[Pazopanib for three patients with recurrence of retroperitoneal liposarcoma : initial clinical experience]

Pazopanib, a novel tyrosine kinase inhibitor, is an effective therapeutic agent for patients with advanced soft tissue sarcoma. Here we report three patients with recurrent retroperitoneal liposarcoma who were treated with pazopanib. Case 1: A 54-year-old male received three courses of combined chemotherapy consisting of doxorubicin and ifosfamide for recurrent left retroperitoneal dedifferentiated liposarcoma and liver metastasis following tumor excision. Because of the lack of response to chemotherapy, 400 mg/day of pazopanib was subsequently administered for two weeks. The patient died 3 weeks after the initiation of pazopznib therapy. Case 2: A 78-year-old male with right retroperitoneal dedifferentiated liposarcoma underwent irradiation for a recurrent tumor 16 months after the initial tumor excision. Pazopanib (600 mg/day) was partially effective for 2 months. Pazopanib was administered for 7 months, but the patient died 8 months after the initiation of pazopanib therapy. Case 3 : An 80-year-old male with locally recurrent right retroperitoneal myxoid liposacroma was treated with 600 mg/day of pazopanib from 5 months after tumor excision. He remains alive and has had stable disease for 17 months to date. In conclusion, pazopanib may be effective in a subset of patients with recurrent retroperitoneal liposarcoma.