Purpose: The aim of this study was to determine the prognostic factors influencing overall, disease-free and local recurrence-free survival in patients treated postoperatively with adjuvant radiotherapy for endometrial carcinoma.
Methods: The records of 440 patients with endometrial carcinoma treated by postoperative radiotherapy between January 1985 and June 1997 were reviewed retrospectively. All patients received postoperative external radiotherapy with 1.8-2.0 Gy daily fractions up to 36-68 Gy (median 54 Gy). Intracavitary brachytherapy was applied to 61.8% of the cases. Survival analysis was performed using the Kaplan-Meier method. The log-rank test was used for univariate analysis and the Cox regression model for multivariate analysis.
Results: Median age of the patients was 57 (range: 35-83). Histologically 80.2% were adenocarcinoma, 5.7% adenosquamous carcinoma, 5.2% clear-cell carcinoma and 4.3% serous papillary carcinoma. The distribution by stages were: 62.2% Stage I, 20.0% Stage II, 14.9% Stage III, 2.8% Stage IV. Median follow-up time was 53 months (7-173 months). Total failure rate was 15.2% with 2.7% of patients having only local failure, 2.0% local and distant failure and 10.5% distant failure only. Five-year overall, disease-free and local recurrence-free survival rates were 81.6%, 80.7% and 94.6%, respectively. According to univariate analysis prognostic factors influencing disease-free survival were histologic type (p=0.0067), histologic grade (p=0.0015), stage (p<0.0001), myometrial invasion (p<0.0001), peritoneal cytology (p=0.0013) and cervical involvement (p=0.0106) while the prognostic factors affecting local recurrence-free survival were stage (p=0.0277), myometrial invasion (p=0.0054), peritoneal cytology (p=0.0427). According to multivariate analysis prognostic factors influencing disease-free survival were histologic type (p=0.0194), myometrial invasion (p=0.0021), and histologic grade (p=0.0303) while the only prognostic factor influencing local recurrence-free survival was myometrial invasion (p=0.0241).
Conclusion: Radiotherapy is a highly effective adjuvant treatment providing an excellent locoregional control rate and it should be continued for patients with unfavorable prognostic factors.