 colonic endoscopic samples: 1) Normal colonic mucosa, 2) Active UC without dysplasia/carcinoma, 3) UC-associated dysplasia, 4) UC-associated CRC (UC-CRC), 5) Sporadic CRC. All included cases were subjected to Reg IV mRNA expression analysis by quantitative reverse transcription polymerase chain reaction, and immunostaining for Reg IV, P53 and KRAS. Reg IV mRNA expression levels were found to be significantly higher in groups 3 and 4 (mean: 3.37 and 5.70, respectively). Reg IV immunostaining was highly expressed in groups 3 and 4 (mean: 45.80 and 62.35, respectively). While P53 and KRAS immunostaining was highly expressed in group 5 (mean: 64.57 and 62.90). Furthermore, Reg IV immunoexpression had shown a negative correlation with P53 and KRAS immunoexpression in groups 4 and 5. Higher expression of Reg IV in patients with UC-dysplasia and UC-CRC versus KRAS and P53 expression in sporadic CRC, suggests a potential role of Reg IV in UC carcinogenesis pathway. This could advocate the use of Reg IV as a screening biomarker for UC-N among patients with long-standing UC as well as a promising targeted therapeutic strategy.

Management of the Rectal Stump after Subtotal Colectomy Operations for Inflammatory Bowel Disease in the Era of Immunologic Therapy: A Two-Centre Cohort Study

Introduction: Inflammatory bowel disease (IBD) often requires surgical resection, such as subtotal colectomy operations to alleviate symptoms. However, IBD also has an inherently increased risk of colorectal dysplasia and cancer. Despite the well-accepted surveillance guidelines for IBD patients with an intact colon, contemporaneous decision-making models on rectal stump surveillance is sparse. This study looks at the fate of rectal stumps in IBD patients following subtotal colectomy. Methods: This is a two-centre retrospective observational cohort study. Patients were identified from NHS Grampian and NHS Highland surgical IBD databases. Patients that had subtotal colectomy between January 01, 2010 and December 31, 2017 were included with the follow-up end date on April 1, 2021. Socio-demographics, diagnosis, medical and surgical management data were collected from electronic records. Results: Of 250 patients who had subtotal colectomy procedures, only one developed a cancer in their rectal stump (0.4%) over a median follow-up of 80 months. A higher than expected 72% of patients had ongoing symptoms from their rectal stumps. Surveillance was varied and inconsistent. However, no surveillance, flexible sigmoidoscopy, or MRI identified dysplastic or neoplastic disease. Conclusion: Based on our results, we estimate that the prevalence of rectal cancer is lower than previously reported. Surveillance strategy of rectal stump varied as no current guidelines exist and hence is an important area for future study. Given the relatively low frequency of rectal cancer in these patients, and the low level of evidence available in this field, we would propose a registry-based approach to answering this important clinical question.

77 Malignancy Incidence in the Residual Rectum of Ibd Patients After Colectomy: Systematic Review and Meta-Analysis

Abstract Aim The primary objective of this study is to estimate the incidence of rectal carcinoma in patients with an Inflammatory Bowel Disease diagnosis, who have had a total colectomy preserving the rectum. The secondary objectives are to identify the risk factors associated with malignancy occurrence and to explore the current recommendations for screening processes for these patients. Method A systematic review in 5 databases was conducted to identify studies adhering to the PICO criteria. The included studies were critically appraised, and the relevant data was extracted. Malignancy incidence was estimated from the reported information and risk stratification was analysed using RevMan. A narrative approach was undertaken for the exploration of the existing screening guidelines. Results A total of 24 studies were included. The pooled incidence of rectal carcinoma across 23 studies was calculated to be 1.3%. Subgroup analysis showed an incidence of 0.7% and 3.2% for patients with a rectal stump and ileo-rectal anastomosis respectively. Patients with a history of a colorectal carcinoma were more likely to have a subsequent diagnosis of rectal carcinoma (RR 7.2), similarly to patients with a history of colorectal dysplasia (RR 5.1). Ten studies reported frequent surveillance using endoscopy and rectal biopsies. No studies recommending screening guidelines for the target population could be identified. Conclusions The overall risk for malignancy incidence was estimated to be 1.3% which is lower than previously quoted. Due to the paucity of good quality of literature in this field, it is not possible to suggest further guidance for this cohort of patients at present.

Endoscopic Surveillance for Colorectal Cancer in Pediatric Ulcerative Colitis: A Survey Among Dutch Pediatric Gastroenterologists.

This study aimed to evaluate the current clinical practice of Dutch pediatric gastroenterologists regarding the surveillance for colorectal dysplasia and cancer in pediatric ulcerative colitis (UC), including adherence to guidelines, the initiation and interval of surveillance and applied endoscopy techniques. A clinical vignette-based survey was distributed among all 47 pediatric gastroenterologists who are registered and working in the Netherlands. Thirty-three pediatric gastroenterologists treating children with UC, completed the questionnaire (response rate 70%). Of these respondents, 23 (70%) do conduct endoscopic surveillance in their UC patients. Adherence to any of the available guidelines was reported by 82% of respondents. Twenty-four of 31 respondents (77%) indicated the need for development of a new guideline. Profound variation was witnessed concerning the initiation and interval of surveillance, and risk factors taken into consideration, such as disease extent and concomitant diagnosis of primary sclerosing cholangitis (PSC). The available national and European guidelines recommend the use of chromoendoscopy in the performance of surveillance. This technique was conducted by 8% of respondents, whereas 50% conducted conventional endoscopy with random biopsies. The heterogeneity in surveillance practices underlines the need for consistency among the guidelines, explicitly stated by 77% of the respondents. For this, future research on surveillance in pediatric UC is warranted, focusing on the risk of UC-associated colorectal cancer related to risk factors and optimal endoscopy techniques.

Frequency and Clinical Impact of Microsatellite Instability in Colorectal Dysplasia Subgroups

Frequency and Clinical Impact of Microsatellite Instability in Colorectal Dysplasia Subgroups

Long-term disease course, cost and prognosis of inflammatory bowel disease: epidemiological studies of a European and a Danish inception cohort.

Long-term disease course, cost and prognosis of inflammatory bowel disease: epidemiological studies of a European and a Danish inception cohort.

Colorectal dysplasia in chronic inflammatory bowel disease: a contemporary consensus classification and interobserver study

The clinical management of patients with dysplasia in chronic inflammatory bowel disease (IBD) is currently guided by Riddell et al.'s grading system (negative, indefinite, low grade, high grade) from 1983 which was based primarily on nuclear cytoarchitectural characteristics. Although most dysplasia in IBD resembles sporadic adenomas morphologically, other distinctive potential cancer precursors in IBD have been described over time. Recognizing the need for a updated comprehensive classification for IBD-associated dysplasia, an international working group of pathologists with extensive clinical and research experience in IBD devised a new classification system and assessed its reproducibility by having each participant assess test cases selected randomly from a repository of electronic images of potential cancer precursor lesions. The new classification system now encompasses three broad categories and nine sub-categories: 1) intestinal dysplasia (tubular/villous adenoma-like, goblet cell deficient, crypt cell, traditional serrated adenoma-like, sessile serrated lesion-like and serrated NOS), 2) gastric dysplasia (tubular/villous and serrated), and 3) mixed intestinal-gastric dysplasia. In the interobserver analysis, 67% of the diagnoses were considered definitive and achieved substantial inter-rater agreement. The key distinctions between intestinal and gastric lesions and between serrated and non-serrated lesions achieved substantial and moderate inter-rater agreement overall, respectively, however, the distinctions among certain serrated sub-categories achieved only fair agreement. Based on the Riddell grading system, definite dysplasia accounted for 86% of the collective responses (75% low grade, 11% high grade). Based on these results, this new classification of dysplasia in IBD can provide a sound foundation for future clinical and basic IBD research.

INCIDENTAL DYSPLASIA DURING TOTAL PROCTOCOLECTOMY WITH ILEOANAL POUCH: IS IT ASSOCIATED WITH WORSE OUTCOMES?

Patients with inflammatory bowel disease (IBD) are at increased risk of colorectal cancer. In cases of invisible or non-endoscopically resectable dysplasia found at colonoscopy, total proctocolectomy with ileal pouch anal anastomosis can be offered with good long-term oncological outcomes and pouch survival, however, little is known regarding cancer-related outcomes when dysplasia is found incidentally after surgery. We hypothesized incidental colorectal dysplasia is associated with worse oncologic outcomes compared to dysplasia diagnosed preoperatively.

Management of colorectal high-grade dysplasia or cancer resected by cold snare polypectomy: a multicenter exploratory study

The clinical course and surveillance strategy for patients who undergo cold snare polypectomy (CSP) for high-grade dysplasia (HGD) or cancer is unclear. We investigated the management of colorectal HGDs and cancers following CSP. This Japanese nationwide multicenter exploratory study was retrospectively conducted on patients who had undergone CSP for colorectal HGDs or cancers and follow-up colonoscopy at least once from 2014 to 2020. We investigated the detection rate of CSP scars, local recurrence rate (LRR), risk factors for local recurrence, and follow-up strategy. This study was registered with the University Hospital Medical Information Network (UMIN) Clinical Trials Registry (UMIN000043670). We included 155 patients with 156 lesions. CSP scars were identified in 22 (31.4%), 41 (54.7%), and 10 (90.9%) patients with curative, borderline, and non-curative resection, respectively. Among them, residual tumors were observed in one (4.5%), six (14.6%), and three (30.0%) cases, respectively. The total LRR was 13.7% (95% confidence interval: 6.8-23.8). R1 resection cases (either horizontal or vertical margins positive for tumors) were associated with local recurrence (p = 0.031). Salvage endoscopic and surgical resections were performed on 21 and 10 patients, respectively. Among them, the proportion of endoscopically suspected residual tumors was significantly higher (p < 0.001) in the residual tumor-positive group (100%) than in the residual tumor-negative group (28.6%). LRR after CSP for HGDs or cancers was 13.7% based on scar-identified cases. Salvage endoscopic or surgical resection should be performed according to the curability of the lesion and endoscopic findings during colonoscopic surveillance.

P362 Systematic review: Oncological outcomes of patients with Inflammatory Bowel Disease undergoing segmental colonic resections for colorectal cancer and dysplasia

Abstract Background Current international guidelines recommend that patients with inflammatory bowel disease (IBD) diagnosed with high grade dysplasia (HGD), or colorectal cancer undergo a proctocolectomy, and that proctocolectomy is considered within a shared decision-making framework with the patient in cases of low grade (LGD) or indeterminate (IND) dysplasia. However, segmental colectomy (surgical resection leaving remaining colon or rectum) is considered by some as a valid alternative, with less physiological stress, stoma avoidance and thus acceptability to patients. This systematic review aims to assess oncological and post-operative outcomes in studies reporting on segmental colectomy or proctocolectomy for patients with IBD and colonic or rectal dysplasia and cancer. Methods This systematic review was prospectively registered with PROSPERO (CRD42021292891) and carried out in line with the PRISMA guidelines. Studies published between 1990 and 2022 reporting on oncological and surgical outcomes of adult patients undergoing segmental resection and/or proctocolectomy that included at least three cases of neoplasia were included. Descriptive statistics were used in the context of significant heterogeneity. A meta-analysis was performed for outcomes with at least three results. Results The search returned 2178 results, and after screening 12 studies were included in the final analysis. A total 12,701 patients were included reporting on outcomes of 10,386 segmental resections and 2,315 proctocolectomies. The pooled incidence of missed synchronous cancers (i.e. identified in remaining colon or rectum within 6 months of surgery) in the segmental resection group was 1.4%, and dysplasia 0.5%; metachronous cancer recurrence was 1.4% (1.1% in subtotal colectomy, 11.8% in any other segmental resection), and dysplasia recurrence 5.3% (4.7% in subtotal colectomy, 7.5% in any other segmental). Average time to recurrence for metachronous cancer was 6.5 years. Recurrence of metastatic cancer was 0.2% for proctocolectomy, and 0.1% for segmental resection (OR 1.28, 95% CI 0.19 - 8.65, p =ns). Conclusion Segmental colectomy does not disadvantage against metastatic cancer recurrence. The incidence of missed synchronous lesions is low. There is increased metachronous cancer risk, however this is mitigated by subtotal colectomy. These results may help to counsel patients regarding the risks and benefits of segmental resection for IBD-related dysplasia and cancer. The risk of metachronous cancer after segmental resection reiterates the need for enhanced high quality post-operative surveillance. The paucity of data in this field is also demonstrated here by the high inter-study heterogeneity, highlighting the need for prospective studies.

INCIDENTAL DYSPLASIA DURING TOTAL PROCTOCOLECTOMY WITH ILEOANAL POUCH: IS IT ASSOCIATED WITH WORSE OUTCOMES?

Abstract BACKGROUND Patients with inflammatory bowel disease (IBD) are at increased risk of colorectal cancer. In cases of invisible or non-endoscopically resectable dysplasia found at colonoscopy, total proctocolectomy with ileal pouch anal anastomosis can be offered with good long-term oncological outcomes and pouch survival, however, little is known regarding cancer-related outcomes when dysplasia is found incidentally after surgery. We hypothesized incidental colorectal dysplasia is associated with worse oncologic outcomes compared to dysplasia diagnosed preoperatively. METHODS Using our prospectively collected pouch registry, we identified patients who had a) preoperative dysplasia or b) dysplasia found only after colectomy. Patients with cancer preoperatively or after colectomy were excluded. Included patients were divided into three groups: ONLYPRE (+preoperative biopsy, negative final pathology), PREFINAL (+preoperative biopsy and final pathology), and ONLYFINAL (negative preoperative biopsy, +final pathology. Long-term pouch survival in the three groups was assessed with survival analysis. RESULTS In total, 517 patients were included: ONLYPRE = 125 (24%), PREFINAL = 254 (49%), ONLYFINAL = 137 (26%). Overall, the median age at IPAA was 46 (IQR 36 - 62) and 33% were female. The preoperative diagnosis was ulcerative colitis in 91% cases. No demographic differences were observed between the groups. In patients with a positive preoperative biopsy, the concordance between preoperative biopsy and final pathology was 49% (Figure 1a). After a median follow-up of 12 years (IQR 3 – 21), there were no differences in overall, disease-free or pouch survival between groups (Figure 1b, c, d). Cancer/dysplasia developed in 11 patients: 3 (2%) in the ONLYPRE, 5 (2%) in the PREPOST, and 3 (2%) in the ONLYPOST group (Table 1). Oncologically, one required redo pouch (ONLYPRE group), while 4 required pouch excision: 1 (1%) In ONLYPRE, 1 (0.5%) in the PREPOST, and 2 (2%) in the ONLYPOST group (p = 0.24). Only one cancer-related death occurred in the entire cohort (ONLYPRE group). Disease-free survival at 10 years was 98% for ONLYPRE, 98% for PREPOST, and 98% for ONLYPOST (p = 0.968). Pouch survival at 10 years was 96% for ONLYPRE, 99% for PREPOST, and 97% for ONLYPOST (p = 0.236). CONCLUSION An ileoanal pouch in the setting of IBD-associated dysplasia, regardless of when it is diagnosed, confers exceptionally good long-term outcomes. The incidental finding of dysplasia during proctocolectomy does not seem to be associated with worsened outcomes compared to preoperatively diagnosed dysplasia.

Prognostic models for colorectal cancer incidence and mortality in patients with inflammatory bowel disease

Objectives This is a protocol for a Cochrane Review (prognosis). The objectives are as follows: Primary objectives The primary objectives are to identify, describe, and appraise all prognostic models developed to predict colorectal cancer incidence or mortality in patients with IBD, at any time point after the clinical diagnosis of IBD, and if possible meta‐analyse their predictive performances. Investigation of sources of heterogeneity between studies Sources of heterogeneity to be investigated comprise differences in the definition of colorectal dysplasia, colorectal cancer and IBD, the type of IBD investigated, study design, time point for prognostication after the clinical diagnosis of IBD, time horizon for outcome measurements, length of follow‐up, and statistical analysis applied (Debray 2017).