Association of Wnt Signalling With Metachronous Colonic Polyp Risk

Edwards, J. et al. (2023) Association of Wnt Signalling With Metachronous Colonic Polyp Risk. 2023 ASCO Gastrointestinal Cancers Symposium, San Francisco, CA, USA, 19-21 Jan 2023. p. 232. (doi: 10.1200/JCO.2023.41.4_suppl.232)

Abstract

Background: Following colorectal polypectomy, 20-50% of patients develop metachronous polyps, and a proportion have increased colorectal cancer (CRC) risk. However, there are currently no molecular biomarkers for predicting metachronous polyp risk. Constitutive activation of the Wnt signalling cascade is a hallmark of polyp development and carcinogenesis, therefore biomarkers from this pathway were investigated for association with detection of metachronous polyps. Methods: A retrospective study was performed on a tissue microarray (TMA) of left sided colonic polyps from 279 patients undergoing screening polypectomy (May’09-Dec’16) followed by surveillance colonoscopy (up to 6 years). Mutational analysis was performed using the GPOL cancer plus panel, protein expression by Immunohistochemistry and RNA-sequencing by TempO-Seq (BioClavis). Log rank statistics determined associations with time to detection of metachronous polyp. Index polyp number, histology and size were compared to metachronous lesion outcome using χ2/ANOVA and multivariate polynomial regression identified independent predictors of advanced future lesions. Results: APC (91%), KRAS (30%) and SOX9 (23%) were the most frequently mutated genes and APC and SOX9 are both implicated in Wnt signalling. Mutations in APC and co-mutations in SOX9 with ARID1 were associated with a shorter time to detection of metachronous polyps. Neither variant classification nor location of mutations were associated with metachronous polyp detection. Luminal epithelial cells with high expression of E-Cadherin or SOX9 were significantly associated with earlier detection of metachronous polyps or CRC (HR 2.3, 95%CI 1.6-3.3: p<0.001 and: HR 2.0, 95%CI 1.3-3.0; p=0.001 respectively). By χ2/ANOVA analysis, E-Cadherin and SOX9 expression was associated with detection of metachronous polyp (p>0.001, p=0.037 respectively). On multivariate regression, number of polyps (HR 1.2, 95%CI 1.1-1.3; p<0.001), and E-Cadherin expression (HR 2.1, 95%CI 1.5-3; p<0.001), independently predicted metachronous lesions. Gene set enrichment analysis (GSEA) was used to explore differential biology between high and low E-Cadherin or SOX9 expression. For E-Cadherin, all seven immune-annotated MSigDB hallmarks had negative enrichment, however Wnt--catenin signaling was positively enriched (NES=1.50, p-adj<0.1). The top signature enriched for SOX9 was ‘NFB signaling via TNF (NES=1.70, p-adj<0.001). The LGR5 stemness signature was enriched in both high E-Cadherin (NES=1.97 p-adj<0.0001) and high SOX9 (NES=1.48, p-adj<0.0001) groups. Conclusions: Wnt signalling-associated protein expression within index polyp tissue is valuable for predicting metachronous polyp risk. In addition, expression of E-Cadherin and SOX9 in colonic polyps are linked to immune and stemness signatures, suggesting immune and stemness biology may be an underlying driver of metachronous polyp development.

• Item Type: Conference or Workshop Item
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Al-Badran, Ms Sara
• Authors: Edwards, J., Al-Badran, S. S.F., Hillson, L., Ammar, A., Hayman, H. L., Johnstone, M. S., Hay, J., Jawny, J., Maka, N., Andersen, D., Dunne, P. D., Roxburgh, C. S.D., Lynch, G., and McSorley, S. T.
• College/School: College of Medical Veterinary and Life Sciences > School of Cancer Sciences
• ISSN: 0732-183X
• Published Online: 24 January 2023