Oral arsenic trioxide-based maintenance regimens for first complete remission of acute promyelocytic leukemia: a 10-year follow-up study.

Seventy-six patients with acute promyelocytic leukemia (APL) in first complete remission after induction and consolidation by daunorubicin and cytosine arabinoside received oral arsenic trioxide (As(2)O(3))-based maintenance. Three regimens were used: oral As(2)O(3) (10 mg/day, regimen A, n = 20), oral As(2)O(3) plus all-trans retinoic acid (ATRA, 45 mg/m(2) per day, regimen AA, n = 19), and oral As(2)O(3) plus ATRA plus ascorbic acid (1000 mg/day, regimen AAA, n = 37), each given for 2 weeks every 2 months for 2 years. Patients receiving A, AA, and AAA maintenance did not differ significantly in clinicopathologic features and risk factors. Headache, dyspepsia, reversible liver function derangement, and herpes zoster reactivation were adverse effects observed during maintenance. QTc prolongation and arrhythmias were not encountered. At a median follow-up of 24 months (range, 1-115 months), there were 8 relapses. The 3-year leukemia-free-survival, event-free-survival, and overall-survival were 87.7%, 83.7%, and 90.6%, respectively. Adverse prognostic factors included male gender for leukemia-free-survival, and unrelated cancers for overall survival. Age, presentation WBC count and platelet count, and the type of oral As(2)O(3) maintenance regimens had no impact on survivals. Prolonged oral As(2)O(3) maintenance was feasible and safe and resulted in favorable outcomes when used with a simple induction and consolidation regimen compared with other protocols composed of multiple chemotherapeutic agents.

Intrathecal chemotherapy for hematologic malignancies: drugs and toxicities.

Intrathecal (IT) chemotherapy is an important component of the prophylaxis or treatment of hematologic malignancies in the central nervous system (CNS), especially in patients with acute lymphoblastic leukemia and aggressive lymphomas. Different regimens of IT chemotherapies have been formulated, often in conjunction with systemic high-dose chemotherapy leading to penetration of the drugs into the cerebrospinal fluid (CSF). The three commonest IT drugs are methotrexate, cytosine arabinoside (Ara-C), and corticosteroids. The CSF half-lives of methotrexate and Ara-C are much prolonged, a factor to be considered if these drugs are also administered systemically in high doses. Neurotoxicities attributed to IT chemotherapy have been reported, including spinal cord lesions, seizures, and encephalopathy. Spinal cord lesions, manifesting as tetraplegia, paraplegia, and cauda equina syndrome, are the commonest neurotoxicity. It is mostly related to combined IT methotrexate and Ara-C, or Ara-C as the sole IT agent when given at high doses or as a slow-release preparation. Cord lesions rarely recover and patients are left with motor deficits, bowel and urinary disabilities. Seizures and encephalopathy are reported in relatively fewer patients, with variable manifestations and prognosis. Knowledge of the pharmacokinetics, dosing schedules and potential toxicities of IT chemotherapeutic drugs is important in the design of CNS prophylaxis and treatment in hematologic malignancies.