Prognostic parameters in endometrial stromal sarcoma: a clinicopathologic study in 31 patients

The aim of this study was to evaluate the behavior of endometrial stromal sarcomas (ESS) in relation to their clinical and pathologic features and to identify possible prognostic factors.

Thirty-one patients with histologically proven ESS were included in the analysis. Endometrial stromal sarcoma is characterized by proliferations composed of cells with endometrial stromal cell differentiation. A breakpoint of 10 mitoses per 10 high-power fields was used in the statistical analysis to distinguish between low-grade and high-grade endometrial stromal sarcoma and to evaluate the prognostic value of mitotic count in patients with ESS.

The median follow-up time was 72 months (range 34-110). The median overall survival of the 31 patients was 127 months, resulting in a 5-year overall survival rate of 62%. Adjuvant therapy was administered to 25 patients; among those, 20 patients received postoperative radiotherapy and 5 patients received chemotherapy. Ten of the irradiated patients and 3 patients undergoing chemotherapy developed disease recurrence. Concerning the response rate to adjuvant chemotherapy, 1 patient showed a complete response, 1 patient a partial response, 1 patient stable disease, and 2 patients progressive disease. Altogether, 14 patients developed recurrent disease with a median disease-free survival of 11 months (range 5-60). Twelve patients died of the disease. A univariate model revealed that early tumor stage (P < 0.0007), low myometrial invasion (P < 0.008), and low mitotic count (P < 0.005) were associated with a lengthened overall survival in patients with endometrial stromal sarcoma. Age and adjuvant therapy did not influence overall survival of patients with ESS.

Early tumor stage, low myometrial invasion, and low mitotic count are associated with a lengthened overall survival in patients with ESS.