Case report: A Novel Intergenic KIF5B-MET Fusion Variant in a Patient with Gastric Cancer

BackgroundMET fusion is a key driver mutation, but it is rare in gastric cancer (GC). Several MET inhibitors have been approved for the treatment of MET-positive patients, but the tumor response is heterogeneous. With the development of next-generation sequencing (NGS), diverse MET fusion partner genes have been identified. We reported a case of a fusion variant involving KIF5B-MET in GC.Case presentationAfter thoracoscopic inferior lobectomy plus lymph node dissection under general anesthesia, a “tumor within a tumor” was found in the lung tumor tissue of a 64-year-old nonsmoker male patient. Combining the medical history and the results of enzyme labeling, the focal area was considered to be GC. To seek potential therapeutic regimens, an intergenic region between KIF5B and MET fusion was identified. This fusion contains a MET kinase domain and coil-coiled domains encoded by KIF5B exons 1-25, which might drive oncogenesis. ConclusionOur founding could extend the spectrum and genomic landscape of MET fusions in GC and favor the development of personalized therapy.