title: Influence of CA 15-3 blood level and doubling time on diagnostic performances of 18F-FDG PET in breast cancer patients with occult recurrence.
abstract: OBJECTIVE
  To evaluate the influence of CA 15-3 blood level and doubling time on diagnostic performances of 18F-FDG PET in breast cancer patients with occult recurrence.
  
  
  METHODS
  Thirty-five 18F-FDG PET examinations in 32 patients with CA 15-3 blood level above the normal range, and negative conventional imaging within 3 months before PET examination were included in this retrospective study. PET examinations were reviewed blindly by two experienced nuclear medicine physicians who were unaware of any clinical, biological or radiological information. CA 15-3 assays performed prior to the PET examinations and all using the same technique were collected and used for doubling time calculation if (1) no therapeutic modification occurred in the meantime, and (2) the delay between assays was less than 6 months.
  
  
  RESULTS
  Median CA 15-3 blood levels were higher in the positive PET group (100 U x ml(-1)) than in the negative group (65 U x ml(-1)) (P=0.04). The likelihood of depicting recurrence was higher in patients with a short doubling time (<180 days) (P=0.05), a CA 15-3 blood level >60 U x ml(-1) (P=0.05), and when a short doubling time was associated with a CA 15-3 blood level >60 U x ml(-1) (P=0.03).
  
  
  CONCLUSIONS
  The likelihood of depicting recurrence was influenced by CA 15-3 blood level and doubling time. Further studies are required to confirm that selections of patients based on those criteria could improve the sensitivity of positron emission tomography in the detection of breast cancer recurrence, particularly in the case of low CA 15-3 blood level.
authors.affiliation: Nuclear Medicine Department, Centre François Baclesse, Caen, France. n.aide@baclesse.fr
authors.forename: Nicolas
authors.initials: N
authors.lastname: Aide
authors.forename: Virginie
authors.initials: V
authors.lastname: Huchet
authors.forename: Odile
authors.initials: O
authors.lastname: Switsers
authors.forename: Natacha
authors.initials: N
authors.lastname: Heutte
authors.forename: Thierry
authors.initials: T
authors.lastname: Delozier
authors.forename: Agnes
authors.initials: A
authors.lastname: Hardouin
authors.forename: Stéphane
authors.initials: S
authors.lastname: Bardet
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D014408:Biomarkers, Tumor / Q000097:blood*; D005260:Female; D019788:Fluorodeoxyglucose F18 / Q000493:pharmacokinetics; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D008657:Metabolic Clearance Rate; D008875:Middle Aged; D018396:Mucin-1 / Q000097:blood*; D009363:Neoplasm Proteins / Q000097:blood; D009364:Neoplasm Recurrence, Local / Q000097:blood* / Q000000981:diagnostic imaging*; D018579:Patient Selection; D049268:Positron-Emission Tomography / Q000379:methods*; D019275:Radiopharmaceuticals / Q000493:pharmacokinetics; D015203:Reproducibility of Results; D012189:Retrospective Studies; D012680:Sensitivity and Specificity
chemical_list: D014408:Biomarkers, Tumor; D018396:Mucin-1; D009363:Neoplasm Proteins; D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18