Impact of adjuvant treatments and risk factors on survival in 2023 FIGO stage IIB endometrial cancer patients: Turkish Gynecologic Oncology Group Study

Objective The aim of this study was to investigate the impact of adjuvant treatments, factors influencing recurrence, and survival data in patients with 2023 International Federation of Gynecology and Obstetrics (FIGO) stage IIB endometrial cancer. Methods A retrospective analysis was conducted on patients with endometrial cancer who underwent surgery between 2005 and 2022 at seven different centers in Turkey. Demographic, clinicopathological, and survival data were collected and analyzed. Results Among 7323 patients, 565 (7.7%) were classified as 2023 FIGO stage IIB based on pathological results. Of 565 patients, 214 were followed without receiving adjuvant treatment, while 335 (95.4%) received adjuvant radiotherapy, and 16 (4.6%) received radiotherapy and chemotherapy. The locoregional recurrence rate was higher in patients with a tumor size >4 cm (p=0.038) and myometrial invasion >50% (p=0.045). In patients with distant metastasis, the recurrence rate was lower in those with myometrial invasion <50% compared with myometrial invasion ≥50% (p=0.031). The impact of adjuvant treatment on endometrial cancer patients revealed no significant differences for both disease free survival (p=0.85) and overall survival (p=0.54). Subgroup analyses showed that in patients with deep myometrial invasion, adjuvant treatment was associated with a significant increase in overall survival (p=0.044), but there was no effect on disease-free survival (p=0.12). Conclusions Patients with stage IIB endometrial cancer with myometrial invasion ≥50% were more likely to have locoregional and distant metastases. Adjuvant radiotherapy or chemoradiotherapy did not demonstrate an overall survival benefit in these patients.