Veerman, A. et al. Dexamethasone-based therapy for childhood acute lymphoblastic leukaemia: results of the prospective Dutch Childhood Oncology Group (DCOG) protocol ALL-9 (1997-2004). Lancet Oncol. 10, 957–966 (2009).

Many children with acute lymphoblastic leukemia (ALL) are cured with current therapies; however, overtreatment results in exopsure to unnecessary adverse effects. The Dutch Childhood Leukemia Study Group protocol ALL-6 is the most-effective treatment for non-high-risk patients to date; the ALL-9 protocol is identical to ALL-6 but includes a higher methotrexate dose and two intensifications stages. Veerman and colleagues carried out a study to confirm the results of the ALL-6 protocol in high-risk patients and compare the results with ALL-7 and ALL-8.

In this non-randomized prospective study, a dexamethsone-based protocol (ALL-9) was used to treat 859 children aged 1–18 years with ALL. Patients were divided into high-risk (n = 258) and non-high-risk groups (n = 601). The non-high-risk patients were treated with induction therapy for 6 weeks, medium-dose methotrexate for 3 weeks and then maintenance therapy. The high-risk patients received the same induction therapy plus daunorubicin for 6 weeks, high-dose methotrexate for 8 weeks, and two intensification courses before receiving maintenance therapy.

Complete remission was achieved by 98.5% of patients in the non-high-risk group and 96.9% in the high-risk group. The 5-year event-free survival was higher in the non-high-risk patients than the high-risk patients (84% versus 72%).

The authors conclude that the results of the ALL-9 protocol are better than previous protocols.