PDGFRA amplification could be a poor prognostic factor of advanced undifferentiated pleomorphic sarcoma in a comprehensive genomic profiling cohort

Background Undifferentiated pleomorphic sarcoma (UPS) is the most common pleomorphic sarcoma, and its genomic landscape has been analyzed, albeit in small numbers. This study aimed to clarify the relationship between gene variants and the prognosis of patients with advanced UPS. Methods This retrospective cohort study was conducted to analyze the data of patients with advanced UPS using a registry of the Center for Cancer Genomics and Advanced Therapeutics (C-CAT) database up to Oct 2025 in Japan, analyzed using comprehensive genomic profiling assay. Results A total of 233 patients with advanced UPS were identified in the C-CAT database; 151 men (64.8%), median age: 60.2 years. TP53 variant (55%) was the most frequent event, and the rate of PDGFRA and KDR amplification were 9% and 6%, respectively. PDGFRA amplification co-occurred with KDR amplification ( P  < 0.001). Survival from the initiation of chemotherapy was analyzed by adjusting for length bias inherent in the database using the Kaplan–Meier estimator, an established method of adjustment. Patients with PDGFRA amplification (11 patients) had a worse prognosis than those without PDGFRA amplification [hazard ratio 2.9, 95% confidence interval 1.2–6.9 ( P = 0.02 )]. TP53 alterations ( P = 0.24 ) were not associated with prognosis. In addition, treatment time with pazopanib with PDGFRA amplification [4 patients, 2.3 months (1.2–11.2 months)] was not different with those without PDGFRA amplification [28 patients, 3.8 months (0.9 months–not reached)] ( P  = 0.52). Conclusions For patients with advanced UPS, PDGFRA amplification was a poor prognostic factor, and is not related to the efficacy of pazopanib treatment.