Treatment protocol
Patients were treated using modified BFM (Berlin-Frankfurt-Mṻnster) 95 protocol (Supporting information file). Children with ALL were divided into standard and high-risk (HR) groups. HR children were: age ≥10 years, total leukocyte counts (TLC) ≥50,000/cumm, T acute lymphoblastic leukemia (T ALL), mixed phenotype acute leukemia (MPAL), liver or spleen ≥5 cm below costal margin, t(9;22)(q31;q34.1) positive (BCR-ABL), other unfavorable cytogenetic abnormality, hypodiploidy (chromosome number ≤44), central nervous system (CNS) positive disease (blasts in cerebrospinal fluid at diagnosis or cranial nerve abnormality), or poor prednisolone response (absolute blast counts ≥1000/cumm on day 8 of prednisolone). All other children were classified as standard-risk (SR) children. All HR children except HR due to hepatosplenomegaly received prophylactic cranial radiation (CRT) of 12 Gy after Phase II B (reconsolidation). Children with CNS positive disease received 18 Gy CRT. Maintenance chemotherapy comprised of vincristine (1.5 mg/m2 every 4 weeks), prednisolone (60 mg/m2 for 7 days every 4 weeks), 6-mercaptopurine (6MP) (50 mg/m2 daily) and methotrexate (20 mg/m2 weekly) in both SR and HR groups. SR group also received intrathecal (IT) methotrexate every 8 weeks during maintenance chemotherapy.