Clinical Efficacy of Afatinib Treatment for a Patient with Leptomeningeal Carcinomatosis

Leptomeningeal metastases occur in 1% of patients with non-small-cell lung cancer. There have been several reports on the treatment of leptomeningeal metastases with afatinib. Our patient was a 41-year-old woman who had never smoked and was diagnosed with stage IV adenocarcinoma of the lung with an epidermal growth factor receptor (EGFR) mutation. She was treated with afatinib for the recurrence of leptomeningeal metastases. After the treatment with afatinib was initiated, the neurological symptoms dramatically regressed, and she achieved progression-free survival for 7 months. The concentration of afatinib in the cerebrospinal fluid (CSF) ranged from 0.05 to 0.14 ng/mL, and the penetration rate of afatinib from the plasma to the CSF ranged from 0.28 to 0.40%. This concentration might be sufficient to achieve a clinical effect for leptomeningeal carcinomatosis. Therefore, afatinib administered at the usual doses may be an effective treatment for leptomeningeal carcinomatosis of EGFR-mutated or EGFR-tyrosine kinase inhibitor-sensitive lung adenocarcinoma.