Results of postoperative radiotherapy in the treatment of sarcoma of the corpus uteri.

Abstract

The role of radiotherapy in the treatment of uterine sarcoma still is not clear. Data from the literature advocating adjuvant radiotherapy 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 influencing the choice for adjuvant irradiation. During 1981-1992, 72 patients were referred for postoperative radiotherapy. Histologic diagnoses were leiomyosarcoma (LMS) in 30 patients, endometrial stromal sarcoma (ESS) in 11 patients, mixed müllerian tumors (MMT) in 28 patients, 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 rotation 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 milligram-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 applicator surface. The 5-year actuarial overall survival, disease 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 survival, 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%, respectively. 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 local control, even in patients with advanced stage disease.