Acute lymphoblastic leukemia in adolescents and young adults in Finland.
BACKGROUND
Interest has recently been paid to adolescents and young adults with acute lymphoblastic leukemia, particularly because all reports so far published indicate that these patients have a better outcome when treated with pediatric rather than adult therapeutic protocols. There are different biological subtypes of acute lymphoblastic leukemia with distinct features and prognoses; the distribution of these subtypes is not well known among adolescents. We, therefore, studied acute lymphoblastic leukemia in adolescents and young adults aged 10 to 25 years in Finland.


METHODS
This population-based study included 225 consecutive patients aged 10-25 years diagnosed with acute lymphoblastic leukemia during 1990-2004. One hundred and twenty-eight patients (10-16 years) were treated with pediatric Nordic (NOPHO) protocols, and 97 patients (17-25 years) with Finnish Leukemia Group National protocols. We characterized the biological subtypes, clinical features and outcome of these patients.


RESULTS
For the whole cohort, the remission rate was 96%, 5-year event-free survival 62% and overall survival 72%. The 5-year event-free survival was 67% for the pediatric treatment group and 60% for the adult treatment group (p=n.s.). Patients with inferior outcome were those with a white blood cell count >or= 100 x 10(9)/L, the Philadelphia chromosome and MLL. Good prognostic features were TEL-AML1, hyperdiploidy, and pediatric intermediate risk stratification.


CONCLUSIONS
Unlike all previous studies, we found that the outcome of adolescents and young adults with acute lymphoblastic leukemia treated with pediatric or adult therapeutic protocols was comparable. The success of the adult acute lymphoblastic leukemia therapy emphasizes the benefit of central referral of patients to academic centers and adherence to research protocols.
Usvasalo
Anu
A
Hospital for Children and Adolescents, University of Helsinki, P.O. Box 281, 00029 HUS, Helsinki, Finland. anu.usvasalo@helsinki.fi
Räty
Riikka
R
Knuutila
Sakari
S
Vettenranta
Kim
K
Harila-Saari
Arja
A
Jantunen
Esa
E
Kauppila
Marjut
M
Koistinen
Pirjo
P
Parto
Katriina
K
Riikonen
Pekka
P
Salmi
Toivo T
TT
Silvennoinen
Raija
R
Elonen
Erkki
E
Saarinen-Pihkala
Ulla M
UM
D000293:Adolescent; D000328:Adult; D000970:Antineoplastic Agents / Q000627:therapeutic use*; D001752:Blast Crisis; D002648:Child; D018572:Disease-Free Survival; D005260:Female; D005387:Finland; D006801:Humans; D015459:Leukemia-Lymphoma, Adult T-Cell / Q000188:drug therapy / Q000235:genetics / Q000401:mortality / Q000473:pathology; D007958:Leukocyte Count; D008297:Male; D010641:Phenotype; D010677:Philadelphia Chromosome; D054198:Precursor Cell Lymphoblastic Leukemia-Lymphoma / Q000188:drug therapy* / Q000235:genetics / Q000401:mortality / Q000473:pathology; D016019:Survival Analysis
D000970:Antineoplastic Agents