Prolonged Survival of a Patient with Chronic Myeloid Leukemia in Accelerated Phase with Recurrent Isolated Central Nervous System Blast Crisis

BACKGROUND Chronic myeloid leukemia (CML) is usually a tri-phasic myeloproliferative neoplasm, characterized by the presence of the BCR-ABL1 fusion gene, derived from a balanced translocation, t(9;22)(q34;q11). BCR-ABL tyrosine kinase inhibitors (TKI) are used to treat patients with CML. The addition of pegylated interferon-alpha2b to imatinib or dasatinib results in promising deep molecular responses. Because imatinib shows poor penetration into the central nervous system (CNS), the CNS may become a sanctuary site in patients on prolonged imatinib therapy for CML. It is extremely rare for the blast phase in patients with chronic phase CML to affect the CNS without concomitant bone marrow involvement. CASE REPORT This report describes a 57-year-old woman who was diagnosed with accelerated phase (AP) CML and failed high dose imatinib therapy. Despite achieving an excellent molecular response to dasatinib in 6 months, she developed recurrent isolated CNS blast crisis. Survival was prolonged after treatment with intrathecal chemotherapy and whole-brain radiation therapy combined with dasatinib. After achieving long and deep molecular remission with dasatinib and a few months of pegylated interferon-alpha2a, she lived for 18 months in treatment-free-remission (TFR). At age 65 years, she died of progressive rectal carcinoma with septic shock, cancer-related venous thromboembolism, and a possible autoimmune disorder. CONCLUSIONS This patient with accelerated phase CML and 2 isolated CNS blast crises died in TFR 8.5 years after her initial diagnosis and 7.5 years after her first isolated CNS blast crisis. Survival resulted from tailoring of therapies around her comorbidities.