Identification of a Novel SLC8A1-ALK Fusion and Non-Canonical Expression Significantly Responding to ALK-TKIs in Lung Adenocarcinoma: A Case Report

A novel SLC8A1-ALK fusion in lung adenocarcinoma confers sensitivity to alectinib: A case report

ALK fusion genes are diverse. Approximately 30 different ALK fusion protein partners have been described previously, and some of these fusion proteins have been reported to be effective against ALK-tyrosine kinase inhibitor (TKI). ALK rearrangements often occur at a common breakpoint in exon 20 of the genome. SLC8A1-ALK, a novel fusion protein partner, comes from exon 2 of the SLC8A1 gene rearranged with exon 20 of the ALK gene. Here, we reported a patient with advanced lung adenocarcinoma harboring a SLC8A1-ALK fusion who benefited from first-line treatment with alectinib. After 2 months of taking alectinib, the targeted lung lesions and intrahepatic metastases regressed significantly. To date, the patient has achieved nearly 1 year of progression-free survival while taking the drug. Given the diversity of ALK fusion genes and the different efficacy of ALK-TKIs, we believe that this case report has an important clinical reference.

A novel SLC8A1/LINC01913 intergenic region-ALK fusion identified by NGS and validated by IHC and FISH in a stage IIB lung adenocarcinoma patient who remains relapse-free during the treatment of crizotinib: a case report

In resected non-small cell lung cancer (NSCLC), ALK rearrangements are associated with worse recurrence-free survival (RFS) than other driver genes. In addition, the micropapillary pattern of NSCLC is associated with a poor prognosis. In recent years, crizotinib tyrosine kinase inhibitors (TKIs) have been widely used to treat patients with advanced NSCLC with ALK fusion. Patient survival outcomes have become highly promising, reflecting the necessity of exploring the application of ALK-TKIs in resected, early stage NSCLC with ALK rearrangements. A 60-year-old Chinese man was diagnosed with stage IIB lung adenocarcinoma harboring a novel SLC8A1/LINC01913 intergenic region-ALK fusion identified by NGS and validated by immunohistochemical staining (IHC) and fluorescence in situ hybridization (FISH). Crizotinib (250 mg orally once daily) was administered to the patient following surgery. The patient remained relapse-free after four months and seven months. This report provided a valuable treatment plan for early lung adenocarcinoma patients with high risks to prevent a postoperative recurrence.