Intra-CSF Topotecan in Treatment of Breast Cancer Patients with Leptomeningeal Metastases

Background There are few treatment options for patients with leptomeningeal metastases (LM). Methods We report a case series of patients with breast cancer and LM treated with intra-CSF topotecan (TOPO). Outcome was assessed by clinical exam and MRI at baseline, at end of induction (4-5 weeks), then every 3 months; CSF cytology was determined at baseline and with each treatment. Results Thirty-one women [median age, 58 (37-81); median KPS 60 (40-100)] received treatment. At baseline, 68% had positive CSF cytology, and 90%, leptomeningeal enhancement on MRI. 84% of patients also received focal RT (not during TOPO) and 77% received concomitant systemic hormonal or chemotherapy. Median number of TOPO treatments was 14.5 (range, 3-71); median duration of treatment, 11 weeks (1-176); and median OS, 6.9 months (range, 0.9-48.8). Patients remaining progression-free during 4-6 weeks of induction (81%) had a median OS of 11.5 months (range, 1.8-48.8). Overall neurologic PFS at 6, 12, and 24 months was 39%, 26%, and 6%, respectively. Clearing of CSF malignant cells for >3 consecutive samples occurred in 10/21 (48%) patients with positive CSF cytology at baseline, remaining clear for a median duration of 15.9 months (range, 1.4-34.5). Grade 3 adverse events included headache or vomiting (3pts), T2 hyperintensity surrounding the ventricular catheter (2 pts), and meningitis (2 pts). Conclusions Intra-CSF TOPO, with focal RT as needed for symptomatic areas of enhancement produced durable clearing of CSF malignant cells in 48% of patients positive at baseline, with promising median PFS and OS.