Identification of triple gene fusion ALK-LRRN2, LTBP1-ALK, and HIP1-ALK in advanced lung adenocarcinoma and response to alectinib: A case report

RATIONALE: Anaplastic lymphoma kinase (ALK) rearrangement is the second most common targetable oncogene-dirven gene in nonsmall cell lung cancer. Owing to the advanced sequencing technologies, new partner genes of ALK have been constantly detected. PATIENT CONCERNS: A 42-year-old Chinese woman went to our hospital with the chief complaint of cough and expectoration for 1 month. The patient had no fever, chest pain, and hemoptysis. DIAGNOSES: She was diagnosed with advanced lung adenocarcinoma. The patient underwent lung biopsy guided by computed tomography and pathology showed poorly differentiated adenocarcinoma. To explore possibility of targeted therapy, the tumor samples were subjected to next-generation sequencing, and a rare 3 ALK fusion variant ALK-LRRN2, LTBP1-ALK, and HIP1-ALK was identified. INTERVENTIONS AND OUTCOMES: The patient subsequently received alectinib treatment, and achieved partial response. No significant drug related adverse reactions were found during alectinib treatment. The progression-free survival achieved 25 months. LESSONS: Together, we identified a rare triple ALK fusion variant, ALK-LRRN2, LTBP1-ALK and HIP1-ALK, in a patient with lung adenocarcinoma. The patient benefited from alectinib treatment, which could provide a certain reference for the patients with such gene alteration.