title: Usefulness and limits of CA-125 in diagnosis of endometriosis without associated ovarian endometriomas.
abstract: BACKGROUND
  The aim of this study was to evaluate the diagnostic significance of CA-125 for endometriosis without ovarian endometriomas.
  
  
  METHODS
  Preoperative serum CA-125 levels were measured in 775 consecutive women diagnosed by laparoscopy or laparotomy with endometriosis, adenomyosis, leiomyomas, or normal pelvis.
  
  
  RESULTS
  Receiver operating characteristic curve analysis revealed that the area under the curve for endometriosis without endometriomas was 0.788, significantly smaller than that for endometriosis with endometriomas (0.935, P < 0.05). In diagnosis of endometriosis without endometriomas, both the maximal accuracy of 78.8% and the maximal diagnostic value of 61.2% were obtained at the cutoff value of 20 U/mL. Negative predictive value was 78.0% at the cutoff value of 20 U/mL, whereas positive predictive value was 92.9% at the cutoff value of 30 U/mL. This range is clearly superior to the empirical single cutoff of 35 U/mL.
  
  
  CONCLUSIONS
  In the diagnosis of endometriosis without endometriomas, combined use of two cutoff values for CA-125, 20 and 30 U/mL, provides improved diagnostic performance. However, the accuracy of using only CA-125 testing for diagnosis is still limited. Serum CA-125 testing can be done during initial screenings of women with possible endometriosis.
authors.affiliation: Department of Obstetrics and Gynecology, Kyoto Prefectural University of Medicine, Graduate School of Medical Science, Kyoto 602-8566, Japan. kitawaki@koto.kpu-m.ac.jp
authors.forename: Jo
authors.initials: J
authors.lastname: Kitawaki
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Ishihara
authors.forename: Hisato
authors.initials: H
authors.lastname: Koshiba
authors.forename: Miyo
authors.initials: M
authors.lastname: Kiyomizu
authors.forename: Mariko
authors.initials: M
authors.lastname: Teramoto
authors.forename: Yui
authors.initials: Y
authors.lastname: Kitaoka
authors.forename: Hideo
authors.initials: H
authors.lastname: Honjo
mesh_terms: D000328:Adult; D018394:CA-125 Antigen / Q000097:blood*; D016022:Case-Control Studies; D004715:Endometriosis / Q000175:diagnosis* / Q000276:immunology*; D005260:Female; D006801:Humans; D010535:Laparoscopy; D007813:Laparotomy; D007889:Leiomyoma / Q000175:diagnosis / Q000276:immunology; D010049:Ovarian Diseases / Q000175:diagnosis / Q000276:immunology; D014594:Uterine Neoplasms / Q000175:diagnosis / Q000276:immunology
chemical_list: D018394:CA-125 Antigen