Case Report: Long-term survival with erlotinib for lung cancer with secondary leptomeningeal carcinomatosis.

Erlotinib is an epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor, effective as treatment for advanced non-small cell lung cancer; however, no quality evidence of its benefit in leptomeningeal carcinomatosis has been reported. Previous case series suggest that higher doses are more effective, if higher concentrations reach the central nervous system. Here, we present the case of a 42-year-old Chilean patient with EGFR-mutant lung cancer and leptomeningeal metastasis. A multimodal treatment was performed with intrathecal chemotherapy, craniospinal radiotherapy and erlotinib (150 mg/day) for 5 years. At the time of this publication, she remained disease-free, and no EGFR mutation was detected via liquid biopsy. Further investigation is needed to determine the optimal anti EGFR regimen, the intrathecal chemotherapy protocol, and their sequencing. It is also of particular interest to identify factors associated with disease progression, and which are predictors of a good response to tyrosine kinase inhibitor among such patients.