Assessing the Accuracy of the Association of Coloproctology of Great Britain and Ireland's Risk Assessment Tool for Polyp Cancer Management: A Retrospective Study.

Objective This study aims to evaluate the accuracy of the Association of Coloproctology of Great Britain and Ireland's (ACPGBI) 2013 risk assessment tool in predicting residual disease and lymph node involvement in patients diagnosed with malignant polyps. Other factors such as polyp size, site, and excision type were also evaluated to determine if they increase the risk of residual disease.  Materials and methods A retrospective analysis of prospectively collected data was conducted in a UK district general hospital from April 2020 to March 2024. Patients with a histological diagnosis of malignant colorectal polyp(s) were included and followed up with endoscopy and CT at the one-year follow-up. Multivariable analysis was used to evaluate the additional risk factors. Results Malignant polyps were identified in 125 patients. Ninety-five patients had adenocarcinoma-containing polyps. No patient with a risk of less than 20% had residual malignancy. Of the patients with an ACPGBI risk score of 20% or more (n = 65), 34 underwent surgical intervention. Seven were found to have residual disease, and four had positive lymph nodes in the resected specimen. Total residual disease risk for patients with an ACPGBI risk score of four or more was 18%. Polyp size was the only additional factor found to be a significant independent risk factor for determining the risk of residual disease following endoscopic polyp removal (OR 1.1, Wald X2 15.4, p = 0.007). Conclusion The ACPGBI risk tool accurately reflects the risk of residual disease for those within the highest risk category (score of four or more). Polyp size was found to carry a statistically significant risk of predicting residual disease.