A novel intergenic region (chr2: 30,193,816)-ALK fusion shows sensitivity to Alectinib in lung adenocarcinoma

BACKGROUND: Anaplastic lymphoma kinase (ALK) rearrangement, which is mostly showed as fused with echinoderm microtubule-associated protein-like 4 gene (EML4), accounts 3–7% of all common mutations in non-small lung cancer (NSCLC). An intergenic region (chr2: 30,193,816), which located on upstream of the adjacent ALK gene, was never been reported as a ALK patterner before. CASE PRESENTATION: A 56-year-old female patient who had symptoms of persistent cough and shortness of breath visited our facility on April 24, 2022. The chest computerized tomography (CT) examination revealed a massive right hydrothorax. After draining pleural effusion, a hilar mass accompanied multiple nodules in both lungs could been seen in image. Tracheoscopy revealed neoplasm in the medial segment of the middle lobe of the right lung, and the patient was diagnosed as lung adenocarcinoma pathologically. It tested positive for cytokeratin (CK) 7, NapsinA, ALK, and thyroid transcription factor-1 (TTF-1). Next generation sequence testing confirmed the presence of the intergenic region (chr2: 30,193,816)-ALK fusion in the tumor tissue. The patient was subsequently treated with Alectinib, and her symptoms are obviously relieved, the right hilar mass and metastatic nodule were reduced in the reexamination after three months. CONCLUSIONS: The intergenic region (chr2: 30,193,816)-ALK fusion, which is firstly reported in lung adenocarcinoma, is a mutation with expression significance. It shows sensitivity to Alectinib.