Karna, Rahul

Abstract Introduction Underwater endoscopic mucosal resection (uEMR) technique has gained popularity for removal of large non-pedunculated colorectal polyps (LNPCPs) due to high en-bloc resection rates and lower recurrence rates. However, there is no information regarding outcomes of uEMR for giant colorectal polyps. Therefore, we aimed to evaluate the outcomes of uEMR for giant colorectal polyps across multiple centers in North America. Methods We conducted a multicenter retrospective study of adults with giant colorectal polyps undergoing uEMR between January 2019 and November 2025. Giant colorectal polyps were defined as LNPCPs ≥40 mm. Primary outcomes were technical success and rate of recurrent adenoma. Secondary outcomes were severe adverse events (SAEs) and predictors of technical success, recurrence, and SAEs. Results A total of 137 polyps, with mean polyp size 47.6 mm were included. Majority of the lesions were located in right colon (61%, n = 83) with the most common histopathology being high-grade dysplasia (HGD) (31.4%, n = 43). Technical success was achieved in 90.5% (n = 124) with en-bloc resection rate of 11.7% (n = 16). Polyp fibrosis (OR: 0.08) and HGD (OR: 0.15) were independent predictors of inability to achieve technical success. Of 92 (67.1%) patients with follow-up, recurrent polyp was present in 8.7% (n = 8). SAEs were noted in 9.5%, consisting of delayed bleeding (9.5%, n = 13), while no delayed perforation or post polypectomy syndrome was noted. Discussion Our study demonstrates that uEMR is technically feasible for the removal of giant colorectal polyps with an acceptable safety profile and recurrence rate.

Abstract Background: Placebo response is crucial in interpreting treatment efficacy in ulcerative colitis (UC) trials. While it has been broadly studied, it remains underexplored in trials involving the growing number of biologics and small molecules for ulcerative colitis. Methods: We systematically searched PubMed, Embase, Scopus, Web of Science, and Cochrane CENTRAL from inception to November 13, 2024. Eligible studies were induction-phase RCTs, including adult patients with moderate-to-severe UC who received a biologic and a small-molecule against a placebo. Primary outcomes were pooled clinical and endoscopic response and remission rates. Safety outcomes included adverse events (AEs), serious adverse events (SAEs), and withdrawal rates. Random-effect models were used for meta-analysis. Meta-regression identified predictors of placebo outcomes. Results: 26 induction RCTs with 3,937 placebo-treated patients were included. IL inhibitor trials had the highest placebo clinical response (36%) and endoscopic remission (21%), while JAK inhibitors had the lowest (21% and 2%). Overall placebo rates were 34% for clinical response, 8% for clinical remission, 19% for endoscopic response, and 11% for endoscopic remission. Adverse events occurred in 54%, SAEs in 8%, and withdrawals in 18%. Younger age and longer follow-up were linked to higher placebo responses; recent trials showed reduced endoscopic effects. Conclusion: These findings highlight the need to account for placebo variability in trial design and interpretation, particularly as biologic and small-molecule therapies continue to expand in UC treatment.

e14591 Background: Combined immune checkpoint inhibitors (ICPI) have revolutionized treatment of solid tumors. Their use can lead to treatment-related adverse events (TRAEs) resulting in hospital admissions, treatment discontinuation and increased morbidity. We aim to evaluate gastrointestinal (GI) TRAEs of different combination ICPI. Methods: A comprehensive search of multiple databases from inception to October 2021 was performed. Phase 2 and 3 trials assessing safety and efficacy of combined ICPI in solid tumors were included. Trials reporting concurrent use of chemotherapy, immunosuppressants, targeted therapy, or sequential ICPI therapy were excluded. Primary outcome was pooled luminal, hepatic and pancreatic TRAEs. A meta-analysis of proportions was done for outcomes using a random-effects model. I2 % was used to assess heterogeneity. Results: Out of 3696 citations screened, 53 trials reporting TRAEs in 6186 patients were included. Data from 41 study arms of 35 trials in nivolumab plus ipilimumab (N+I), 15 study arms of 15 trials in durvalumab plus tremelimumab (D+T), 4 study arms of 3 trials in pembrolizumab plus ipilimumab (P+I). The most common indications for combined ICPI were melanoma (26.4%) and lung cancer (24.5%). Pooled GI TRAE rates from the D+T, P+I and two different dosing combinations of N+I are shown in the table. Conclusions: Our study provides pooled data of TRAEs from different combination ICPI use in solid tumors and demonstrates high incidence of all grades and ≥ 3 GI TRAEs. Combined ICPI related TRAEs should be recognized early, as it may require treatment discontinuation. Further studies are required to assess overall impact of TRAEs on treatment course and outcomes.[Table: see text]