Minimal residual disease in early phase of chemotherapy reflects poor outcome in children with acute lymphoblastic leukemia--a retrospective study by the Children's Cancer and Leukemia Study Group in Japan.
We analyzed the minimal residual disease (MRD) in 50 children with acute lymphoblastic leukemia (ALL) by amplifying the clonally rearranged T-cell receptor (TCR) gamma/delta chain and/or immunoglobulin (Ig) kappa chain gene using the allele-specific-PCR method. All children were treated according to the protocols of the Children's Cancer and Leukemia Study Group of Japan (CCLSG). The patients were stratified into four risk-groups according to the leukocyte count and age at diagnosis. We prospectively sampled the patients' bone marrow at 1 month (point 1) and 3 months (point 2) after the initiation of chemotherapy and quantitated the MRD retrospectively. The results of MRD were closely related with the clinical outcome. The relapse rate of the patients MRD-positive at points 1 and 2 was 46% (6/13) and 86% (6/7), respectively, whereas those MRD-negative results at point 1 and 2 were 13% (3/13) and 3% (3/30), respectively. We found significant differences in the event-free survival between MRD-positive children and MRD-negative children like the reports, which have been made by BFM and EORTC groups. We conclude that MRD in an early phase of chemotherapy can be a good predictor of the prognosis of childhood ALL regardless of the protocol of chemotherapy or race.
Okamoto
Tomomi
T
Third Department of Internal Medicine, Kyoto Prefectural University of Medicine, Japan.
Yokota
Shouhei
S
Katano
Naoyuki
N
Seriu
Taku
T
Nakao
Makoto
M
Taniwaki
Masafumi
M
Watanabe
Arata
A
Asami
Keiko
K
Kikuta
Atsushi
A
Koizumi
Shoichi
S
Kawakami
Tetsuo
T
Ohta
Shigeru
S
Miyake
Munenori
M
Watanabe
Tsutomu
T
Iwai
Asayuki
A
Kamitamari
Akira
A
Ijichi
Osamu
O
Hyakuna
Nobuyuki
N
Mimaya
Junichi
J
Fujimoto
Takeo
T
Tsurusawa
Masahito
M
D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D005260:Female; D015321:Gene Rearrangement; D015329:Gene Rearrangement, T-Lymphocyte; D005803:Genes, Immunoglobulin; D006801:Humans; D007223:Infant; D008297:Male; D018365:Neoplasm, Residual; D054198:Precursor Cell Lymphoblastic Leukemia-Lymphoma / Q000188:drug therapy* / Q000276:immunology / Q000401:mortality; D012189:Retrospective Studies