Pleomorphic rhabdomyosarcoma, outcomes of patients with advanced disease treated with systemic agents
The global pushing ultra-rare sarcomas towards hope (PUSH) consortium of investigators conducted an analysis of database records of patients confirmed to have pleomorphic rhabdomyosarcoma at 21 sarcoma centers from around the world from 2013-2023 to determine the outcomes patients treated with systemic therapies. They analyzed a total of 77 patients and found that from the start of treatment anthracycline-based treatments (chemotherapies that work through a variety of ways to stop tumor growth) had a 50% objective response rate, with median progression free survival of 5.2 months and median overall survival of 19.2 months. Gemcitabine-based treatments (a chemotherapy that interferes with DNA synthesis) had a 42% objective response rate with a median progression free survival of 3.7 months and a median overall survival of 7.8 months. Additionally, pazopanib (a drug that selectively block proteins called tyrosine kinases) had a 33% objective response rate with median progression free survival of 2.4 months and a median overall survival of 4.2 months.
Although retrospective and observational, these analyses indicate that pazopanib, and anthracycline- and gemcitabine-based regimens may have activity in patients with pleomorphic rhabdomyosarcoma. Further research is necessary and prospective validation is planned.