The role of adjuvant radiotherapy in stage I endometrial cancer: A single-institution outcome

ObjectivePostoperative radiotherapy for early endometrial cancer has been investigated in several randomized trials. These trials demonstrate that it reduces loco-regional recurrence, but has no impact on overall survival. The aims of this study were to better understand the role of adjuvant radiotherapy and determine predictors for loco-regional recurrence or development of distant metastasis.Materials and methodsA retrospective medical records review was performed on patients with surgical stage I endometrial cancer treated at Taipei Veterans General Hospital between 2006 and 2013. Multivariable analysis was conducted using Cox regression for prognostic predictors.ResultsA total of 337 patients were identified. The estimated five-year overall survival and loco-regional recurrence-free survival were 96.3% and 97.9% in the non-radiotherapy group, and 91.6% and 97.1% in the radiotherapy group (p = 0.06 overall survival, p = 0.956 loco-regional recurrence-free survival). Multivariable analysis revealed that elevated preoperative serum Cancer Antigen 125 (CA-125) level (hazard ratio (HR) = 2.54), age older than 60 years old (HR = 3.34), and depth of myometrial invasion > 50% (HR = 3.37) were significant factors in overall survival. Elevated preoperative CA-125 level (HR = 5.37), age older than 60 years (HR = 6.57), positive lymphovascular space invasion (HR = 50.20), and adjuvant radiotherapy (HR = 0.05) were independent predictors of loco-regional recurrence-free survival. For distant metastasis, deep myometrial invasion was a significant risk factor.ConclusionsPostoperative radiotherapy delivery is an independent predictor for loco-regional recurrence-free survival but has no impact on overall survival in this population. Preoperative CA-125 level is a risk factor for loco-regional recurrence, and deep myometrial invasion was correlated with distant metastasis.