Dramatic response to alectinib in a lung adenocarcinoma patient harboring a Novel SSFA2-ALK fusion

ALK (anaplastic lymphoma kinase) gene rearrangements have been reported in 3-5% of NSCLC patients. Different ALK fusion forms can mediate different downstream signaling pathways and may exhibit different sensitivities to ALK tyrosine kinase inhibitors (TKIs). To identify more fusion partners that are sensitive to ALK-TKIs, we present a case of 46-year-old woman with stage IV lung adenocarcinoma. NGS panel analysis suggested that a novel SSFA2-ALK fusion was identified in this patient. Moreover, this fusion was validated through IHC (VENTANA ALK (D5F3) antibody) and FISH (ZytoLight ALK Break Apart FISH Probe). Importantly, to the best of our knowledge, there is no report about SSFA2-ALK fusion in solid cancers. Moreover, the patient achieved an admirable response to alectinib, with a clinical evaluation of complete response (CR). In summary, our findings expand the spectrum of ALK fusion patterns and provide robust evidence for the precise administration of alectinib in the future.