The impact of surgery–radiotherapy interval on prognosis in high-risk endometrial cancer patients: A single-center retrospective analysis

This study aims to investigate the impact of surgery-radiotherapy (S-RT) interval on the prognosis of high-risk endometrial cancer (EC) patients receiving postoperative adjuvant therapy. It evaluates the effect of different interval times on disease-free survival (DFS) to provide clinical treatment recommendations. This retrospective study included 150 high-risk EC patients who underwent surgery at our hospital between February 2021 and February 2023. Patients were categorized into 3 groups based on the S-RT interval: short interval (1-4 weeks), medium interval (5-8 weeks), and long interval (>8 weeks). Baseline data, treatment characteristics, and follow-up data were collected and analyzed. Primary outcomes included DFS and the effect of S-RT interval on DFS. Kaplan-Meier method was used for survival analysis, and multivariate Cox regression model - adjusting for key confounding factors such as age, Fédération Internationale de Gynécologie et d'Obstétrique stage, pathological type, deep myometrial invasion, lymphovascular space invasion (LVSI), and lymph node metastasis - was applied to evaluate independent prognostic factors. The 2-year DFS rate for the short interval group was 55%, significantly higher than the medium interval group (49%) and long interval group (24%), with statistically significant differences between the groups (P < .001). Cox regression analysis indicated that the S-RT interval is an independent prognostic factor for DFS, with the long interval (>8 weeks) group showing a significantly increased risk of recurrence compared to the short interval group (HR = 1.9, 95% CI: 1.4-2.5, P < .001). Pathological features such as deep myometrial invasion, LVSI positivity, and lymph node metastasis were also independent prognostic factors. The timing of postoperative radiotherapy initiation significantly affects prognosis in high-risk EC patients, even after adjusting for key clinical and pathological variables. Delayed radiotherapy (>8 weeks) markedly increases recurrence risk. These findings suggest that shortening the S-RT interval may improve DFS. However, the results need to be validated in larger sample sizes and multi-center prospective studies before generalization.