title: High-risk childhood acute lymphoblastic leukemia in China: factors influencing the treatment and outcome.
abstract: OBJECTIVE
  Acute lymphoblastic leukemia (ALL) with high-risk features has an inferior outcome. Factors influencing the treatment and outcome of pediatric ALL with high-risk features in developing countries have not been well studied.
  
  
  METHODS
  High-risk features were defined as: age <1 year or >10 years, white blood cell (WBC) > 50 x 10(9)/L, CNS or testicular involvement at diagnosis, T-ALL, BCR-ABL/MLL-AF4, poor prednisone response, slow early response to induction chemotherapy which was defined as M3 status (>25% blasts) on day 15 bone marrow with age >6 years or presenting WBC > 20 x 10(9)/L at diagnosis and/or non-remission (NR) after 33 days of induction therapy.
  
  
  RESULTS
  Ninety-one children were analyzed. The total rate of treatment abandonment was 24.2% and treatment-related mortality was 3.3% (3/91). The event-free survival (EFS) was 52.3% (95% CI, 41.5-63.1%) at 4 years and 49.9% (95% CI, 38.9-60.9%) at 8 years, respectively. When the cases who abandoned treatment were excluded, the EFS of the remainder was 68.3% (95% CI, 56.5-80.1%) at 4 years and 65.2% (95% CI, 52.5-77.9%) at 8 years, respectively. NR on day 33 or BCR-ABL remained as an independent unfavorable prognostic factor in the Cox model even if more intense chemotherapy was administrated.
  
  
  CONCLUSIONS
  A decreased treatment-related death frequency was associated with an improved outcome of leukemia. This emphasizes the importance of improving supportive care in developing countries for children with high-risk ALL who receive very intensive chemotherapy. Treatment abandonment remains a prominent reason for treatment failure in China.
authors.affiliation: Department of Pediatrics, The First Affiliated Hospital of Sun Yat-Sen University, Zhongshan Er Lu, Guangzhou, China. l-xuequn@126.com
authors.forename: Xue-Qun
authors.initials: XQ
authors.lastname: Luo
authors.forename: Zhi-Yong
authors.initials: ZY
authors.lastname: Ke
authors.forename: Li-Bin
authors.initials: LB
authors.lastname: Huang
authors.forename: Xiao-Qing
authors.initials: XQ
authors.lastname: Guan
authors.forename: Ying-Chuan
authors.initials: YC
authors.lastname: Zhang
authors.forename: Xiao-Li
authors.initials: XL
authors.lastname: Zhang
mesh_terms: D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D002681:China / Q000453:epidemiology; D003906:Developing Countries; D005260:Female; D006801:Humans; D008297:Male; D054198:Precursor Cell Lymphoblastic Leukemia-Lymphoma / Q000175:diagnosis / Q000188:drug therapy / Q000453:epidemiology* / Q000401:mortality; D011379:Prognosis; D011446:Prospective Studies; D012307:Risk Factors; D016019:Survival Analysis; D016896:Treatment Outcome