ASSOCIATION OF CLINICOPATHOLOGIC CHARACTERISTICS WITH MISMATCH REPAIR PROTEINS AND P53 IMMUNOHISTOCHEMISTRY FINDINGS IN ENDOMETRIOID ENDOMETRIAL CARCINOMA

<strong>Objective:</strong> This study aimed to evaluate the relationship between traditional prognostic clinicopathological features and the status of immunohistochemically assessed mismatch repair (MMR) pro= teins and p53 expression in endometrioid endometrial carcinoma (EEC). <strong>Material and Methods: </strong>A total of 142 EEC patients who underwent hysterectomy and lymph node resection between 2018 and 2024 were included. Immunohistochemical analysis was performed for MLH1, MSH2, MSH6, PMS2, and p53. <strong>Results:</strong> Our study showed that 66.2% of cases were MMR=profi= cient and 33.8% were MMR=deficient (dMMR). dMMR cases were significantly associated with higher International Federation of Gynecology and Obstetric (FIGO) Grade 3 tumours (33.3% vs. 10.6%) and cervical stromal invasion (39.6% vs. 23.4%). However, no signif= icant association was found between dMMR and other parameters such as tumour size or lymphovascular invasion. For p53, 11.3% of cases showed mutation=type staining, whereas 88.7% showed the wild=type. p53 mutation=type staining demonstrated significant associations with multiple aggressive clinicopathological features, such as age, FIGO grade, tumour size, myometrial invasion depth, lymphovascular invasion, and cervical stromal invasion. No case exhibited both p53 mutation=type staining and loss of MMR pro= teins.&nbsp; <strong>Conclusion: </strong>MMR status and p53 expression in EECs are distinctly associated with key clinicopathological features, such as tumour FIGO grade and cervical stromal invasion. The association of the p53 mutation type with a broader range of aggressive factors underscores the importance of molecular classification in under= standing EEC heterogeneity for prognostic evaluation and treat= ment strategies.&nbsp;