Outcomes of Children with Acute Lymphoblastic Leukemia Treated with 2 Consecutive Protocols: Ramathibodi Hospital Experience

We determined the outcomes and prognostic factors of children (age, 0.8 to 14.8 years) with acute lymphoblastic leukemia (ALL) treated with 2 consecutive protocols between 1997 and 2008. The risk classification was followed NCI criteria. One hundred and one patients, (60 males and 41 females), were enrolled to the first protocol (modified St Jude Total XIII) (1997–2003). Ninety seven patients (96%) of these 101 patients achieved remission after induction. The event free survival (EFS) rates were 90.1 ± 3%, 85 ± 3.6%, and 83.8 ± 3.7%, and the cumulative risk of CNS relapse were 2.1 ± 1.5%, 3.2 ± 1.8%, and 3.2 ± 1.8%, at 3, 5, and 10 years, respectively. The median follow-up time for patients remaining free of adverse events was 6.8 years (4.2–10.3 years). The adverse prognostic factors included obesity (p =0.013), high risk group (p= 0.012), minimal residual leukemia (MRD) presence (> 0.01%) on day 15 of induction (p <0.001) and sepsis during treatment (p= 0.003). For the second protocol (modified St Jude Total XV) (2004–2008), 80 patients, 43 males and 37 females, were enrolled. Seventy nine (98.8%) of these 80 patients achieved remission after induction. The EFS rates were 92.1 ± 3.1% and 88.9 ± 3.7% at 1 and 3 years, respectively. The median follow-up time was 2.6 years (0.1–4.3 years) without evidence of CNS relapse. The adverse prognostic factor included mucositis during treatmenrt (p = 0.014). The EFS rates up to 85% in childhood ALL treated with two consecutive protocols attest the effectiveness of risk-adaptive therapy and multidisciplinary approach. Regarding to the second protocol, the efficacy of intensive systemic and intrathecal chemotherapy further supports the probability of eliminating cranial radiation and early therapeutic intervention on patients with persistent MRD leading to improve outcome overall, irrespective of patient’s risk groups. Further studies on pharmacogenetic, genetic and proteomic profiles of leukemic cells ascertain the precise risk classification and treatment regimen of childhood ALL in the future.