title: Low specificity of cytokeratin 19 reverse transcriptase-polymerase chain reaction analyses for detection of hematogenous lung cancer dissemination.
abstract: OBJECTIVE
  Sensitive detection of systemic tumor dissemination in lung cancer patients is important for selection of appropriate treatment modalities. Based on recent promising data that showed reverse transcriptase-polymerase chain reaction (RT-PCR) analyses for cytokeratin 19 (CK-19) expression in peripheral-blood or bone marrow samples to be a rapid and highly sensitive method for detection of hematogenous tumor dissemination in patients with breast and prostate cancer, we evaluated the specificity of this assay system in lung cancer patients and a large number of healthy controls.
  
  
  METHODS
  We examined CK-19 mRNA expression by RT-PCR in 17 lung cancer cell lines and in peripheral-blood samples of 50 lung tumor patients and 65 healthy controls.
  
  
  RESULTS
  Expression of CK-19 mRNA was observed in all lung cancer cell lines and in 50% of peripheral-blood samples from lung tumor patients. However, under the experimental conditions analyzed, at least 20% of the control samples were positive for CK-19 mRNA expression.
  
  
  CONCLUSIONS
  Contrary to prior reports, RT-PCR may detect non-tissue-specific constitutive low-level (illegitimate) expression of CK-19 mRNA in peripheral-blood mononuclear (PBMN) cells in a significant number of healthy controls. This finding may not only hamper the use of this assay system in lung cancer patients, but also questions its proposed applicability in patients with other epithelial tumors such as breast and prostate cancer.
authors.affiliation: Institut für Pathologie, Berufsgenossenschaftliche Kliniken Bergmannsheil Bochum, Germany.
authors.forename: M
authors.initials: M
authors.lastname: Krismann
authors.forename: B
authors.initials: B
authors.lastname: Todt
authors.forename: J
authors.initials: J
authors.lastname: Schröder
authors.forename: D
authors.initials: D
authors.lastname: Gareis
authors.forename: K M
authors.initials: KM
authors.lastname: Müller
authors.forename: S
authors.initials: S
authors.lastname: Seeber
authors.forename: J
authors.initials: J
authors.lastname: Schütte
mesh_terms: D000328:Adult; D000368:Aged; D001483:Base Sequence; D005260:Female; D006801:Humans; D007633:Keratins / Q000235:genetics*; D007963:Leukocytes, Mononuclear / Q000737:chemistry; D008175:Lung Neoplasms / Q000097:blood / Q000235:genetics / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D008969:Molecular Sequence Data; D009362:Neoplasm Metastasis; D016133:Polymerase Chain Reaction; D012333:RNA, Messenger / Q000032:analysis* / Q000097:blood; D012680:Sensitivity and Specificity; D014158:Transcription, Genetic
chemical_list: D012333:RNA, Messenger; D007633:Keratins