2.1 Patients and treatment
A total of 176 pediatric patients with Ph-negative BCP-ALL were enrolled
in the current study. They were diagnosed at our hospital from December
2008 to January 2016, received at least 1 course of chemotherapy and
received chemotherapy only as post-remission treatment. The median age
at diagnosis was 4 (range, 0-16) years. A total of 94 (53.4%) patients
were male. The diagnosis was based on bone marrow morphology,
immunophenotyping, karyotyping and molecular testing. The cutoff date
for follow-up was December 2019.
As we reported previously,19,20 all the patients
received treatments according to an improved
ALL-Berlin-Frankfurt-Munster (BFM) protocol or the Chinese Children’s
Protocol for ALL 2008 (CCLG-ALL-2008). Briefly, the CODPL
(cyclophosphamide and prednisone or dexamethasone, vincristine, and
daunorubicin or idarubicin and L-asparaginase) regimen was used during
induction therapy; 15 courses of high-dose methotrexate with or without
pegaspargase, 3 courses of high-dose cytarabine, and a round of
ifosfamide were used during consolidation therapy. Re-induction therapy
was administered at half-year intervals during consolidation therapy.
The cumulative doses of L-asparaginase and daunorubicin (or idarubicin)
were 300,000 units/m2 and 400(or 100)
mg/m2, respectively. 6-mercaptopurine and methotrexate
were used for maintenance therapy. Besides, 23-25 doses of intrathecal
methotrexate, cytarabine, and dexamethasone administration was used for
central nervous system leukemia (CNSL) prevention. The whole treatment
course lasted 3-3.5 years.
The study was approved by the Ethics Committee of Peking University
People’s Hospital, and all of the patients’ parents/guardians provided
written informed consent to participate in the study in accordance with
the Declaration of Helsinki.