Efficacy of first-line doxorubicin and ifosfamide in myxoid liposarcoma

We retrospectively analyzed the records of 37 histologically confirmed MLS patients who were treated at the University of Texas MD Anderson Cancer Center from January 2000 to December 2009 with doxorubicin 75-90 mg/m2 over 72 hours combined with ifosfamide 10 gm/m2 in the first-line setting. Response was assessed using RECIST and Choi criteria. The Kaplan-Meier method and log-rank test was used to estimate clinical outcomes.The median follow-up period was 50.1 months. The overall response rates were 43.2% using RECIST and 86.5% using the Choi criteria. The 5-year disease-free survival rate was 90% for patients with resectable tumors. Median time to progression and overall survival time for the advanced-disease group were 23 and 31.1 months, respectively.Our study demonstrates that doxorubicin-ifosfamide combination therapy has a role in the treatment of MLS. The Choi criteria may be more sensitive in evaluating response to chemotherapy in MLS.Liposarcoma is the name given to a group of soft tissue sarcomas (STSs) with adipocytic differentiation. As a group, the liposarcomas are the second most common STS in adults. Approximately half of these tumors are further sub-classified as myxoid/round cell liposarcomas (MLSs) based on a multinodular gelatinous appearance and a unique chromosome rearrangement, t(12;16)(q13;p11), involving the DDIT3 and FUS genes, respectively. This chromosome rearrangement or a rare variant in which FUS is substituted by EWSR1 (22q12) is found in virtually all MLS cases and supports the diagnosis [1]. MLS exhibits distinct clinical features, such as a propensity to develop in the lower extremity, particularly the medial thigh or the popliteal area, and only very rarely in the retroperitoneum as a primary site [2]. Furthermore, compared with other STSs, it has a strong predisposition to metastasize to nonpulmonary sites such as the intraperitoneum, the retroperitoneum, or the paraspinal fat [2-4]. Staging and grading of these tumors are no diff