Is there a survival benefit to adjuvant radiotherapy in high-risk surgical stage I endometrial cancer?

Objective. The aim of this study was to examine the effects of therapeutic modalities on survival of stage I endometrial cancer and also to evaluate the surgical morbidity and the prognostic importance of surgicopathological variables. Methods. A hundred and ninety-six stage I endometrial cancer patients treated at Hacettepe University Hospital between 1982 and 1997 were included. After initial diagnosis all patients underwent surgical procedures including peritoneal cytology, infracolic omentectomy, total abdominal hysterectomy, bilateral salphingoopherectomy, and complete pelvic-paraaortic lymphadenectomy. The mean age at initial diagnosis was 56 years (SD = 9.9 years) and the patients were followed 3-18 years (median, 8 years). All patients had endometrioid carcinoma. Stage IC and/or grade 3 tumors were considered high-risk factors and by this definition 147 (75%) patients were low risk and 49 (25%) patients were high risk. Forty-nine percent of high-risk patients received adjuvant radiotherapy compared with 3.5% of patients in the low-risk group. Results. The 10-year disease-free and overall survival rates of the entire group were 97 and 98%, respectively. Ten-year overall survival rate for the low-risk group was 100% compared with 94% for patients with high-risk features (P = 0.002). The 10-year disease-free survival rate in the high-risk group was 96% for 24 patients who received adjuvant radiotherapy versus 92% for 25 patients who did not receive adjuvant therapy (P = 0.53). Only high grade was a significant predictor of poor survival (P = 0.0004). Overall surgical morbidity rate was 8.1% without mortality related to surgery. Conclusions. Surgical staging achieved excellent survival for stage I endometrial cancer patients without incurring untoward morbidity and mortality. No survival advantage of adjuvant radiotherapy was detected even for high-risk patients, so we suggest the use of radiotherapy may be reserved for relapse. (C) 2002 Elsevier Science (USA).