Systemic Therapy for Soft Tissue Sarcoma: Proposals for the Optimal Use of Pazopanib, Trabectedin, and Eribulin

Soft tissue sarcoma (STS) is a rare tumor with more than 50 histologic subtypes. Although treatment outcomes for patients with STS have improved greatly over the past few decades owing to the adoption of a multidisciplinary approach, patients with advanced disease have a poor prognosis. The development of anticancer drugs has been directed toward improving overall survival (OS). Doxorubicin monotherapy is currently the only standard option for the first-line treatment of STS. However, there is no standard therapy for second-line and later treatment at present. Since 2012, three anticancer drugs-pazopanib, trabectedin, and eribulin-have been approved in Japan for the second-line or later treatment of patients with advanced STS of any histologic subtype. However, the chemosensitivity of STS to each of these drugs varies by histologic subtype and their safety profiles differ; thus, histologic subtype and patient characteristics must be considered when determining optimal treatment. In this article, we review data from clinical studies related to the efficacy of all three drugs, including their effect on OS, and propose optimal treatment strategies for advanced STS by histologic subtype. In addition, with regard to the safety profiles, we highlight the key issues to be considered when selecting patients for treatment with pazopanib, trabectedin, or eribulin and ensuring their appropriate use, based on our combined clinical experience as specialists in the treatment of patients with STS. The proposed treatment strategies as well as treatment precautions based on clinical experience would benefit patients by maximizing the therapeutic effects and enhancing the proper use of these drugs.