Successful treatment of 2 patients with brain metastases from non-small cell lung cancer with epidermal growth factor receptor mutation receiving dacomitinib: A case report

Rationale: Approximately 20% of patients with non-small cell lung cancer (NSCLC) are diagnosed with brain metastasis, which is related to poor survival outcomes. The ability of tyrosine kinase inhibitor drugs to penetrate the blood-brain barrier makes them a potential option for intracranial metastases. Dacomitinib, an irreversible second-generation pan-HER tyrosine kinase inhibitor, has become a standard therapy for patients with epidermal growth factor receptor mutations. However, its efficacy in patients with brain metastases (BMs) is not yet established. Here, we present 2 patients with epidermal growth factor receptor-mutant NSCLC with brain metastasis. After initiation of dacomitinib as first-line treatment, a significant clinical response was achieved, and a long-lasting complete remission was achieved in 1 patient up to this date.

Patient concern: Case 1 was a 47-year-old man who was admittedtothe hospital because of recurrent cough and expectoration for >1 year. Chest computed tomography scans revealed a high-density shadow in the left upper lobe. Cranial magnetic resonance imaging indicated an abnormal nodular enhancement in the right cerebellar hemisphere. Case 2 was a 55-year-old man with a chief complaint of intermittent cough and expectoration for >1 month. Chest computed tomography revealed a high-density mass in the left superior lobe. Magnetic resonance imaging of the central nervous system revealed 2 abnormal nodular enhancements in the left frontal lobe.

Diagnosis: Both patients were diagnosed with lung adenocarcinoma by bronchoscopy and lymph node biopsy.

Interventions: Both patients received dacomitinib 30 mg once daily as first-line therapy for 8 and 11 months, respectively until disease progression.

Outcome: After treatment with dacomitinib, both patients achieved complete response in BMs. Progression-free survival was 11 and 8 months, respectively.

Lessons: Dacomitinib strongly controlled BMs in patients with advanced NSCLC, and the adverse reactions were tolerable. Dacomitinib may be considered a new treatment option for these patients. Further prospective studies are recommended to confirm this conclusion.