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

Abstract

Objective: Postoperative 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 methods: A 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. Results: A 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. Conclusions: Postoperative 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. Keywords: Endometrial neoplasms, Radiotherapy, Adjuvant