The efficacy and safety of apatinib in metastatic alveolar soft part sarcoma: a case series of six patients in one institution

Background: Evidence suggests that advanced or metastatic alveolar soft part sarcoma (ASPS) with high metastatic potential is chemo-resistant. However, the benefits of tyrosine kinase inhibitors have been demonstrated for the treatment of ASPS. Purpose: This study aimed to investigate the efficacy and safety of apatinib, aspecific VEGFR-2 inhibitor, in ASPS patients. This retrospective analysis involved six patients with metastatic ASPS not amenable to curative treatment. Patients and methods: Apatinib was administered at a dose of 500mg per day. Tumor responses were assessed according to the Response Evaluation Criteria in Solid Tumors (RECIST 1.1) guidelines. Survival analysis was performed using the Kaplan–Meier test, and a safety profile was recorded. Results: The mean age of patients was 26.5 (range, 17–32) years. The median progression-free survival (PFS) was 18.53 months (95% CI, 12.23-NE). However, median overall survival (OS) has not been reached. Twenty-four month PFS and OS rates were 50.0% and 100.0%, respectively. One patient achieved a complete response, and the remaining patients achieved partial responses, with an objective response rate of 100%. Median follow-up was 20.6 (range, 12.43–34.13) months. The most common adverse events included gastrointestinal discomfort (4/6[66.7%]), hair hypopigmentation (4/6[66.7%]) and hand-foot skin reaction (3/6[50.0%]). Conclusion: Apatinib shows beneficial activity in metastatic ASPS patients, and further studies are warranted with more cases and longer follow-up periods to fully characterize clinical efficacy and safety of apatinib in ASPS.