Childhood Acute Lymphoblastic Leukemia Treatment (PDQ®): Treatment - Health Professional Information [NCI] - Postinduction Treatment for Specific ALL Subgroups
In addition to more frequent adverse prognostic factors, patients in this age group have higher rates of treatment-related mortality [24,25,26] and non-adherence to therapy.[26,27]
Studies from the United States and France were among the first to identify the difference in outcome based on treatment regimens. Other studies have confirmed that older adolescent and young adult patients fare better on pediatric rather than adult regimens.[28,29,30,31,32]; [Level of evidence: 2A] These study results are summarized in Table 3.
Given the relatively favorable outcome that can be obtained in these patients with chemotherapy regimens used for high-risk pediatric ALL, there is no role for the routine use of allogeneic HSCT for adolescents and young adults with ALL in first remission.
Evidence (pediatric treatment regimen):
- Investigators reported on 197 patients aged 16 to 21 years treated on the CCG study (a pediatric ALL regimen) who showed a 7-year EFS of 63% compared with 124 adolescents and young adults treated on the Cancer and Leukemia Group B (CALGB) study (an adult ALL regimen) with a 7-year EFS of 34%.
- A study from France of patients aged 15 to 20 years and diagnosed between 1993 and 1999 demonstrated superior outcome for patients treated on a pediatric trial (67%; 5-year EFS) compared with patients treated on an adult trial (41%; 5-year EFS).
- In the COG high-risk study (CCG-1961), the 5-year EFS rate for 262 patients aged 16 to 21 years was 71.5%.[Level of evidence: 1iiDi] For rapid responders randomly assigned to early intensive postinduction therapy on the augmented intensity arms of this study, the 5-year EFS rate was 82% (n = 88).
- The DFCI ALL Consortium reported that a study of 51 adolescents aged 15 to 18 years in a pediatric trial had a 5-year EFS of 78%.
- In an SJCRH study, 44 adolescents aged 15 to 18 years had an EFS of approximately 85% ± 5%.
- In a Spanish study, 35 adolescents (aged 15–18 years) and 46 young adults (aged 19–30 years) with standard-risk ALL were treated with a pediatric-based regimen.[Level of evidence: 2A]
- EFS rate was 61%.
- The OS rate was 69%.
- There were no differences in outcome between adolescents and young adults.
Other studies have confirmed that older adolescent patients and young adults fare better on pediatric rather than adult regimens (see Table 3).[29,31]; [Level of evidence: 2A]
The reason that adolescents and young adults achieve superior outcomes with pediatric regimens is not known, although possible explanations include the following: 
- Treatment setting (i.e., site experience in treating ALL).
- Adherence to protocol therapy.
- The components of protocol therapy.