Advanced ALK-EML4 fusion-positive non-small cell lung cancer with intraspinal metastases: a case report

Among non-small cell lung cancer (NSCLC) cases, anaplastic lymphoma kinase (ALK)-positive disease is characterized by a chromosomal rearrangement that generates an oncogenic ALK fusion gene, occurring in approximately 2-11% of patients. ALK-positive NSCLC is associated with a high incidence of brain metastases, with at least 20% of patients presenting with brain metastases at the time of diagnosis. Conversely, intraspinal metastasis is an uncommon site of metastatic involvement in patients with NSCLC. When intraspinal metastases invade the lumbar spinal canal, they may cause low back pain as well as neurological symptoms and signs in the lower limbs. Herein, we report a case of intraspinal metastasis in a patient with ALK-EML4 fusion-positive lung adenocarcinoma. Notably, at the time of initial relapse, molecular profiling failed to detect any mutations in the epidermal growth factor receptor (EGFR) or ALK genes. However, next-generation sequencing performed at the third recurrence confirmed the presence of the ALK-EML4 fusion mutation. Following the fifth disease recurrence, the patient received palliative radiotherapy followed by combination targeted therapy with lorlatinib and anlotinib, and subsequently transitioned to maintenance therapy with lorlatinib, achieving an overall survival of 121 months (right-censored, t+) and a duration of treatment of 48 months (t+) with lorlatinib as fifth-line therapy.