2.1 Patients
Clinical data of pediatric AML patients enrolled in Children’s Oncology Group (COG) trials AAML0531 and AAML03P1 were extracted from the TARGET dataset (https://portal.gdc.cancer.gov). Cases diagnosed with acute promyelocytic leukemia, significant data missing, and age ≥21 years were excluded. A total of 713 cases were included in the present study after data filtering. The treatment protocols of the three clinical trials have been reported previously17,18. AAML0531 and AAML03P1 shared similar conventional chemotherapy dosages and durations. However, in the AAML03P1 trial, patients routinely underwent GO therapy during two cycles of chemotherapy, whereas in the AAML0531 trial, patients were subject to random allocation, determining their eligibility for the GO regimen. Lumbar puncture was carried out as a component of the diagnostic assessment. CNS disease was defined as the presence with any leukemic blasts in cerebrospinal fluid (CSF) without blood contamination, clinical manifestations of CNS leukemia, or radiographic evidence of intradural myeloid sarcoma. Myeloid sarcoma was confirmed by pathology and/or imaging.
In the AAML0531 and AAML03P1 trials, CNS prophylaxis involved administering intrathecal (IT) cytarabine on the first day of induction I/II and intensification I/II or biweekly, with a maximum of six doses. Patients with CNS involvement received IT cytarabine biweekly until the CSF was transparent and two additional IT cytarabine treatments. Patients were excluded from the trials when CNS leukemia still persisted after receiving six doses of IT cytarabine.