Risk classification at the time of diagnosis differentially affects the level of residual disease in children with B-precursor acute lymphoblastic leukemia after completion of therapy.
We have previously reported that children with B-precursor acute lymphoblastic leukemia (ALL) who remained in remission after successfully completing therapy had leukemia cells detectable by polymerase chain reaction (PCR) (N Engl J Med 1997;336(5):317-23). These patients were treated by an institutional protocol (P89-04) that lacked the post-remission intensification features of the contemporary Berlin-Frankfurt-Münster (BFM) based ALL protocols. In this report, we compared residual leukemia levels for patients on the P89-04 (n=15) and BFM-based Children's Cancer Group (CCG) studies (n=23) and for patients stratified according to risk group. Our goal was to establish which risk factors correlated with level of residual disease. Patients enrolled on the CCG protocols had lower levels of residual disease after completion of therapy than the P89-04 patients (P<0.019). Patients with high-risk disease also had lower levels of residual disease than patients with low risk disease (P<0.0001). Three-way analysis including time off treatment, risk group determined by features at presentation, and treatment protocol showed that risk group was the only significant independent variable (P<0.001).
Okcu
M Fatih
MF
Texas Children's Cancer Center, Baylor College of Medicine, 6621 Fannin, CC 1510.00, Houston, TX 77030-2399, USA. mfokcu@txccc.org
Roberts
W Mark
WM
Johnston
Dennis A
DA
Ouspenskaia
Maia V
MV
Papusha
Victor Z
VZ
Brandt
Mark A
MA
Zipf
Theodore F
TF
D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use*; D001856:Bone Marrow Examination; D005803:Genes, Immunoglobulin; D006801:Humans; D018365:Neoplasm, Residual / Q000175:diagnosis / Q000188:drug therapy / Q000209:etiology; D016133:Polymerase Chain Reaction; D015452:Precursor B-Cell Lymphoblastic Leukemia-Lymphoma / Q000175:diagnosis* / Q000188:drug therapy; D054198:Precursor Cell Lymphoblastic Leukemia-Lymphoma / Q000175:diagnosis* / Q000188:drug therapy; D012074:Remission Induction; D018570:Risk Assessment; D012307:Risk Factors; D013997:Time Factors