Optimum risk stratification in an early stage of endometrial cancer (EC) combines molecular and clinicopathological features. The purpose of the study was to determine the prognostic value of molecular classification and traditional pathological factors in a sample group of patients with stage I EC according to the FIGO 2023 criteria, to achieve a more personalized approach to patient care and treatment. The immunohistochemistry for p53 and mismatch repair (MMR) proteins, and DNA sequencing for POLE exonuclease domain and clinicopathological parameters, including disease disease-free survival (DFS) and overall survival (OS) in 139 patients, were analyzed. It has been shown that the independent recurrence risk factors are stage IC (p < 0.001), aggressive histological types EC (p < 0.001), and the presence of p53abn protein immunoexpression (p = 0.009). Stage IC (p = 0.018), aggressive histological types EC (p = 0.025) and the presence of p53abn protein immunoexpression (p = 0.010) were all significantly associated with lower 5-year OS rates. Our research studies confirm that the molecular category corresponds to a different prognosis in clinical stage I EC according to the new 2023 FIGO classification, with POLEmut cases presenting the best outcomes and p53abn cases showing the worst outcomes. Beyond the previous routine clinicopathological assessment, the new EC staging system represents an important step toward improving our ability to stratify IC stage EC risk.
Keywords: 2023 FIGO endometrial cancer staging; molecular classification; prognostic factors.