Radiation therapy in the treatment of endometrial stromal sarcoma.

OBJECTIVE: The efficacy of radiation therapy in the treatment of endometrial stromal sarcoma (ESS) is still not clear. We report our results over an 18-year period in comparison to data from literature concerning adjuvant radiation therapy and other treatment modalities. PATIENTS AND METHODS: During 1981-1998, 21 patients with ESS were treated at General Hospital Vienna. The age of the patients ranged between 44-76 years (median: 65 yr). The 1989 FIGO classification for endometrial carcinoma was used in this study retrospectively. Eleven patients presented in Stage I, 1 in Stage II and 5 in Stage III. Four patients had Stage IV tumors or recurrences. The majority of patients (66.7%) had a Grade 3 tumor. Seventeen patients were treated in a curative intent. Fifteen patients were referred for postoperative radiotherapy after hysterectomy. Thirteen of them received a combined radiotherapy. Two patients were referred for primary radiotherapy. They received a combined radiotherapy. Four patients were referred for radiotherapy with a palliative intent. Twenty patients received external beam therapy (EBT) in daily fractions of 1.6-2.0 Gy up to a total dose of 27-57 Gy to the pelvis. Seventeen patients received brachytherapy.
RESULTS: Follow-up was 8 to 170 months (mean: 70.3 months, median: 64 months). Eleven patients are still alive, 10 without tumor and 1 with tumor. Ten patients are dead, 6 due to ESS, 1 due to breast cancer, and 3 due to intercurrent diseases. After adjuvant radiotherapy, 3 patients had tumor recurrences. All had distant metastases, and 1 had local failure additionally. Two patients with primary treatment died due to intercurrent disease without tumor. The overall actuarial survival and the disease-specific survival rates were 63.4% and 80.9% after 5 years and 52.8% and 80.9% after 10 years. The overall local control rate was 93.8% after 5 years. Four patients treated with a palliative intent showed partial response. Three patients died rapidly due to tumor. One patient with a Grade 1 tumor is still alive 12 months after treatment.
CONCLUSION: In our experience, surgery and adjuvant radiation therapy are most effective treatments for patients with ESS due to the excellent local control in all stages and the good disease-specific survival in early stages.