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 re served for patients with a high operative risk. These patients are usu ally elderly, have multiple medical problems and frequently die of int ercurrent disease. To evaluate the efficacy of primary radiation thera py a case controlled analysis comparing corrected survival of patients treated with primary radiation to patients treated with surgical ther apy with or without radiation therapy was performed. Methods and Mater ials: Sixty-four patients treated with primary radiation therapy were retrospectively studied. A Kaplan-Meier product limit survival analysi s was used to estimate survival among patients treated with primary ra diation 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: Pr imary radiation therapy was used to treat 9.0% of the patients with en dometrial carcinoma during the study period. Cardiovascular disease, d iabetes, age greater than 80 and morbid obesity were the most common i ndications. Ninety percent of patients had either Stage I or II diseas e. Forty-eight of the 64 patients (75%) completed treatment which incl uded both teletherapy and brachytherapy. Ten patients received brachyt herapy only. Twelve complications, both acute and chronic, occurred in eleven patients (17%). Intercurrent disease accounted for 13 of the 3 6 (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 pa tients treated by primary radiation therapy matched to surgically trea ted 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 t ailored radiation therapy has become widely accepted therapy for Stage I and II endometrial carcinoma, even in patients who are a poor opera tive risk, the survival with primary radiation therapy is not statisti cally different.