Chemotherapy for Uterine Carcinosarcoma with Carboplatin, Ifosfamide and Mesna

Uterine carcinosarcomas (UCSs) are highly aggressive, rare, biphasic tumors composed of epithelial and mesenchymal elements. Surgery remains the mainstay of treatment in early-stage disease. Adjuvant pelvic radiotherapy improves locoregional control without proven overall survival (OS) benefit. Although adjuvant ifosfamide-based combination chemotherapy with cisplatin or paclitaxel has shown superiority to radiotherapy or single-agent chemotherapy in randomized controlled trials, there is no consensus on a standard regimen due to toxicities. The aim of this retrospective study was to assess the efficacy and toxicity of a novel combination chemotherapy using carboplatin, ifosfamide and mesna (CIM) and compare with other regimens for patients with UCSs in both the adjuvant and palliative setting.

Between 1997 and 2010, 60 patients with UCS, 70% of whom with international federation of gynecology and obstetrics (FIGO) stage III/IV disease, were treated with adjuvant or palliative chemotherapy. Two groups were identified: Group1 (n=22) included patients receiving CIM chemotherapy; and group 2 (n=38) receiving other regimens (carboplatin/paclitaxel/cisplatin/doxorubicin/epirubicin).

After a median follow-up of 60 months, disease in seven patients in group 1 (CIM) and 20 patients in group 2 had progressed/relapsed. Out of these, six patients in group 1 and 13 patients in group 2 had died. The progression-free survival (PFS) and OS for patients treated with adjuvant or palliative CIM was 35 months [95% confidence interval (CI) =0.26-0.43] and 47 months (95% CI=0.38-0.56; log-rank, p=0.001) respectively, whereas for group 2 patients treated with other regimens, PFS was 27.48 months (95% CI=0.20-0.33) and OS was 30 months (95% CI=0.21-0.38; log-rank, p=0.001). While none of the patients in group 1 experienced neurotoxicity or other grade 3 or 4 toxicities, 3/38 patients in group 2 experienced grade 3 neutropenia, 4/38 had peripheral sensory neuropathy, 6/38 patients had treatment deferred due to toxicities or allergic reaction to paclitaxel.

In the phase III randomized controlled trial combination of ifosfamide and taxanes has shown PFS and OS benefit when compared to single-agent ifosfamide at the expense of significant toxicities. Results from our study show that the combination of CIM is an effective and safe alternative regimen for patients with advanced UCSs. In addition to improved OS and PFS, the main advantage of this regimen over taxane-based regimens includes minimal neuropathy, less use of steroids, and low risk of allergic reaction. CIM should be considered in future prospective studies looking at the treatment of UCS.