Clinicopathologic characteristics of leukemia in Japanese children and young adults

Abstract

The aim of this study is to clarify the clinicopathologic characteristics of adolescent leukemia in Japan by retrospective analysis. Patients with acute lymphoblastic leukemia (ALL), acute myelogenous leukemia (AML), chronic myelogenous leukemia (CML), and myelodysplastic syndrome (MDS), consecutively diagnosed from 1986 to 1999, were enrolled. A total of 3856 patients from 1 to 15 years of age and 1803 patients from 15 to 29 years of age were eligible for this study. Demographically, the frequency of AML found was almost constant during the teenage years, whereas the frequency of ALL gradually decreased. The relative frequency of CML and MDS apparently started to increase in patients in their late teens. The relative frequency of M3 and t(15;17) gradually increased during adolescence. Among patients aged 1 to 4 years, M7 was the most frequent FAB subtype. Among patients aged 5 to 9 years, M2 and t(8;21) was the most frequent subtype. The percentage of T cell ALL increased in patients 5 to 9 years old, reaching 31.2% in the 20-to 24-year-old age group. The percentage of patients with hyperdiploidy over 50 chromosomes was highest (17.0%) in patients aged 1 to 4 and decreased to 3.9% in the older teens. The percentage of patients with the Ph 1 chromosome increased from 9.9% in teens to 30.0% in patients in their late twenties. When comparing event-free survival (EFS) rates for ALL according to age, the estimated 7-year EFS rate was highest for patients aged 1 to 9 years (65.9%) and intermediate for patients aged 10 to 15 years (48.4%). However, the EFS rate was significantly worse for patients aged 15 to 19 years (19.4%) and 20 to 29 years (17.0%) (P = 0.024). On the other hand, the EFS rate for AML decreased with increasing age, although without statistical significance. The overall survival rates are approximate among all age groups. The results of the study indicate that there are considerable variations in biologic features of leukemia between children and young adults. The prognosis for adolescent leukemia may be improved by introducing pediatric trials, which take into account the prognostic biological features. Leukemia (2001Leukemia ( ) 15, 1256Leukemia ( -1261

Age Difference in Immunophenotype of Acute Leukemia

“…In consistent with other reports [14,21,22] , the frequency of B-cell ALL was less common in the child group (2 of 300 cases, 0.7%) and that of T-cell ALL was more prominent in the adult group (19 of 104 cases, 18.3%) than in any other age groups, respectively. CD10+ precursor B-cell ALL was more common in the child group (252 of 300 cases, 84%) than in the adult group (70 of 104 cases, 67.3%, p<.01).…”

“…It is possible that the adult group represent a relatively low percentage of such leukemia in comparison with the other age groups due to the high frequency of T-cell ALL. Regarding the karyotype, the incidence of Ph significantly rose with increasing patient age, as previously described 22 . In similar to other reports [5,23] , the expression rate of 11q23 tended to decrease with patient age.…”

Acute leukemias in Piauí: comparison with features observed in other regions of Brazil

“…A peak of incidence between 2-10 years was found, as observed in most studies around the world but not in Africa (23). This pattern of incidence has been well established but has only recently emerged among African American and Japanese children (1,4). Only few cases were older than 30 years, in contrast to the United States and Europe, where a small peak of incidence emerges above 50 years (1,5).…”

Allogeneic bone marrow transplantation for chronic myeloid leukemia in childhood: a report from the Société Française de Greffe de Moelle et de Thérapie Cellulaire (SFGM-TC)

“…13 Series including exclusively pediatric patients transplanted for CML are very rare and concern cohorts of a limited number of patients. [6][7][8] The present study of a large cohort of children and teenagers with CML indicates that HSC transplantation results in long-term survival in more than half of the patients with an MSD.…”