ALK-G1269A mutation in epithelioid inflammatory myofibroblastic sarcoma after progression on crizotinib: A case report.

Epithelioid inflammatory myofibroblastic sarcoma (EIMS), a specific subtype of inflammatory myofibroblastic tumors (IMT), is a relatively rare malignant mesenchymal tumor with clinical features of positive anaplastic lymphoma kinase (ALK), high invasiveness, treatment resistance and poor prognosis. Therefore, ALK inhibitors represent specific effective drugs for patients with this type of tumor. However, acquired resistance remains inevitable without a clear mechanism of action and therapeutic strategy to counteract this. Herein, a chromosomal ALK-G1269A mutation was identified using next-generation sequencing (NGS) and the mutation was confirmed by Sanger sequencing in a patient with crizotinib-resistant EIMS who benefited from treatment with the second-generation ALK inhibitor AP26113. To the best of our knowledge, a few rare cases of crizotinib-resistance in IMTs have been reported, and there are no reported cases in EIMS. In this article, we present the case of a patient with a secondary mutation of ALK-G1269A in EIMS, and suggest that AP26113 (Brigatinib) may represent an ideal treatment for these patients.