Preoperative Treatment With Pazopanib in a Case of Chemotherapy‐Resistant Infantile Fibrosarcoma

Abstract

Clinical and radiological diagnosis of infantile fibrosarcoma (IFS) is challenging because of its similarity to vascular origin tumors. Treatment involves complete resection. Although chemotherapy may allow more conservative resection, treatment guidelines are not strictly defined. One IFS patient with an unresectable tumor had disease progression during chemotherapy. A primary tumor sample showed high VEGFR-1/2/3 and PDGFR-α/β expression. After pazopanib therapy, most tumor showed necrosis within 29 days and could be removed completely, with no relapse in 8 months post-resection. When IFS features hypervascularity, VEGFR and PDGFR expression may be high, thus allowing consideration of VEGFR inhibitors such as pazopanib.

Infantile fibrosarcoma–like tumor driven by novel RBPMS-MET fusion consolidated with cabozantinib

“…More recently, three patients with refractory IFS associated with LMNA-NTRK1 fusions were successfully treated with the oral MET/ALK/ROS1 tyrosine kinase inhibitor (TKI) crizotinib (Mody et al 2015;Wong et al 2016;Bender et al 2019), buoyed by in vitro data of its action against TrkA (Vaishnavi et al 2013). Additionally, an infant with ETV6-NTRK3 fusion-positive IFS responded to pazopanib suspension administered preoperatively (Yanagisawa et al 2016).…”

Analysis of infantile fibrosarcoma reveals extensive T‐cell responses within tumors: Implications for immunotherapy

“…The overall therapeutic response to these therapies are about 90%, but local relapse or even metastatic progression remains possible in about 10% patients. More specific therapies, such as targeted therapies against the activation of chimeric fusion proteins or tumor angiogenesis, may play more important roles in treating traditional therapy‐resistant IFS patients. However, it remains unclear if the recent success in cancer immunotherapy can be applied to treating traditional therapy‐resistant IFS patients.…”

Successful treatment of ETV6‐NTRK3 fusion gene‐negative infantile fibrosarcoma with metastatic lesion resistant to VAC chemotherapy

“…Tropomyosin-related kinase inhibitor LOXO-101 and pazopanib have been found to be effective for chemotherapy-resistant IFS with ETV6-NTRK3 fusion. 4,5 Regarding ETV6-NTRK3 fusion-negative IFS, the actual response rate to chemotherapy cannot be assessed accurately, because the number of cases of failure to respond to chemotherapy could be underreported in the literature. In this study, VID second-line chemotherapy produced a good response, and, despite resistance to VAC chemotherapy, the patient was cured using a combination of surgical excision and VID.…”