Colon to Rectum
Gut. 2022;71(4):705–15
Multicenter derivation and validation of a colitis-associated colorectal cancer risk prediction web tool
Objective: Patients with ulcerative colitis (UC) diagnosed with low-grade dysplasia (LGD) have increased risk of developing advanced neoplasia (AN: high-grade dysplasia or colorectal cancer). The authors aimed to develop and validate a predictor of AN risk in patients with UC with LGD and create a visual web tool to effectively communicate the risk.
Design: In their retrospective multicenter validated cohort study, adult patients with UC with an index diagnosis of LGD, identified from 4 UK centers between 2001 and 2019, were followed until progression to AN. In the discovery cohort (n = 246), a multivariate risk prediction model was derived from clinico-pathological features using Cox regression. Validation used data from 3 external centers (n = 198). The validated model was embedded in a web tool to calculate patient-specific risk.
Results: Four clinico-pathological variables were significantly associated with AN progression in the discovery cohort: endoscopically visible LGD > 1 cm (hazard ratio [HR] = 2.7; 95% confidence interval [CI]: 1.2–5.9), unresectable or incomplete endoscopic resection (HR = 3.4; 95% CI: 1.6–7.4), moderate/severe histological inflammation within 5 years of LGD diagnosis (HR = 3.1; 95% CI: 1.5–6.7) and multifocality (HR = 2.9; 95% CI: 1.3–6.2). In the validation cohort, this 4-variable model accurately predicted future AN cases with overall calibration Observed/Expected = 1.01 (95% CI: 0.64–1.52), and achieved 100% specificity for the lowest risk group over 13 years of available follow-up.
Conclusion: Multicohort validation confirms that patients with large, unresected, multifocal low-grade dysplasia and recent moderate/severe inflammation are at highest risk of developing advanced neoplasia. Personalized risk prediction provided via the Ulcerative Colitis-Cancer Risk Estimator (www.uc-care.uk) can support treatment decision-making.