Abstract
BACKGROUND: Patients with relapsed or refractory soft tissue and bone sarcomas have dismal outcomes. Multi-targeted kinase inhibitors (mTKI) have proven to be potent agents in several malignancies, both as primer therapy and as a salvage option. Our aim was to evaluate the clinical outcomes of mTKI treatment in a heterogeneous group of pediatric sarcoma patients retrospectively. PROCEDURES: A total of 18 patients were treated with sorafenib, regorafenib, or pazopanib; 13 of them had osteosarcoma (OSC), 3 had synovial sarcoma (SySa), and 1-1 patient had chondrosarcoma and rhabdomyosarcoma. Indication for mTKI treatment was primarily progressive, inoperable, relapsed, or chemotherapy-resistant disease after completion of first- and second-line chemotherapy. RESULTS: At the time of the beginning of mTKI treatment, the median age was 16.5 years, and the median time to progression from initiation of mTKI was 4 months. The overall response rate was 16%. We conducted a comparison of the survival outcomes of OSC patients receiving mTKIs against a retrospective, non-randomized control group. Overall survival was evaluated from the time of progression or relapse after second-line treatment to the time of death. The log-rank test revealed a significant difference in the survival distribution between patients receiving mTKIs and those who did not (chi2(1) = 8.13 p = 0.004). We observed benefits from mTKI treatment in 3 SySa patients, with pazopanib demonstrating effectiveness and no progression observed thus far. CONCLUSIONS: Our findings suggest that mTKIs are well-tolerated and can serve as a therapeutic option for refractory bone sarcomas as palliative treatment, aiming to slow disease progression and uphold a good quality of life.