Prognostic factors in undifferentiated uterine sarcoma: a subanalysis of the SARCUT study.

Purpose: The aim of this study was to analyze the prognostic factors related to the recurrence rate and overall survival of patients with undifferentiated uterine sarcoma.

Methods: An international multicenter study involving 43 international centers, the SARCUT study, collected 966 uterine sarcoma cases; among them 39 cases corresponded to undifferentiated uterine sarcoma and where included in the present subanalysis. The risk factors related to the oncological outcomes where analyzed.

Results: The median age of the patients was 63 (range 14-85) years. Seventeen (43.5%) patients presented FIGO stage I. The 5-year overall survival (OS) was 15.3% and 12-months disease-free survival (DFS) 41%. FIGO stage I was significantly associated with a better prognosis. In addition, patients who received adjuvant radiotherapy showed significant longer disease-free survival compared to those without adjuvant radiotherapy (20.5 vs. 4.0 months, respectively; p = 0.04) and longer overall survival (34.7 vs. 18.2 months, respectively; p = 0.05). Chemotherapy administration was associated with shorter DFS (HR 4.41, 95% CI 1.35-14.43, p = 0.014). Persistent disease after primary treatment (HR = 6.86, 95% CI 1.51-31.09, p = 0.012) and FIGO stage IV (HR 4.12, 95%CI 1.37-12.44, p = 0.011) showed significant worse prognosis for OS.

Conclusion: FIGO stage seems to be the most important prognostic factor in patients with undifferentiated uterine sarcoma. Adjuvant radiotherapy seems to be significantly associated also to a better disease-free and overall survival. On the contrary, the role of chemotherapy administration remains unclear since was associated to a shorted DFS.