Clinical improvement and survival in breast cancer leptomeningeal metastasis correlate with the cytologic response to intrathecal chemotherapy.

Leptomeningeal meningitis occurs in approximately 5% of metastatic breast cancers, and there is no standard treatment for this complication. We retrospectively analyzed the clinical data and cerebrospinal fluid of 24 patients treated with high-dose intrathecal methotrexate for breast cancer leptomeningeal meningitis (BLM). Cytologic response (CSF cytology without neoplastic cells after treatment) was observed in 11 patients (46%) and related to survival (P = 0.005). In addition, clinical symptoms improved in all 11 patients who had a cytologic response and in 7 patients (54%) without cytologic response (P = 0.02). The predictive value of cytologic response needs further confirmation. Cytologic response could be helpful in the management of intrathecal chemotherapy in patients with BLM.