title: The clinical significance of CD34 expression in response to therapy of patients with acute myeloid leukemia: an overview of 2483 patients from 22 studies.
abstract: BACKGROUND
  Although many studies have been performed to evaluate the prognostic significance of CD34 expression in acute myeloid leukemia (AML), the findings have been inconsistent. In this study, the authors reviewed such previous studies to establish a definite conclusion.
  
  
  METHODS
  Using MEDLINE, the authors identified studies that evaluated the prognostic significance of CD34 expression in AML. The outcome measure was the complete remission rate. They used the random-effect method to combine the results. Results were presented as odds ratios (ORs) with 95% confidence intervals (CIs). The ORs were less than 1 if the complete remission occurred more frequently in the CD34 negative group.
  
  
  RESULTS
  Twenty-two studies including 2483 patients were reviewed. The combined OR was 0.38 (95% CI, 0. 26-0.57), which suggested that CD34 expression was associated with a poor remission rate. However, the authors found statistical evidence of marked heterogeneity among trials (P < 0.001), especially according to time of publication. The combined OR in studies published in or after 1994 was 0.70 (95% CI, 0.47-1.09). The authors divided the studies into several subgroups, but they could not determine the reason for the heterogeneity.
  
  
  CONCLUSIONS
  At present, CD34 expression should not be considered a marker of poor prognosis because it is not supported by the combined data from recent studies. Further studies should be conducted to investigate the intensity of CD34 expression in specific populations of patients, such as those with t(8;21) or t(15;17) translocations or the AML-M0 subtype.
authors.affiliation: Department of Hematology, International Medical Center of Japan, Tokyo, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Kanda
authors.forename: T
authors.initials: T
authors.lastname: Hamaki
authors.forename: R
authors.initials: R
authors.lastname: Yamamoto
authors.forename: A
authors.initials: A
authors.lastname: Chizuka
authors.forename: M
authors.initials: M
authors.lastname: Suguro
authors.forename: T
authors.initials: T
authors.lastname: Matsuyama
authors.forename: N
authors.initials: N
authors.lastname: Takezako
authors.forename: A
authors.initials: A
authors.lastname: Miwa
authors.forename: M
authors.initials: M
authors.lastname: Kami
authors.forename: H
authors.initials: H
authors.lastname: Hirai
authors.forename: A
authors.initials: A
authors.lastname: Togawa
mesh_terms: D000208:Acute Disease; D018952:Antigens, CD34 / Q000378:metabolism*; D000951:Antigens, Neoplasm / Q000378:metabolism*; D016001:Confidence Intervals; D006801:Humans; D007938:Leukemia / Q000378:metabolism* / Q000401:mortality; D016017:Odds Ratio; D011379:Prognosis
chemical_list: D018952:Antigens, CD34; D000951:Antigens, Neoplasm