Alveolar soft part sarcoma (ASPS) is a very rare soft tissue sarcoma that predominantly affects adolescents and young adults. ASPS is also known resistance to conventional chemotherapy with less than 10% remission rate. Recent reports have showed the response to targeted therapies in ASPS. The purpose of this study is to evaluate the activity of pazopanib in patients with metastatic ASPS.
Since November 2011, total nine patients (7 female, 2 male) with metastatic ASPS received pazopanib treatment.
Mean age was 32 years old (range: 23-35). Primary tumor was extremity in six, trunk in two, and head and neck in one. All patients had metastases before starting treatment (9 in lung, 2 in brain and 1 in bone). No patient received prior doxorubicin based chemotherapy. Six patients were treated with pazopanib as first line chemotherapy and the others three with sunitinib followed by pazopanib. The mean treatment duration was 312 days in pazopanib treatment. In evaluable eight patients best RECIST response was PR in two, SD in five and PD in one. The major adverse events included diarrhea in five, hand-foot syndrome in five, hair depigmentation in four and hypertension in three. Two patients discontinued pazopanib treatment due to adverse events. Interestingly, one patient showed tumor regression with not pazopanib, but sunitinib treatment.
Pazopanib showed the clinical efficacy with tolerable adverse events in patients with metastatic ASPS despite its poor doxorubicin-based chemo sensitivity. Although pazopanib may be one of the promising drugs for ASPS like other anti-angiogenic treatment, clinical trial is warranted to establish an evidence to determine the most optimal treatment.
Clinical trial identification
All authors have declared no conflicts of interest.