Outcome of patients treated for relapsed or refractory acute lymphoblastic leukemia: a Therapeutic Advances in Childhood Leukemia Consortium study.
OBJECTIVE
Despite improvements in treatment, approximately 20% of patients with acute lymphoblastic leukemia (ALL) experience relapse and do poorly. The Therapeutic Advances in Childhood Leukemia (TACL) Consortium was assembled to assess novel drugs for children with resistant leukemia. We hypothesize that novel agents and combinations that fail to improve baseline complete remission rates in comparable populations are unlikely to contribute to better outcomes and should be abandoned. We sought to define response rates and disease-free survival (DFS) rates in patients treated at TACL institutions, which could serve as a comparator for future studies.


METHODS
We performed a retrospective cohort review of patients with relapsed and refractory ALL previously treated at TACL institutions between the years of 1995 and 2004. Data regarding initial and relapsed disease characteristics, disease response, and survival were collected and compared with those of published reports.


RESULTS
Complete remission (CR) rates (mean +/- SE) were 83% +/- 4% for early first marrow relapse, 93% +/- 3% for late first marrow relapse, 44% +/- 5% for second marrow relapse, and 27% +/- 6% for third marrow relapse. Five-year DFS rates in CR2 and CR3 were 27% +/- 4% and 15% +/- 7% respectively.


CONCLUSIONS
We generally confirm a 40% CR rate for second and subsequent relapse, but our remission rate for early first relapse seems better than that reported in the literature (83% v approximately 70%). Our data may allow useful modeling of an expected remission rate for any population of patients who experience relapse.
Therapeutic Advances in Childhood Leukemia Consortium, Institute for Pediatric Clinical Research and Childrens Center for Cancer and Blood Diseases, University of Southern California-Childrens Hospital Los Angeles, Los Angeles, CA, USA.
Richard H
RH
Ko
Lingyun
L
Ji
Phillip
P
Barnette
Bruce
B
Bostrom
Raymond
R
Hutchinson
Elizabeth
E
Raetz
Nita L
NL
Seibel
Clare J
CJ
Twist
Elena
E
Eckroth
Richard
R
Sposto
Paul S
PS
Gaynon
Mignon L
ML
Loh
D000293:Adolescent; D000328:Adult; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D003131:Combined Modality Therapy; D019008:Drug Resistance, Neoplasm; D005260:Female; D005500:Follow-Up Studies; D018380:Hematopoietic Stem Cell Transplantation; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D009364:Neoplasm Recurrence, Local / Q000401:mortality* / Q000473:pathology / Q000628:therapy*; D054198:Precursor Cell Lymphoblastic Leukemia-Lymphoma / Q000401:mortality* / Q000473:pathology / Q000628:therapy*; D011379:Prognosis; D012074:Remission Induction; D012189:Retrospective Studies; D016879:Salvage Therapy; D015996:Survival Rate; D016896:Treatment Outcome; D055815:Young Adult