Adjuvant radiotherapy and survival outcomes in early-stage endometrial cancer: A multi-institutional analysis of 608 women

The role of post-operative radiotherapy (RT) in women with early-stage, low to intermediate risk cancer of the uterine corpus remains controversial. The primary objective of this analysis was to evaluate the survival outcomes of women with early-stage endometrial cancer treated with surgery alone or surgery followed by RT. Data from two institutions were collected from 1990 to 2003. The 608 eligible women had FIGO stage IA to IIA endometrial cancer and underwent primary surgery ± RT. Univariate and multivariate analyses of pertinent variables were performed for the end points of disease-free survival (DFS) and overall survival (OS). The median age for all women was 64 years. RT was delivered to 133 women (22%). Unfavorable histologic grade ( P < 0.0001) and stage ( P < 0.0001) were significantly more prevalent in the adjuvant RT group. At a median follow-up of 5.2 years, 26 pelvic (11 vaginal) and 16 distant failures occurred along with 110 deaths (with no significant differences between women undergoing surgery alone or followed by RT). Adjuvant RT, younger age, and lower stage predicted for improved DFS and OS on multivariate analysis. Stratified analysis revealed that adjuvant RT conferred a survival benefit in women with stage IC or IIA disease. Adjuvant RT was associated with improved disease-free and overall survival in women with higher risk disease. Despite significantly worse disease characteristics among women in the adjuvant RT group, the analyzed end points were equivalent among the two groups. These findings suggest that adjuvant radiotherapy has a significant benefit in reducing mortality and disease progression in early-stage carcinoma of the uterine corpus.