ENDOMETRIAL STROMAL SARCOMA - ANALYSIS OF TREATMENT FAILURES AND SURVIVAL

The objective of this retrospective multicenter study was to assess th e rates, times, and sites of recurrences of 26 patients with low-grade endometrial stromal sarcomas (ESS) (<10 mitoses per 10 high-power fie lds (HPF) and 40 patients with high-grade ESS (greater than or equal t o 10 mitoses/10 HPF). Surgery was the initial therapy for all patients . Postoperative treatment was given without well-defined protocols. Th e median follow-up of survivors was 92 months (range, 4-167). Low-grad e ESS: Of the 20 patients with disease confined to the uterus, 5 (25.0 %) developed pelvic recurrence after a median of 36 months (range, 4-1 08). Of the 6 patients with disease outside the uterus, only one recur red in the pelvis after 93 months. High-grade ESS: Of the 20 patients with disease confined to the uterus, 11 (55.0%) developed recurrent di sease after a median of 5 months (range, 2-76). The relapse occurred i n the pelvis in 3 patients, in upper abdomen in 3, in upper abdomen an d extraabdominal sites in 1, and in the pelvis and upper abdomen or ex traabdominal sites in 4. Of the 12 patients with extrauterine disease confined to the pelvis, 9 (75.0%) developed recurrent disease after a median of 12 months (range, 1-49). The relapse occurred in the pelvis in 3 patients, in extraabdominal sites in 3, and in the pelvis and upp er abdomen or extraabdominal sites in 3. Of the 8 patients with extrau terine disease outside the pelvis, 7 died of disease and 1 is currentl y alive with progressive disease after 24 months. The disease-free sur vival was significantly better for low-grade than that for high-grade ESS (P = 0.0001). By log-rank test the disease-free survival of high-g rade ESS patients was related to stage (P = 0.0466) and mitotic count (P = 0.0014), but not to age. Cox model showed that mitotic count was the only independent prognostic variable for high-grade ESS (P = 0.006 ). In conclusion, low-grade and high-grade ESS have a completely diffe rent biological aggressiveness and clinical behavior. (C) 1996 Academi c Press, Inc.