[Acute leukemia]

Within a few years of the introduction of effective systemic chemotherapy for the treatment of acute leukemia, central nervous system (CNS) leukemia emerged as a significant problem. The strategy for treatment of leukemia is that one achieves cure by destruction of all leukemic cells, through this cannot be verified with present technology. The incidence of CNS-leukemia and the factors influencing this complication have been studied in a group of 131 cases with acute childhood leukemia. The overall incidence of CNS-leukemia was 30% in acute lymphocytic leukemia (ALL), 8% in acute myeloblastic leukemia (AML). However, cumulative incidence of CNS-leukemia calculated by modified Life-Table Method showed 56.8% in children who survived over 48 months after diagnosis of ALL. It was considered that the chief cause of the increased incidence of this complication was prolongation of survival. The CNS-leukemia was significantly greater in patients with under 10 year of age (p greater than 0.05), high initial leukemic cell counts (p less than 0.025), high appearance rate of leukemic cells in peripheral blood (over 50%) (p less than 0.005), and hepatosplenomegaly, especially lymph node enlargement (p less than 0.05). Blood-borne metastasis was considered to be probably the chief route of leukemic infiltration to the CNS. Between 1972 and 1978, 153 children with ALL were treated with multiple methods of CNS-prophylaxis, and were analyzed in relation to treatment regimens, age, sex and initial hematologic status. Patients received CNS-prophylaxis; Group I: three doses of intrathecal methotrexate (MTX 12 mg/m2) and hydrocortisone (HDC 12 mg/m2), Group II: same as in Group I followed by cyclic MTX and HDC, Group III: same as in Group I plus 2,400 rads of cranial irradiation. CNS-leukemia terminated complete remission 25 of 153 patients (16.3%). The cumulative incidence of CNS-leukemia at 4 year calculated by the Kaplan-Meier Method was 40.5% in Group I, 26.9% in Group II, and 14.5% in Group III. Development of CNS-leukemia was more frequent in male than in female (p less than 0.05), and in patients with initial high leukocyte counts (WBC greater than 25,000/mm3). We conclude that the combination of cranial irradiation and intrathecal MTX and HDC was highly efficacious. However, more intensive CNS-prophylaxis should be needed for such a high risk patients in male with high initial WBC.(ABSTRACT TRUNCATED AT 400 WORDS)