title: Equivocal cytology in lung cancer diagnosis: improvement of diagnostic accuracy using adjuvant multicolor FISH, DNA-image cytometry, and quantitative promoter hypermethylation analysis.
abstract: BACKGROUND
  Sometimes, cytological lung cancer diagnosis is challenging because equivocal diagnoses are common. To enhance diagnostic accuracy, fluorescent in situ hybridization (FISH), DNA-image cytometry, and quantitative promoter hypermethylation analysis have been proposed as adjuncts.
  
  
  METHODS
  Bronchial washings and/or brushings or transbronchial fine-needle aspiration biopsies were prospectively collected from patients who were clinically suspected of having lung carcinoma. After routine cytological diagnosis, 70 consecutive specimens, each cytologically diagnosed as negative, equivocal, or positive for cancer cells, were investigated with adjuvant methods. Suspicious areas on the smears were restained with the LAVysion multicolor FISH probe set (Abbott Molecular, Des Plaines, Illinois) or according to the Feulgen Staining Method for DNA-image cytometry analysis. DNA was extracted from residual liquid material, and frequencies of aberrant methylation of APC, p16(INK4A) , and RASSF1A gene promoters were determined with quantitative methylation-specific polymerase chain reaction (QMSP) after bisulfite conversion. Clinical and histological follow-up according to a reference standard, defined in advance, were available for 198 of 210 patients.
  
  
  RESULTS
  In the whole cohort, cytology, FISH, DNA-image cytometry, and QMSP achieved sensitivities of 83.7%, 78%, 79%, and 49.6%, respectively (specificities of 69.8%, 98.2%, 98.2%, and 98.4%, respectively). Subsequent to cytologically equivocal diagnoses, FISH, DNA-image cytometry, and QMSP definitely identified malignancy in 79%, 83%, and 49%, respectively. With QMSP, 4 of 22 cancer patients with cytologically negative diagnoses were correctly identified.
  
  
  CONCLUSIONS
  Thus, adjuvant FISH or DNA-image cytometry in cytologically equivocal diagnoses improves diagnostic accuracy at comparable rates. Adjuvant QMSP in cytologically negative cases with persistent suspicion of lung cancer would enhance sensitivity.
authors.affiliation: Institute of Cytopathology, Heinrich Heine University, Düsseldorf, Germany.
authors.forename: Martin
authors.initials: M
authors.lastname: Schramm
authors.forename: Christian
authors.initials: C
authors.lastname: Wrobel
authors.forename: Ingmar
authors.initials: I
authors.lastname: Born
authors.forename: Marietta
authors.initials: M
authors.lastname: Kazimirek
authors.forename: Natalia
authors.initials: N
authors.lastname: Pomjanski
authors.forename: Marina
authors.initials: M
authors.lastname: William
authors.forename: Rainer
authors.initials: R
authors.lastname: Kappes
authors.forename: Claus Dieter
authors.initials: CD
authors.lastname: Gerharz
authors.forename: Stefan
authors.initials: S
authors.lastname: Biesterfeld
authors.forename: Alfred
authors.initials: A
authors.lastname: Böcking
mesh_terms: D015331:Cohort Studies; D019175:DNA Methylation; D004273:DNA, Neoplasm / Q000235:genetics*; D006801:Humans; D017404:In Situ Hybridization, Fluorescence / Q000379:methods*; D008175:Lung Neoplasms / Q000175:diagnosis* / Q000235:genetics / Q000473:pathology; D011401:Promoter Regions, Genetic; D012015:Reference Standards
chemical_list: D004273:DNA, Neoplasm