Retrospective Comparison of the Efficacy of Therapeutic Agents in Metastatic Soft-Tissue Sarcomas

Abstract

OBJECTIVE There are few agents used in soft-tissue sarcoma treatment. We compared the efficacy of therapies, aiming to identify the best therapy sequence, and reveal the factors affecting the risk of progression or death. METHODS Fifty-five patients were included in the study. Data such as age, gender, tumor primary site, histological type, tumor grade, the Ki67 percentage score, treatments, radiotherapy, and metastasectomy history, the dates of diagnosis, metastasis, progression, and death were retrospectively evaluated. Progression-free survival (PFS) and overall survival (OS) for therapies, and the risk factors for the progression or death were analyzed. RESULTS In the first-line, gemcitabine-docetaxel provided longer PFS than the doxorubicin-ifosfamide combination (7.4 months vs. 4.8 months, p=0.035), although this did not result in OS difference. In the secondline, the efficacy of trabectedin and pazopanib were similar, whereas trabectedin showed less activity in liposarcomas. In the third-line and beyond, trabectedin, pazopanib and eribulin showed similar PFS and OS. The only factor that affected the risk of death was metastasectomy (HR for death: 0.35, 95% CI: 0.18–0.66, p=0.001). CONCLUSION We found that agents used in soft-tissue sarcoma have similar efficacy, which is not affected by the previous therapies. However, it should be noted that soft-tissue sarcomas include many histological types, and to choose the optimal drug, the histological type must be one of the major factors considered. Furthermore, all patients should be evaluated for possible metastasectomy, which came out as the only factor reducing the risk of death in our study