RESULTS OF POSTOPERATIVE RADIOTHERAPY IN THE TREATMENT OF SARCOMA OF THE CORPUS UTERI

BACKGROUND. The role of radiotherapy in the treatment of uterine sarco ma still is not clear. Data from the literature advocating adjuvant ra diotherapy most often are based on very small patient groups, whereas larger epidemiologic studies, which appear to show no benefit for the additional radiotherapy, lack information regarding clinical data infl uencing the choice for adjuvant irradiation. METHODS. During 1981-1992 , 72 patients were referred for postoperative radiotherapy. Histologic diagnoses were leiomyosarcoma (LMS) in 30 patients, endometrial strom al sarcoma (ESS) in 11 patients, mixed mullerian tumors (MMT) in 28 pa tients, and other sarcoma types in 3 patients. The 1988 International Federation of Gynecology and Obstetrics classification for endometrial carcinoma was applied retrospectively. Forty patients presented with Stage I disease, 9 with Stage II, 17 with Stage III, and 6 with Stage IV. External beam therapy was given with a cobalt-60 unit using a rota tion technique with 2 separate arcs in daily fractions of 2 gray (Gy), up to a total dose of 56 Gy to the pelvis. Brachytherapy was given to the vaginal vault either with 2 radium applications (median: 1600 mil ligram-hours to the applicator surface) or, in the majority of cases, with 3 fractions of high dose rate afterloading applications (iridium- 192, 10-Curie source) with 7 Gy each to an isodose 7.5 mm from the app licator surface. RESULTS. The 5-year actuarial overall survival, disea se specific survival, and local control rates for 72 patients were 52. 3%, 58.5%, and 77.9%, respectively; in Stage I patients they were 74.8 %, 84.6%, and 94.4%, respectively; in Stage II patients they were 53.3 %, 53.3%, and 88.9%, respectively; in Stage III patients they were 15. 7%, 17.9%, and 55.5%, respectively; and in Stage IV patients they were 0%, 0%, and 0%, respectively. For LMS, the 5-year actuarial overall s urvival, disease specific survival, and local control rates were 49.4% , 52.0%, and 76.0%, respectively; for ESS they were 81.8%, 81.8%, and 90.9%, respectively; and for MMT they were 42.3%, 54.9%, and 72.4%, re spectively. CONCLUSIONS. These data suggest that adjuvant radiotherapy is an effective treatment for uterine sarcoma with regard to disease specific survival in patients with early stage disease and increases l ocal control, even in patients with advanced stage disease. Cancer 199 8;83:1972-9. (C) 1998 American Cancer Society.