3745 - Impact of Molecular Classification on Adjuvant Treatment Decisions in Endometrial Cancer: A Comparative Analysis
Presenter(s)
B. H. Zobec Logar1,2, M. Dorman1, and N. Štraus1; 1Faculty of Medicine, University of Ljubljana, Ljubljana, Slovenia, 2Division of Radiation Oncology, Institute of Oncology Ljubljana, Ljubljana, Slovenia
Purpose/Objective(s): Endometrial cancer is one of the most common gynecological malignancies. While surgical treatment remains the cornerstone of management, adjuvant therapy plays a crucial role in reducing the risk of recurrence in selected patients. Traditionally, decisions regarding adjuvant treatment have been based on clinicopathological factors and FIGO staging. However, these criteria alone have shown limitations in accurately predicting prognosis and guiding individualized treatment. The aim of this study was to evaluate the impact of molecular classification on postoperative adjuvant treatment decisions in patients with endometrial cancer.
Materials/Methods: This retrospective study included patients with endometrial cancer treated with primary surgery and adjuvant therapy at the Institute of Oncology Ljubljana between 2021and 2024. Clinicopathological and molecular characteristics, risk stratification, and adjuvant treatment modalities were analyzed. Risk group allocation before and after incorporation of molecular classification was compared. Descriptive statistics were used to evaluate each variables.
Results: A total of 412 patients were included in the final analysis. Mean age was 64.5 ± 10.7 years. Stage distribution: I 22.1%, II 46.8%, III 27.7%, IV 3.4%. Molecular subtypes: POLEmut 1.2%, MMRd 33.3%, p53abn 13.3%, NSMP 55.8%; 3.2% had multiple classifiers. Risk stratification changed in 10.9% (n=45): 4.4% to low risk, 3.9% to intermediate, 2.2% to high-intermediate, and 0.2% to high risk due to a p53abn molecular profile. Overall, 30 patients (7.3%) received adjuvant treatment tailored according to molecular reclassification. Most changes resulted in de-escalation of therapy, reflecting the favorable prognosis associated with certain molecular subtypes.
Conclusion: Molecular classification alters risk grouping in approximately 11% of patients and influences adjuvant treatment in 7%. Although the proportion is modest, integration of molecular profiling refines prognostic assessment and supports more individualized postoperative management. Continued evaluation in larger cohorts and with long-term follow-up is warranted to further define the clinical benefits of molecularly integrated risk stratification.