Clinicopathologic prognostic factors and the role of adenomyosis in endometrial cancer: A 25-year single-center experience

OBJECTIVE: The aim of this study was to characterize recurrence patterns, identify clinicopathologic prognostic factors associated with overall survival and disease-free survival, and determine the independent prognostic significance of adenomyosis in surgically treated endometrial carcinoma. METHODS: This retrospective single-center cohort included 868 patients who underwent primary surgical treatment for histopathologically confirmed endometrial carcinoma. Clinicopathologic characteristics, recurrence patterns, treatment modalities, and survival outcomes were analysed. Overall survival (OS) and disease-free survival (DFS) were estimated using the Kaplan-Meier method. Multivariable Cox regression models included age at diagnosis, FIGO stage, histologic type, and adenomyosis. Additional endometrioid-only subgroup and surgery-period sensitivity analyses were performed. RESULTS: During follow-up, recurrence occurred in 211 patients (24.3%). Recurrence was significantly more frequent in non-endometrioid tumors and increased progressively with advancing FIGO stage and tumor grade (all p < 0.001). In multivariable analysis, increasing age, advanced FIGO stage, and non-endometrioid histology were independently associated with poorer OS. Age and FIGO stage also independently predicted DFS. Adenomyosis was associated with lower unadjusted recurrence rates; however, after adjustment, it was not independently associated with OS and showed only a borderline association with DFS. Similar recurrence patterns were observed in the endometrioid-only subgroup, and surgery-period sensitivity analysis demonstrated consistent prognostic associations across different treatment eras. CONCLUSION: FIGO stage, age, and histologic type remain the major determinants of survival in endometrial carcinoma. While adenomyosis was associated with more favorable unadjusted outcomes, its independent prognostic value appears limited after accounting for established clinicopathologic factors. These findings support the continued importance of classical risk factors and highlight the need for future studies integrating molecular classification to better define the prognostic role of adenomyosis.