title: 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.
abstract: 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.
authors.affiliation: Third Department of Internal Medicine, Kyoto Prefectural University of Medicine, Japan.
authors.forename: Tomomi
authors.initials: T
authors.lastname: Okamoto
authors.forename: Shouhei
authors.initials: S
authors.lastname: Yokota
authors.forename: Naoyuki
authors.initials: N
authors.lastname: Katano
authors.forename: Taku
authors.initials: T
authors.lastname: Seriu
authors.forename: Makoto
authors.initials: M
authors.lastname: Nakao
authors.forename: Masafumi
authors.initials: M
authors.lastname: Taniwaki
authors.forename: Arata
authors.initials: A
authors.lastname: Watanabe
authors.forename: Keiko
authors.initials: K
authors.lastname: Asami
authors.forename: Atsushi
authors.initials: A
authors.lastname: Kikuta
authors.forename: Shoichi
authors.initials: S
authors.lastname: Koizumi
authors.forename: Tetsuo
authors.initials: T
authors.lastname: Kawakami
authors.forename: Shigeru
authors.initials: S
authors.lastname: Ohta
authors.forename: Munenori
authors.initials: M
authors.lastname: Miyake
authors.forename: Tsutomu
authors.initials: T
authors.lastname: Watanabe
authors.forename: Asayuki
authors.initials: A
authors.lastname: Iwai
authors.forename: Akira
authors.initials: A
authors.lastname: Kamitamari
authors.forename: Osamu
authors.initials: O
authors.lastname: Ijichi
authors.forename: Nobuyuki
authors.initials: N
authors.lastname: Hyakuna
authors.forename: Junichi
authors.initials: J
authors.lastname: Mimaya
authors.forename: Takeo
authors.initials: T
authors.lastname: Fujimoto
authors.forename: Masahito
authors.initials: M
authors.lastname: Tsurusawa
mesh_terms: 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