A novel RET fusion in non-small cell lung cancer identified by next-generation sequencing: a case report.

REarranged during Transfection (RET) gene fusion is one of the common oncogenic variants in non-small cell lung cancers (NSCLCs). However, few RET fusion-positive cases have partner intergenic-breakpoint fusions, in which the partner breakpoint localizes to intergenic regions. Here, we report a 40-year-old Chinese female non-smoker diagnosed with minimally invasive lung adenocarcinomas (pT1bN0M0, stage IA). Targeted next-generation sequencing revealed a rare form of RET fusion in the cancerous tissue, in which an intergenic fragment upstream multiple inositol-polyphosphate phosphatase 1 gene was fused with the tyrosine kinase domain in RET. The result was validated by fluorescence in situ hybridization. To our knowledge, this novel form of RET fusion in NSCLC is reported for the first time, which expands the alteration spectrum and paves the way for the future development of specific targeted therapies.