Significant Anti‑tumor Effectiveness of Imatinib in C‑ kit Negative Gastrointestinal Stromal Tumor – Case Report

Abstract

Inoperable c-kit negative gastrointestinal stromal tumor (GIST) is commonly considered to be highly resistant to systemic therapy. We present a case of a woman with an abdominal sarcoma-like tumor dia gnosed at the age of 26. The patient underwent several surgical procedures and courses of cytostatic therapy without any substantial effect. Later, the tumor was reclassified as c-kit negative GIST harbouring the mutation in exon 12 of PDGFRA gene. Hence, the therapy with imatinib mesylate was initiated, resulting in partial remission of metastatic lesions and further stabilization of the disease for five yeas to date. We therefore consider imatinib mesylate an appropriate therapy for c-kit negative GIST bearing PDGFRA mutations.

Response to sunitinib of a gastrointestinal stromal tumor with a rare exon 12 PDGFRA mutation

“…For the rare PDGFRA exon 12 mutations, the largest retrospective series to date reported a 50 % objective response rate to imatinib in 8 GIST cases with an exon 12 mutation [ 5 ]. Additionally, 1 of 1 patient with PDGFRA exon 12 mutation on a phase III clinical trial, and 1 additional case report of GIST with exon 12 mutation noted a good response to imatinib [ 7 , 8 ].…”