PRIMARY RADIATION-THERAPY FOR ENDOMETRIAL CARCINOMA - A CASE-CONTROLLED STUDY

Purpose: Primary radiation therapy is generally considered inferior to a surgical approach for patients with endometrial carcinoma and is reserved for patients with a high operative risk. These patients are usually elderly, have multiple medical problems and frequently die of intercurrent disease. To evaluate the efficacy of primary radiation therapy a case controlled analysis comparing corrected survival of patients treated with primary radiation to patients treated with surgical therapy with or without radiation therapy was performed. Methods and Materials: Sixty-four patients treated with primary radiation therapy were retrospectively studied. A Kaplan-Meier product limit survival analysis was used to estimate survival among patients treated with primary radiation therapy. A case control study matched by clinical stage, tumor grade, and time of diagnosis was performed. The Mantel-Cox statistic was used to evaluated the equality of the survival curves. Results: Primary radiation therapy was used to treat 9.0% of the patients with endometrial carcinoma during the study period. Cardiovascular disease, diabetes, age greater than 80 and morbid obesity were the most common indications. Ninety percent of patients had either Stage I or II disease. Forty-eight of the 64 patients (75%) completed treatment which included both teletherapy and brachytherapy. Ten patients received brachytherapy only. Twelve complications, both acute and chronic, occurred in eleven patients (17%). Intercurrent disease accounted for 13 of the 36 (36%) of the deaths. Clinical stage of disease and histologic grade of the tumor were significant predictors of survival, p = 0.0001 and p = 0.013, respectively. The case controlled study of Stage I and II patients treated by primary radiation therapy matched to surgically treated controls showed no statistical difference in survival. Dilatation and curettage after the completion of radiation therapy was predictive of local control, p 0.003. Conclusion: Although surgery followed by tailored radiation therapy has become widely accepted therapy for Stage I and II endometrial carcinoma, even in patients who are a poor operative risk, the survival with primary radiation therapy is not statistically different.