Treatment outcomes of sunitinib and/or pazopanib in advanced alveolar soft part sarcoma: A Turkish Oncology Group (TOG) study

Alveolar soft part sarcoma (ASPS) is an ultra-rare, highly angiogenic sarcoma with limited responsiveness to chemotherapy. Tyrosine kinase inhibitors (TKIs) such as sunitinib and pazopanib have shown promising activity, but comparative real-world data remain scarce. This multicenter, retrospective study included 51 patients with metastatic ASPS treated with sunitinib and/or pazopanib between January 2013 and March 2025. Progression-free survival (PFS) and overall survival (OS) were analyzed using Kaplan-Meier methods, and prognostic factors were assessed via Cox regression. First-line TKI therapy achieved significantly longer median PFS compared with chemotherapy (24.9 vs. 5.8 months; p < 0.001), without a significant OS difference. In first-line comparisons, pazopanib demonstrated a trend toward longer PFS (27.2 vs. 15.2 months; p = 0.052) and significantly prolonged OS (45.0 vs. 21.0 months; p = 0.021) versus sunitinib. Across all lines, median PFS and OS were 24.9 and 38.3 months for pazopanib, and 17.7 and 21.0 months for sunitinib, respectively. Multivariate analysis identified prior chemotherapy and liver metastases as independent predictors of shorter PFS. Both agents were well tolerated, with mostly Grade 1-2 toxicities. In one of the largest real-world ASPS cohorts, frontline TKIs provided substantial disease control and prolonged survival compared with chemotherapy, with manageable toxicity. These findings reinforce the role of anti-angiogenic therapy as a preferred first-line approach in advanced ASPS. Prospective studies are warranted to optimize treatment sequencing in this ultra-rare sarcoma.