Clinical significance of minimal residual disease in childhood acute lymphoblastic leukemia after first relapse.
Using flow cytometric techniques capable of detecting 0.01% leukemic cells, we prospectively studied minimal residual disease (MRD) in patients with acute lymphoblastic leukemia (ALL) after first relapse. At the end of remission reinduction, 41 patients had a bone marrow sample adequate for MRD studies; 35 of these were in morphologic remission. Of the 35 patients, 19 (54%) had MRD >/=0.01%, a finding that was associated with subsequent leukemia relapse. The 2-year cumulative incidence of second leukemia relapse was 70.2+/-12.3% for the 19 MRD-positive patients and 27.9+/-12.4% for the 16 MRD-negative patients (P=0.008). Among patients with a first relapse off therapy, 2-year second relapse rates were 49.1+/-17.8% in the 12 MRD-positive and 0% in the 11 MRD-negative patients (P=0.014); among those who received only chemotherapy after first relapse, the 2-year second relapse rates were 81.5+/-14.4% (n=12) and 25.0+/-13.1% (n=13), respectively (P=0.004). Time of first relapse and MRD were the only two significant predictors of outcome in a multivariate analysis. We conclude that MRD assays should be used to guide the selection of postremission therapy in patients with ALL in first relapse.
Coustan-Smith
E
E
Department of Hematology-Oncology, Children's Research Hospital, Memphis, TN, USA.
Gajjar
A
A
Hijiya
N
N
Razzouk
B I
BI
Ribeiro
R C
RC
Rivera
G K
GK
Rubnitz
J E
JE
Sandlund
J T
JT
Andreansky
M
M
Hancock
M L
ML
Pui
C-H
CH
Campana
D
D
D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use; D001853:Bone Marrow / Q000473:pathology; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D009364:Neoplasm Recurrence, Local / Q000188:drug therapy / Q000473:pathology*; D018365:Neoplasm, Residual / Q000188:drug therapy / Q000473:pathology*; D054198:Precursor Cell Lymphoblastic Leukemia-Lymphoma / Q000188:drug therapy / Q000473:pathology*; D011379:Prognosis; D011446:Prospective Studies; D012074:Remission Induction