Abstract
(1) Background: Colorectal cancer (CRC) is the third most common cancer in terms of incidence and mortality. Approximately 90% of all colorectal cancer cases are adenocarcinomas, originating from epithelial cells of the colorectal mucosa. Upregulated gene 4 (URG4) is an oncogene involved in cancer development. The aim of the study was to assess the immunohistochemical expression of URG4 protein expression in Polish patients with colon adenocarcinoma who were not treated with any therapy before radical surgery. (2) Methods: The study used colon tissue samples taken from people with a confirmed diagnosis of colorectal adenocarcinoma after a thorough histopathological examination. The associations between the immunohistochemical expression of URG4 and clinical parameters were analyzed by the Chi2 test or Chi2Yatesa test. The study conducted an analysis of the correlation between the expression of URG4 and the five-year survival rate of patients through the application of the Kaplan-Meier analysis and the log-rank statistical test. The intracellular localization of URG4 was identified through the utilization of transmission electron microscopy (TEM) methodology. (3) Results: In univariate Cox regression analyses, immuno-histochemical expression of URG4, grade of histological differentiation, depth of invasion, angioinvasion, PCNA expression, stage of disease and lymph node involvement were found to be significant prognostic factors. Within our patient cohort, it was observed that the degree of tumour differentiation and URG4 expression were found to be distinct prognostic factors in regard to the 5-year survival rates of those with colon adenocarcinoma. (4) Conclusions: High immunohistochemical expression of URG4 correlates with poor prognosis in patients with colon adenocarcinoma.