Efficacy of sorafenib in heavily pretreated adult patients with metastatic osteosarcoma.

Abstract

e23511 Background: Osteosarcoma is a rare tumor and is commonly seen in young people. It arises from bone and rarely from soft tissue. Surgery is the primary treatment option for osteosarcoma. Osteosarcoma is radioresistant, except for rare variants. The choices of chemotherapy are limited in the treatment of metastatic osteosarcoma. The efficiency data of targetted therapies in metastatic osteosarcoma is limited. This study aimed to evaluate sorafenib's efficacy in adult patients with heavily pretreated metastatic osteosarcoma. Methods: We evaluated the patients aged over 18 years with metastatic osteosarcoma retrospectively. The clinical, pathological, and treatment data of the patients were recorded. We used SPSS 25. version for statistical analysis. Kaplan-Meier and Cox-regression analysis were used for survival analysis. Results: Fifteen patients were included in the study. Ten (66.7%) of the patients were male, and the median age was 25 (range,19-64). The primary localization of the tumor was the lower extremity (53.4%), head and neck (20%), upper extremity (13.3%), and other sites (13.3%), respectively. The most common metastatic sites were lung (93.3%), bone (46.7%,) and other (33.3%), respectively. Before sorafenib, fourteen (93.3%) patients had received at least two different cytotoxic chemotherapy regimens, six (40%) patients palliative radiotherapy. In addition, metastasectomy had performed on eight (53.3%) patients. The median progression-free survival was 5.5 (95% CI, 1.3-9.7) months with sorafenib. The stable response was observed in 8 (50%) patients and progressive disease 8 (50%) patients. Grade 1-2 toxicities were observed in 50% of the patients, and grade 3-4 toxicities in 14.3% of the patients. Conclusions: In the study, we showed real-life outcomes of sorafenib for disease control in heavily pretreated adult patients with metastatic osteosarcoma. Sorafenib was effective and well-tolerated in the patients. Sorafenib may be considered as a treatment option after chemotherapy in patients with metastatic osteosarcoma.