Pazopanib treatment slows progression and stabilizes disease in patients with taxane-resistant cutaneous angiosarcoma

Although cutaneous angiosarcoma (cAS) has one of the worst prognoses among malignant skin tumors, few effective drug options for secondary treatment have been discovered to date because of the limited number of cases. Therefore, this study was aimed at determining pazopanib's potential as a new cAS treatment option. We retrospectively evaluated five patients with taxane-resistant unresectable cAS treated with pazopanib at a university hospital. Their characteristics and treatment outcomes were retrieved from their records. Progression-free survival (PFS), overall survival (OS), disease progression, and toxicity were evaluated; furthermore, the response to pazopanib was assessed in relation to the expression of vascular endothelial growth factor receptor 2 (VEGFR-2). The median PFS from the time of pazopanib initiation was 94 days. Two patients showed partial response, two showed stable disease, and one had progressive disease in the case of the best overall response. VEGFR-2 expression was positive in all cases, and patients with high expression had improved median OS compared to that in those with low expression. VEGFR-2 expression was correlated with a longer OS. The most common toxicities were hypertension and anorexia followed by myelosuppression. This is the largest case series reported wherein pazopanib was used for taxane-resistant cAS. Although the cytoreductive effect and survival benefits were not significant in this small sample, we consider pazopanib a valid treatment option for preserving patients' quality of life. Our results suggest pazopanib treatment slows the progression of disease and stabilizes it in patients with taxane-resistant cAS.