[Long-term follow-up of treatment outcome and prognosis on 46 children with acute promyelocytic leukemia].
OBJECTIVE
Acute promyelocytic leukemia (APL) is a specific type of hematopoietic malignancy, accounting for 10% of the de novo acute myeloid leukemia (AML). The data on long-term outcome of APL in children are limited. The aim of this study was to investigate the clinical biological features, diagnosis, prognosis and long-term survival of childhood APL.


METHODS
A total of 46 children with newly diagnosed APL from April 1998 to October 2005 were enrolled into this study. Induction treatment containing all-trans retinoic acid (ATRA) plus daunorubicin (DNR) or pirarubicin (THP) was performed on these patients, followed by 6 courses of chemotherapy consolidation: DNR, homoharringtonine or etoposide plus Ara-C. A maintenance therapy was then administered once 3-6 months. The total period of treatment was 2.5 years.


RESULTS
Of the 39 patients who had completed the regular treatment, 36 (92.3%) achieved a complete remission. The 5-year cumulative incidence of relapse (CIR) was 28.6%. The estimated overall survival (OS) rates at 1, 3 and 5 years were (86.1 +/- 5.8)%, (76.1 +/- 7.5)% and (70.2 +/- 8.9)% respectively, while the event free survival (EFS) rates were (78.4 +/- 6.8)%, (63.6 +/- 8.7)% and (53.1 +/- 10.0)% respectively. The 5-year OS rate of patients with WBC less than or equal to 10.0 X 10(9)/L was (81.4 +/- 10.3)%, which was significantly higher than that with WBC greater than 10.0 X 10(9)/L[(51.6 +/- 14.7)%, P < 0.05]. Five patients with RT-PCR positive for PML/RARalpha S (short) subtype died eventually although all of them achieved CR, but none of the 13 patients with PML/RARalpha L (long) subtype died.


CONCLUSIONS
Remission induction therapy with ATRA + DNR or THP is effective and safe for newly diagnosed childhood APL. The remission induction therapy combined with chemotherapy containing high/intermediate dose Ara-C can improve the long-term survival rates of APL patients. High WBC count and S subtype of PML-RARa are two poor prognostic factors for children with APL.
Xu
Xiao-Jun
XJ
Department of Hematology/Oncology, Children's Hospital of Zhejiang University School of Medicine, Hangzhou 310003, China.
Shi
Shu-Wen
SW
Tang
Yong-Min
YM
Song
Hua
H
Yang
Shi-Long
SL
Wei
Jian
J
Xu
Wei-Qun
WQ
Pan
Bin-Hua
BH
Chen
Ying-Hu
YH
Zhao
Fen-Ying
FY
Shen
Hong-Qiang
HQ
Qian
Bai-Qin
BQ
Zhang
Ling-Yan
LY
Ning
Bo-Tao
BT
D000293:Adolescent; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use; D002648:Child; D002675:Child, Preschool; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007223:Infant; D015473:Leukemia, Promyelocytic, Acute / Q000188:drug therapy* / Q000401:mortality; D008297:Male; D015514:Oncogene Proteins, Fusion / Q000235:genetics; D011379:Prognosis; D015996:Survival Rate; D016896:Treatment Outcome; D014212:Tretinoin / Q000008:administration & dosage
D015514:Oncogene Proteins, Fusion; C093476:promyelocytic leukemia-retinoic acid receptor alpha fusion oncoprotein; D014212:Tretinoin