Pazopanib as a second line treatment for uterine and ovarian carcinosarcoma: a single institutional study

Uterine carcinosarcoma (UCS) is a relatively rare tumor in gynecologic malignancy that comprises less than 5% of uterine cancers, but it often shows an aggressive phenotype that has contributed to 30% of uterine cancer deaths [1]. Ovarian carcinosarcoma (OCS) is a very rare ovarian tumor that accounts for only 1% of ovarian cancer, and is composed of both malignant epithelial and mesenchymal elements, as well as UCS [1,2]. Prognosis of UCS and OCS is poor because up to 2/3 of patients present with advanced stage [2,3]. Currently, prognostic factors of carcinosarcoma (CS) are not well defined, but published reports have suggested pathological features and age as prognostic factors [4,5,6]. Previously, gynecological CS had been considered and treated as a sarcoma subtype [7]. However, CS is now recognized as a metaplastic carcinoma with the sarcoma component resulting from dedifferentiation of the carcinoma component [8], and therefore it is recommended that CS is treated similar to high-risk endometrial or ovarian carcinoma [9]. While combination chemotherapy of ifosfamide and paclitaxel is currently considered as a standard chemotherapy for UCS [10], an alternative combination is carboplatin and paclitaxel. The efficacy of combination carboplatin and paclitaxel has been reported in several phase II trials, and this combination appears to be better tolerated [11,12]. Based on these results, the combination of carboplatin plus paclitaxel is often used as a standard first line treatment for UCS or OCS, but second line treatment options are limited.