Advanced Alveolar Soft Part Sarcoma with CNS Metastases Response after Treatment with Atezolizumab: A Case Report

Alveolar Soft-Part Sarcoma (ASPS) is a rare subtype of Soft Tissue Sarcoma (STS). The median age of ASPS patients is 25 years old. Conventional chemotherapy treatments are ineffective in ASPS, and thus, new treatments focus on targeted therapies and immunotherapies. Our patient is a 49-year-old male who presented with right buttock ASPS with diffuse pulmonary and brain metastases. His lesions showed a remarkable response to atezolizumab despite having advanced ASPS with metastatic disease to his lungs and brain. Further study into atezolizumab acting as a first line treatment option for metastatic ASPS is ongoing.