Treatment
Patients were uniformly treated on a modified protocol based on the
ALL-MB 91 protocol, as detailed in table 1. This protocol was developed
by professor Günther Henze for the treatment of patients in Russia at a
time when less than 10 percent of children with ALL were surviving with
the aim to reduce toxicity in consolidation treatment and costs, without
affecting overall survival (OS) 7. Compared to the BFM
protocol that was broadly used in Europe, the dose of anthracyclines was
reduced in induction and in consolidation. In consolidation Capizzi
methotrexate courses were introduced to replace the high-dose
methotrexate elements of the BFM protocol. Furthermore, preventive
radiation of the central nervous system (CNS) was only performed in
high-risk patients. Instead, triple intrathecal chemotherapy with
methotrexate, cytarabine and prednisone was administered. The main
difference of the protocol used in Cambodia was the suppression of
cranial radiation therapy. Also, a cumulative dose of daunorubicin of
120 mg/m2 was given to patients with standard risk
(SR, see below) which was more than the SR arm of the ALL-MB-91 protocol
(45 mg/m2, only one dose during induction), but a
reduction of half of the cumulative dose compared to the standard BFM
protocol 7. Compared to current ALL protocols, this
regimen did neither include cyclophosphamide nor cytarabine and used
non-pegylated asparaginase to reduce costs.