title: Diagnostic accuracy of preoperative alpha-fetoprotein as an ovarian tumor marker in children and adolescents: not as good as we thought?
abstract: OBJECTIVE
  To evaluate the diagnostic accuracy of preoperative serum alpha-fetoprotein (AFP) levels in predicting malignancy risk in children and adolescents presenting with ovarian neoplasms.
  
  
  METHODS
  In 110 girls aged 18 and below diagnosed with ovarian neoplasms, we retrospectively correlated preoperative serum AFP levels with histological diagnosis of germ cell tumor or immature teratoma (GCT/IT) versus non-GCT/IT, and benign versus non-benign. We determined area under receiver-operating characteristic curves (AUC), sensitivity, specificity, and likelihood ratios.
  
  
  RESULTS
  Twenty patients (18.2 %) had non-benign ovarian neoplasms, of which 12 had GCT/IT (10.9 %). In diagnosing GCT/IT versus non-GCT/IT, specificity of preoperative serum AFP was 87.8 %, sensitivity 66.7 %, and AUC 0.853. Excluding infants to remove the effects of increased variance in AFP in this group, specificity improved (92.0 %), but not sensitivity (66.7 %); AUC was 0.926. Increasing AFP cutoff to two times upper normal limit improved specificity (94.9 %), but not sensitivity (66.7 %). For benign versus non-benign tumors, AFP specificity was only 88.9 % and sensitivity 50.0 %.
  
  
  CONCLUSIONS
  The diagnostic accuracy of preoperative serum AFP for detecting GCT/IT in girls was limited by poor sensitivity and positive predictive value. Excluding infants and raising cutoff levels improved specificity marginally. Clinicians should be aware of these limitations when using AFP in the preoperative evaluation of childhood ovarian neoplasms.
authors: Department of Pediatric Surgery, KK Women's and Children's Hospital, 100 Bukit Timah Road, Singapore 229899, Singapore. amos.loh.hp@kkh.com.sg
authors: Amos Hong Pheng
authors: AH
authors: Loh
authors: Kelvin Wai Cheak
authors: KW
authors: Gee
authors: Joyce Horng Yiing
authors: JH
authors: Chua
mesh_terms: D000293:Adolescent; D000328:Adult; D014408:Biomarkers, Tumor / Q000097:blood; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D009373:Neoplasms, Germ Cell and Embryonal / Q000097:blood / Q000175:diagnosis*; D010051:Ovarian Neoplasms / Q000097:blood / Q000175:diagnosis*; D057234:Preoperative Period; D012372:ROC Curve; D015203:Reproducibility of Results; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D013724:Teratoma / Q000097:blood / Q000175:diagnosis*; D055815:Young Adult; D000509:alpha-Fetoproteins / Q000032:analysis*
chemical_list: D014408:Biomarkers, Tumor; D000509:alpha-Fetoproteins
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