Novel therapeutic options for alveolar soft part sarcoma: antiangiogenic therapy, immunotherapy and beyond

Purpose of review Alveolar soft part sarcoma (ASPS) represent 0.5% of sarcomas, defining a rarest among rare malignancies. It affects young adults, displaying slow-growing mass of the thigh, head and neck, and trunk. Although quite indolent, a majority of cases displays an advanced disease with lung bone or central nervous system metastasis. Complete surgery is the cornerstone of localized ASPS, and advanced diseases poorly respond to chemotherapy. Here discuss recent progress in molecular characterization of ASPS and future prospects of therapeutic approaches. Recent findings ASPS is characterized by a specific oncogenic translocation ASPSCR1-TFE3 that induce hepatocyte growth factor receptor (MET) overexpression, angiogenesis, and immunosuppression in the tumor microenvironment. These specific biological features have encouraged the successful exploration of MET inhibitors, antiangiogenic drugs, and immunotherapy. We reviewed the main tracks of ASPS biology and recent insights from targeted therapies is ASPS mainly driven tyrosine kinase inhibitors (especially antiangiogenics), immune-checkpoint inhibitors, and their combinations. Summary Overall, antiangiogenics and anti Programmed cell death 1/Programmed cell death ligand 1 therapies showed a significant activity in ASPS that warrants additional investigation through randomized trials to validate those results and through ancillary biological studies to better understand resistance mechanisms and biomarkers of response.