title: Incidence and clinical relevance of abnormal complete blood counts in long-term survivors of childhood cancer.
abstract: BACKGROUND
  The purpose of the study was to determine the incidence and clinical significance of abnormal complete blood counts (CBCs) obtained during follow-up of childhood cancer survivors.
  
  
  METHODS
  A retrospective cohort study was conducted on 193 survivors, diagnosed between 1970-1986, who were followed in our center's After Cancer Experience Program and are participants in the Childhood Cancer Survivor Study. Of these patients, 49% were female and 25% were racial/ethnic minorities. The primary outcome was determination of the cumulative percentage of patients having an abnormal CBC by 2 or 3 standard deviations (SDs). Four components of the CBC were examined and employed to define an abnormal CBC: low white blood cell count (WBC), high mean corpuscular volume (MCV), low platelet count, and low hemoglobin concentration. Association of treatment exposures to abnormal values was assessed with a multilevel logistic model.
  
  
  RESULTS
  There were 1297 patient visits during 1401 person-years of follow-up. The mean number of visits per survivor was 6.7 (SD 4.2). The cumulative percentage of subjects with at least one abnormal CBC was 70%. The cumulative percent of subjects with a value abnormal by 2 SD was WBC = 23%, MCV = 37%, platelets = 9%, hemoglobin = 49%. For values abnormal by 3 SD, the frequencies were WBC = 3%, MCV = 20%, platelets = 1%, hemoglobin = 27%. None of the patients developed myelodysplastic syndrome or a secondary leukemia during the follow-up period. Exposure to epipodophyllotoxins was associated with an increased risk of having abnormally high MCV values.
  
  
  CONCLUSIONS
  Mildly abnormal CBC values are common in survivors of childhood cancer. Abnormal values are often of questionable significance but seem to persist over time. Epipodophyllotoxin therapy was found to be associated with increased frequency of high MCV levels.
authors.affiliation: Department of Family Practice & Community Medicine, University of Texas Southwestern Medical Center, Dallas, USA.
authors.forename: Zsofia B
authors.initials: ZB
authors.lastname: Long
authors.forename: Kevin C
authors.initials: KC
authors.lastname: Oeffinger
authors.forename: Sandra L
authors.initials: SL
authors.lastname: Brooks
authors.forename: Lori
authors.initials: L
authors.lastname: Fischbach
authors.forename: T Robert
authors.initials: TR
authors.lastname: Harris
authors.forename: Debra A
authors.initials: DA
authors.lastname: Eshelman
authors.forename: Gail E
authors.initials: GE
authors.lastname: Tomlinson
authors.forename: George R
authors.initials: GR
authors.lastname: Buchanan
mesh_terms: D000293:Adolescent; D000972:Antineoplastic Agents, Phytogenic / Q000009:adverse effects / Q000627:therapeutic use; D001772:Blood Cell Count; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D005260:Female; D005500:Follow-Up Studies; D006402:Hematologic Diseases / Q000453:epidemiology / Q000209:etiology*; D006801:Humans; D015994:Incidence; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D009369:Neoplasms / Q000097:blood*; D011034:Podophyllotoxin / Q000009:adverse effects / Q000627:therapeutic use; D011379:Prognosis; D017741:Survivors
chemical_list: D000972:Antineoplastic Agents, Phytogenic; D011034:Podophyllotoxin