Salvage intracerebrospinal fluid thiotepa in breast cancer-related leptomeningeal metastases: a retrospective case series.

There is currently a paucity of data on salvage intracerebrospinal fluid (intra-CSF) chemotherapy in leptomeningeal metastases (LM). This report is a single-institution experience with salvage treatment in patients with breast cancer (BC) and LM. This retrospective cohort describes 24 consecutive patients with BC selected for a second-line of treatment for LM. The first line of LM treatment consisted of intra-CSF liposomal cytarabine in all patients combined with systemic therapy in 18 cases and radiotherapy in four cases. Second-line (salvage) treatment utilized intra-CSF thiotepa in all and systemic chemotherapy in nine patients. No patient received CNS-directed radiotherapy. The median Eastern Cooperative Oncology Group performance status at initiation of intra-CSF thiotepa treatment was 3 (range 1-4). The median progression-free survival and median survival following intra-CSF thiotepa was 3.1 months (range 3 days-2 years) and 4.0 months (range 6 days-2.5 years), respectively. The median overall survival from LM diagnosis was 9.5 months (range 1.3 months-2.7 years). No grade 3 or higher toxicity was observed. Recognizing the limits of a retrospective study, intra-CSF thiotepa has an acceptable toxicity profile and appears to be a reasonable option for selected BC patients.