Prognoses and prognostic factors of carcinosarcoma, endometrial stromal sarcoma and uterine leiomyosarcoma: a comparison with uterine endometrial adenocarcinoma.

Aims: The aims of this study were to evaluate the factors affecting prognosis in patients with uterine sarcomas and to demonstrate that carcinosarcoma bears a similarity to high-grade endometrial carcinoma in terms of its prognosis and clinicopathological parameters.

Methods: In June 2004, 17 Japanese institutions received questionnaires regarding uterine sarcomas. Study patients had uterine sarcomas initially treated at each institution between January 1990 and May 2004. Survival analyses and comparisons were performed by univariate methods. Patient data of 921 cases of endometrial adenocarcinoma were also analyzed and compared to the data with the uterine sarcomas.

Results: One hundred twenty-one patients with uterine sarcomas were identified who met study eligibility criteria. In uterine sarcomas, carcinosarcoma had a worse prognosis than other sarcomas, but the difference was not significant (p = 0.302). In carcinosarcoma, significant differences were observed with age (p = 0.0388), stage (p < 0.01) and surgical procedure (with or without pelvic lymphadenectomy, p = 0.0316). In carcinosarcoma and G3 adenocarcinoma, no significant difference was identified with regard to overall survival in univariate (p = 0.191) and multivariate (p = 0.168) analyses.

Conclusion: Our results demonstrate that the clinical behavior of carcinosarcoma strongly resembles that of G3 endometrial adenocarcinoma, setting it apart from other 'pure' uterine sarcomas.