Response rates of pazopanib therapy in metastatic soft tissue sarcoma using real-world data

The present study was a retrospective single-center study. A total of 81 patients diagnosed with metastatic soft tissue sarcoma were included who received pazopanib therapy. Clinical data, including age at diagnosis, histological subtype, treatments received before pazopanib, number of metastatic sites at the time of initiation of treatment, progression-free survival and overall survival time under pazopanib treatment, side effects and response evaluation in follow-up imaging after initiation of pazopanib therapy, were recorded. The 81 patients had 11 different histological subtypes. The synovial sarcoma, leiomyosarcoma and pleomorphic sarcoma groups included 51 patients in total. The median overall survival time in the entire study cohort was 46 months, and the median progression-free survival time was 5 months. The clinical response rate was 46.3%. Patients with hemangioendothelioma and alveolar soft part sarcoma exhibited an improved response to treatment compared with that of patients with other subtypes. Line of therapy and tumor grade were not significantly associated with progression-free survival or clinical response. It was concluded that, regardless of subtype, patients with a low tumor grade and a small number of metastatic sites exhibited an improved response; although the difference in response for patients with a low tumor grade was not significant. In addition, administering the treatment as a second- or third-line therapy appeared to be more appropriate compared with administering it as a later-line therapy; however, this difference was not found to be statistically significant. Therefore, pazopanib should be evaluated as an option for a selected group of patients in whom these factors present together. A further advantage of pazopanib demonstrated was that treatment tolerance was generally good.