Clinical outcome and efficacy of current anti-leukemic therapy for leptomeningeal involvement in acute myeloid leukemia

We investigated risk factors and outcome in acute myeloid leukemia (AML) patients with leptomeningeal involvement. Medical records of patients with non-promyelocytic AML at Seoul National University Hospital from January of 2000 to November of 2013 were reviewed. Leptomeningeal involvement was defined as the presence of atypical or malignant hematopoietic cells in the cerebrospinal fluid. Among 775 patients with AML, 141 patients (18.2 %) underwent cerebrospinal fluid examination. Leptomeningeal involvement of AML, confirmed in 38 patients (4.9 %), was associated with high white blood cell count and high level of lactic. There were seven patients in the favorable risk group (19.4 %), 21 in the intermediate risk group (58.3 %), and eight in the adverse risk group (22.2 %). Twenty-eight patients (85.7 %) developed leptomeningeal involvement during relapse status or refractory status. Thirty-one patients (81.6 %) received intrathecal chemotherapy, and whole-brain and/or craniospinal radiotherapy was conducted in 10 patients (27.0 %). The rate of complete remission after induction chemotherapy was 63.2 %. Median overall survival was 9.9 months. Radiotherapy and complete remission after the first induction chemotherapy were associated with longer overall survival. Leptomeningeal involvement in acute myeloid leukemia is rare, but relatively common in relapsed status or refractory status. Craniospinal radiotherapy and complete remission after induction chemotherapy were found to favorable prognostic factors.