Introduction/Background The risk of recurrence in endometrial cancer patients varies between three and 40%, depending on factors such as tumor stage, histological and molecular subtype, treatment pattern, and partly unknown risk factors. Therefore, holistic characterization of recurrent endometrial cancer is urgently needed. We sought to characterize the first recurrence of endometrial carcinoma in a real-world setting.

Methodology A retrospective analysis of 250 patients, treated for the first recurrence of endometrial cancer between 2005 and 2022 at 4 German and 1 Austrian university hospitals, was conducted. A comprehensive data collection instrument was built in the REDCap database.

Results At diagnosis, 126 (48.8 %) patients presented with FIGO stage I disease, 34 (13.2%) with stage II, 72 (27.9%) with stage III, and 26 (10.1%) with stage IV. 151 (70.9%) patients had L0 status, while 62 (29.1%) patients had L1 status. At recurrence, 53 (22.6%) patients presented with vaginal bleeding, while 106 (45.3%) had unspecific symptoms. The rate of local recurrence was 48.5%, while distant metastases were found in 68.3% of cases. Regarding the pattern of treatment at recurrence: 51.8% of patients received chemotherapy. 37.4% underwent surgery and 34.6% were treated with radiotherapy. Seventy-one (30.7%) patients developed a further recurrence. Based on the analysis of patients' records, one hundred twenty-three (49.7%) patients died.

Conclusion This is the first retrospective study, characterizing the first recurrence of endometrial carcinoma in a multicenter cohort of 250 patients. The majority of patients experiencing a recurrence of endometrial cancer are treatable. Nevertheless, in cases of recurrence, the carcinoma itself is a frequent cause of death. The acquired knowledge might inform our understanding of late outcomes and guide treatment decisions to minimize therapy-associated toxicity while achieving favorable oncologic outcomes.

Disclosures All authors declare that they have no conflicts of interest.