Interplay Between p53 and Wnt/β-Catenin Signaling in Colorectal Cancer: Associations with Mismatch Repair Status, Tumor Microenvironment, and Clinicopathological Outcomes

The interplay between TP53 alterations and Wnt/β-catenin signaling in colorectal cancer (CRC) remains unclear regarding mismatch repair (MMR) status, tumor budding (TB), poorly differentiated cluster (PDC), and prognosis. We analyzed 146 resected CRC cases, quantifying p53, Wnt3, and β-CTN indices and assessing MMR by PMS2 and MSH6 immunohistochemistry. p53 overexpression was associated with younger patients, left-sided tumors, nodal metastasis, and advanced stage, whereas wild-type tumors showed more mucinous differentiation. Deficient MMR was enriched among wild-type p53 cases. Principal component analysis identified distinct axes defined by p53, Wnt3, and β-CTN. Despite comparable Wnt3 levels, nuclear β-CTN accumulation was enhanced in tumors with aberrant (overexpression or null) p53 tumors, with increased TB and PDC indices. Low nuclear β-CTN independently predicted recurrence in stage I-III disease and worse overall survival in proficient MMR tumors (HR 3.07 and 2.52; <i>p</i> = 0.03 for both). A composite score integrating p53 binary status (aberrant vs. wild) with Wnt3 and whole β-CTN indices predicted survival beyond stage; each 1-point increase conferred a 2.56- and 1.77-fold higher risk of cancer-specific and overall mortality (<i>p</i> = 0.004 and 0.04). These findings suggest that p53 dysfunction is associated with alterations in Wnt/β-CTN signaling and that integrating signaling markers with staging may improve prognostic assessment in colorectal cancer.