Introduction: Carcinosarcomas (malignant mixed Mullerian tumor) of the female genital tract are rare tumors associated with poor outcome. The objective of this study was to identify site-specific differences by comparing carcinosarcomas originating in the uterus and the ovaries.

Methods: Data on patients with uterine and ovarian carcinosarcomas were extracted from the Surveillance, Epidemiology, and End Results database between 1988 and 2005. Kaplan-Meier log rank and Cox proportional hazards models were used for survival analysis and for identification of possible predictors for survival.

Results: The identified cohort included 3683 women of whom 2759 (75%) have uterine carcinosarcoma and 924 (25%) have ovarian carcinosarcomas. The patients with uterine carcinosarcoma were older than the patients with ovarian carcinosarcoma (median age, 67 vs 65 years; P < 0.001). The women with uterine carcinosarcoma compared with those with ovarian carcinosarcoma were more often African American (17.3% vs 6%; P < 0.001) and presented more often with localized disease (47% vs 10.8%; P < 0.001). Uterine carcinosarcoma compared with ovarian carcinosarcoma differed significantly with regard to the performance of lymphadenectomy (62.6% vs 41.2%; P < 0.001) and the administration of radiotherapy (38.2% vs 4.8%; P < 0.001). When controlled for the extent of disease spread, uterine carcinosarcoma had a more aggressive clinical course and shorter survival compared with ovarian carcinosarcoma. Although age (P < 0.001), race (P = 0.01), stage (P < 0.001), lymphadenectomy (P < 0.001), and radiation (P < 0.001) were all significant prognostic factors in uterine carcinosarcoma, only age (P < 0.001), stage (P < 0.001), and lymphadenectomy (P < 0.001) were significant predictors in ovarian carcinosarcoma.

Conclusion: Although uterine carcinosarcoma presents at an earlier stage than ovarian carcinosarcoma, it has a worse prognosis compared with ovarian carcinosarcoma, with a similar extent of disease spread. Improved survival observed in lymphadenectomy group lends support to its routine performance in patients with uterine and ovarian carcinosarcomas.