Durable Response of Leptomeningeal Metastasis of Breast Cancer to Salvage Intrathecal Etoposide After Methotrexate: A Case Report and Literature Review

Leptomeningeal metastasis (LM) is recently on the rise as one of important clinical issues in the management of metastatic breast cancer (MBC). Clinical research on salvage intrathecal chemotherapy after failure of first-line treatment for MBC patients with LM has rarely been reported.We report the case of a breast cancer patient with LM who showed durable response to salvage intrathecal etoposide subsequent to failure of methotrexate. Etoposide 1 mg was injected through an Ommaya reservoir every week. Corticosteroid was used for a prophylaxis of chemical arachnoiditis. The treatment was successful palliation of LM for 33 weeks without significant adverse effects. Time to neurologic progression was estimated to be about 230 days for the treatment and overall survival was 301 days from the diagnosis of LM.Intrathecal etoposide can be considered as an additional treatment option for LM in breast cancer. Further large clinical studies are necessary to investigate the effectiveness and safety of the treatment.