Intensive chemotherapy in children with acute lymphoblastic leukemia (L‐2 protocol)

Abstract

Seventy-five consecutive children with acute lymphoblastic leukemia (ALL) were treated with a combination drug protocol (L-2) consisting of three phases: remission induction, consolidation, and maintenance. Induction was achieved with prednisone, vincristine (VCR), and Daunorubicin (DNR). For consolidation, arabinosylcytosine (Ara-C), and 6-thioguanine (TG) followed by L-asparaginase and 1,3-bis (2-chloroethyl)-I-nitrosourea (BCNU) were used. Maintenance consisted of administration of TG, cyclophosphamide, hydroxyurea, DNR, methotrexate (MTX), BCNU, Ara-C, and VCR, given as 5-day courses. Patients received periodic injections of intrathecal MTX for “prophylaxis” of the central nervous system (CNS) leukemia throughout the treatment course which was 3 years. Seventy-four children achieved remission. Two died early in remission with serum hepatitis and I was lost to followup. Twelve patients have relapsed; in 2, the relapse was confined to CNS; in l, bone marrow and CNS relapse were concurrent. The remaining 59 have continued in complete remission from 1–42 months. Ten of the 12 children (excluding the hepatitis cases) who were registered on the L-2 protocol for periods of 36 months or more remain free of disease. The height of the initial white blood cell count was found to be strongly related to the duration of complete remission. Tolerance to this regimen was generally good, the main side effect being hematologic depression. The results represent a 43-month trial of L-2 protocol. Conclusion as to the eventual duration of remissions awaits longer followup. Cancer 33:1490–1490, 1974.