A novel alectinib-sensitive CTNND1-ALK fusion in a lung adenocarcinoma patient: a case report

Genomic fusions of anaplastic lymphoma kinase (ALK) are a well-established therapeutic target in non-small-cell lung cancer (NSCLC). Although various ALK fusion variants have been identified in NSCLC, their responses to ALK tyrosine-kinase inhibitors (TKIs) are heterogeneous. We report the case of a 71-year-old female patient diagnosed with lung adenocarcinoma with liver metastases. A novel CTNND1 (exon 14)-ALK (exon 20) fusion was identified from the biopsy sample by next-generation sequencing (NGS) and validated by immunohistochemistry (IHC) staining. Alectinib was administered, and the patient soon achieved partial response (PR). The progression-free survival (PFS) exceeded 15 months as of January 25, 2022. Our findings expand the spectrum of ALK rearrangements and provide a potential treatment option for lung adenocarcinoma patients with CTNND1-ALK fusions.