Effect of time interval between surgery and the initiation of adjuvant therapy on the oncologic outcomes of early‐stage endometrial cancer

Abstract

AbstractObjectiveTo identify the impact of time interval between surgery and initial adjuvant radiotherapy on oncologic outcomes in early‐stage endometrial cancer.MethodsThis retrospective cohort study included patients with stage I/II endometrial cancer who underwent surgical staging and adjuvant therapy at Songklanagarind Hospital from January 1, 2007, to December 31, 2017. Patients were categorized into two groups: TI <6 weeks and TI ≥6 weeks. The effects of TI and clinicopathological factors on recurrence‐free survival (RFS) and overall survival (OS) were analyzed using Cox proportional‐hazards regression.ResultsIn total, 177 patients were enrolled, with 52% receiving adjuvant radiotherapy at <6 weeks (overall median TI 5.7 weeks). The recurrence and death rates were 13% and 10.2%, respectively. The median follow‐up time was 46.6 months. The overall 3‐year RFS and OS rates were 88.2% and 85.2%, respectively. The TI significantly affected the 3‐year RFS (94.4% vs 81.2%; P = 0.008) and 3‐year OS (95.5% vs 83.2%; P = 0.012) in patients with TI <6 and ≥6 weeks, respectively. In multivariate analysis, the depth of myometrial invasion (MI), presence of lymphovascular space invasion, and TI were independent prognostic factors for both RFS and OS. Delaying the TI (≥6 weeks) was significantly associated with a worse RFS (hazard ratio [HR] 3.70; 95% confidence interval [CI]: 1.34–10.22; P = 0.012) and an inferior OS (HR 3.80; 95% CI: 1.23–11.69; P = 0.02).ConclusionA delay in the TI between surgery and the initiation of adjuvant radiotherapy of ≥6 weeks negatively affected the oncologic outcomes in early‐stage endometrial cancer.