Improved risk classification for risk-specific therapy based on the molecular study of minimal residual disease (MRD) in adult acute lymphoblastic leukemia (ALL).
Clinical risk classification is inaccurate in predicting relapse in adult patients with acute lymphoblastic leukemia, sometimes resulting in patients receiving inappropriate chemotherapy or stem cell transplantation (SCT). We studied minimal residual disease (MRD) as a predictive factor for recurrence and as a decisional tool for postconsolidation maintenance (in MRD(neg)) or SCT (in MRD(pos)). MRD was tested at weeks 10, 16, and 22 using real-time quantitative polymerase chain reaction with 1 or more sensitive probes. Only patients with t(9;22) or t(4;11) were immediately eligible for allogeneic SCT. Of 280 registered patients (236 in remission), 34 underwent an early SCT, 60 suffered from relapse or severe toxicity, and 142 were evaluable for MRD at the end of consolidation. Of these, 58 were MRD(neg), 54 MRD(pos), and 30 were not assessable. Five-year overall survival/disease-free survival rates were 0.75/0.72 in the MRD(neg) group compared with 0.33/0.14 in MRD(pos) (P = .001), regardless of the clinical risk class. MRD was the most significant risk factor for relapse (hazard ratio, 5.22). MRD results at weeks 16 to 22 correlated strongly with the earlier time point (P = .001) using a level of 10(-4) or higher to define persistent disease. MRD analysis during early postremission therapy improves risk definitions and bolsters risk-oriented strategies. ClinicalTrials.gov identifier: NCT00358072.
Bassan
Renato
R
Unità Strutturale Complessa di Ematologia, Ospedali Riuniti, Bergamo, Italy. rbassan@ospedaliriuniti.bergamo.it
Spinelli
Orietta
O
Oldani
Elena
E
Intermesoli
Tamara
T
Tosi
Manuela
M
Peruta
Barbara
B
Rossi
Giuseppe
G
Borlenghi
Erika
E
Pogliani
Enrico M
EM
Terruzzi
Elisabetta
E
Fabris
Pietro
P
Cassibba
Vincenzo
V
Lambertenghi-Deliliers
Giorgio
G
Cortelezzi
Agostino
A
Bosi
Alberto
A
Gianfaldoni
Giacomo
G
Ciceri
Fabio
F
Bernardi
Massimo
M
Gallamini
Andrea
A
Mattei
Daniele
D
Di Bona
Eros
E
Romani
Claudio
C
Scattolin
Anna Maria
AM
Barbui
Tiziano
T
Rambaldi
Alessandro
A
D000293:Adolescent; D000328:Adult; D000368:Aged; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use; D003131:Combined Modality Therapy; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D018365:Neoplasm, Residual / Q000235:genetics*; D015514:Oncogene Proteins, Fusion / Q000235:genetics; D054198:Precursor Cell Lymphoblastic Leukemia-Lymphoma / Q000145:classification* / Q000401:mortality / Q000628:therapy*; D011379:Prognosis; D011446:Prospective Studies; D012307:Risk Factors; D033581:Stem Cell Transplantation; D015996:Survival Rate; D014178:Translocation, Genetic; D019172:Transplantation Conditioning; D014184:Transplantation, Homologous; D016896:Treatment Outcome; D055815:Young Adult
D015514:Oncogene Proteins, Fusion