Postoperative Radiotherapy Alone Versus Chemoradiotherapy in Stage I-II Endometrial Carcinoma: An Investigational and Propensity Score Matching Analysis

The purpose of this study was to compare the results of postoperative adjuvant radiotherapy (RT) and concurrent chemoradiotherapy (CRT) in stage I-II endometrial carcinoma. We analyzed a total of 64 patients with surgically staged I-II endometrial carcinoma who were treated with postoperative adjuvant RT or concurrent CRT between March 1999 and July 2013. Thirty-two patients who received postoperative RT alone were matched with those who received postoperative CRT (n=32) in accordance to age, stage, and tumor histology. Overall survival and relapse-free survival, as well as toxicity of the RT and CRT arms were evaluated and compared. The 5-year overall survival rate was 90.0% for the RT arm and 91.6% for the CRT arm. There was no significant difference in overall survival between the two treatment arms (p=0.798). The 5-year relapse-free survival rate was 87.2% in the RT arm and 88.0% in the CRT arm. Again, no significant difference in relapse-free survival was seen between the two arms (p=0.913). In a multivariate analysis, tumor histology was an independent prognostic factor for relapse-free survival (hazard ratio, 3.67; 95% of CI, 2.34 to 7.65; p=0.045). Acute grade 3 or 4 hematologic toxicities in the CRT arm were significantly higher than in the RT alone arm (6.2% vs. 31.2%, p=0.010). Adjuvant pelvic concurrent chemoradioherapy did not show superior results in overall survival and relapse-free survival compared to RT alone in stage I-II endometrial carcinoma.