Chemotherapy in alveolar soft part sarcomas. What do we know?

Alveolar soft part sarcoma (ASPS) is a rare tumour. Published series about treatment and outcome are scarce. Conclusive data about the response to chemotherapy are not available. The aim of this study was to analyse the efficacy of palliative chemotherapeutic treatment options and the incidence and mode of presentation of brain metastases. We retrospectively analysed our own sarcoma data-base and reviewed the literature. From our registry containing 757 patients, we identified 8 patients with ASPS. From the literature, 47 cases of adult patients and 13 children with sufficient data about chemotherapy were identified. Response to first-line chemotherapy in 68 patients was: complete remission (CR) 4%, partial remission (PR) 3%, stable disease (SD) 41%, progressive disease (PD) 51%. 285 patients with stage IV disease were evaluable for the analysis of metastatic sites. The incidence of brain metastases was 30.5% (87/285). Brain metastases were detected at a median interval of 48 months (range 0-396 months) after the primary diagnosis. Median survival after the diagnosis of brain metastases was 12 months. The median survival for patients with stage IV disease treated by chemotherapy was 36+ months (range 10-132 months) (31 patients evaluable) with a median follow-up of 46 months (range 10-135 months). ASPS shows a high incidence of brain metastases, at least 3 times higher than that of other soft tissue sarcomas. Chemotherapeutic regimens used for the treatment of other soft tissue sarcomas lack efficacy in ASPS. Staging investigations for ASPS should routinely include imaging of the brain. ASPS patients should not be treated with chemotherapy outside of controlled clinical trials. New targets for specific biologically-directed therapies need to be developed.