Prevalence of Endoscopically Curable Low-Risk Cancer Among Large (≥20 mm) Nonpedunculated Polyps in the Right Colon

Abstract

Background and aimsEndoscopic submucosal dissection (ESD) is increasingly promoted for the treatment of all large non-pedunculated colorectal polyps (LNPCP), to cure potential low-risk cancers (superficial submucosal invasion without additional high-risk histopathological features). The effect of a universal en bloc strategy on oncological outcomes for the treatment of LNPCP in the right colon is unknown. We evaluated this in a large Western population. MethodsA prospective cohort of patients referred for endoscopic resection (ER) of LNPCP was analysed. Patients found to have cancer after ER and those referred directly to surgery were included. The primary outcome was to determine the proportion of right colon LNPCP with low-risk cancer. ResultsOver 180 months until June 2023, 3294 sporadic right colon LNPCP in 2956 patients were referred for ER at 7 sites (median size 30mm [IQR 15]). 63 (2.1%) patients were referred directly to surgery and cancer was proven in 56 (88.9%). 2851/2956 (96.4%) LNPCP underwent ER (median size 35mm [IQR 20]) of which 75 (2.6%) were cancers. The overall prevalence of cancer in the right colon was 4.4% (131/2956). Detailed histopathological analysis was possible in 115/131 (88%) cancers (71 after ER, 44 direct to surgery). After excluding missing histopathological data, 23/2940 (0.78%) sporadic right colon LNPCP were low-risk cancers. ConclusionsThe proportion of right colon LNPCP referred for ER containing low-risk cancer amenable to endoscopic cure was <1%, in a large, multicentre Western cohort. A universal ESD strategy for the management of right colon LNPCP is unlikely to yield improved patient outcomes given the minimal impact on oncological outcomes. Clinical TrialAustralian Colonic Endoscopic Resection (ACE) cohort: NCT01368289 (https://classic.clinicaltrials.gov/ct2/show/NCT01368289); NCT02000141 (https://classic.clinicaltrials.gov/ct2/show/NCT02000141)