AIM To evaluate the efficacy of intracerebrospinal fluid (intra-CSF) thiotepa in patients with leptomeningeal metastasis (LM) after failure of a methotrexate-based treatment.

PATIENTS AND METHODS We retrospectively reviewed the medical records of patients with LM who received 10 mg of intra-CSF thiotepa twice a week.

RESULTS Out of 40 patients, 25 were females (63%), and 31 (78%) had an Eastern Cooperative Oncology Group performance status (ECOG PS) ≥2. Fourteen out of the 30 evaluable patients (47%) had a cytological response to intra-CSF thiotepa. The median overall survival (OS) after treatment with thiotepa was 19.4 weeks (95% confidence interval (CI)=15.3-23.5). Grade 3 toxicities were thrombocytopenia (N=2), bacterial meningitis (N=2), and pneumonia (N=1). According to a multivariate analysis, an ECOG PS ≥2 (hazard ratio (HR)=5.11, 95% CI=1.39-18.80, p=0.014), clinical improvement (HR=0.09, 95% CI=0.03-0.29, p<0.001), and radiation for LM after intra-CSF thiotepa (HR=0.33, 95% CI=0.11-0.97, p=0.043) were independently associated with survival.

CONCLUSION Intra-CSF thiotepa seems to be a meaningful salvage treatment for patients with LM whose disease progresses after a methotrexate-based treatment.