LAUSR

Abstract Rationale: Trabectedin is an antitumor drug considered to be effective for liposarcoma, leiomyosarcoma, and translocation-related sarcoma. Concerning liposarcoma subtypes, evidence of the efficacy of trabectedin for dedifferentiated liposarcoma (DDLPS) is poor, whereas it is known to have high efficacy against myxoid liposarcoma. Moreover, there are few reports of long-term trabectedin treatment of cases of DDLPS. Here, we present a case of advanced metastatic DDLPS that achieved long-term disease control by trabectedin treatment. Patient concerns: A 68-year-old man presented with a mass in his back. Magnetic resonance imaging showed a tumorous mass in his back which exhibited low intensity on T1-weighted and high intensity on T2-weighted images. Diagnosis: The mass was diagnosed as DDLPS by open biopsy. Interventions: The patient underwent gemcitabine+docetaxel combination therapy followed by pazopanib and eribulin; all these therapies failed to halt disease progression. Subsequently, we changed the regimen to trabectedin as fourth-line therapy. Outcome: The patient achieved stable disease for approximately 18 months during 11 cycles of trabectedin therapy. Lessons: Trabectedin should be considered as a treatment option for DDLPS even in cases of numerous failed prior chemotherapy regimens.