title: Analysis of SHOX2 methylation as an aid to cytology in lung cancer diagnosis.
abstract: OBJECTIVE
  The Epi proLung® BL Reflex Assay [short stature homeobox gene two methylation assay (SHOX2 assay)] (Epigenomics AG, Berlin, Germany) utilizes quantitative methylation-sensitive real-time polymerase chain reaction (QMSP) for the quantification of methylated short stature homeobox gene two (SHOX2) DNA. In the present study, the diagnostic utility of the SHOX2 assay was tested with regard to cytology for different cytological diagnostic categories to assess whether it can complement the cytological examination and the DNA methylation marker panel targeting the gene promoters of adenomatous polyposis coli 1A (APC), cyclin-dependent kinase inhibitor-2A (p16(INK4A)) and Ras association domain family protein 1 (RASSF1A) regarding lung cancer detection in bronchial aspirates.
  
  
  METHODS
  Prospectively collected DNA from 169 patients (cytological diagnosis: 47 tumor-positive, 56 equivocal and 66 tumor-negative) was analyzed for SHOX2 DNA methylation utilizing QMSP. Patients were followed-up for a period of 11 months maximum.
  
  
  RESULTS
  When equivocal diagnoses were categorized as tumor-positive, cytology and SHOX2 DNA methylation achieved 72% and 64% sensitivity and 63% and 98% specificity, respectively. SHOX2 DNA methylation identified 66% of the patients with cancer subsequent to a cytological equivocal diagnosis. SHOX2 complements the cytological diagnosis and the methylation marker panel.
  
  
  CONCLUSIONS
  The assay could be of use for the improvement of diagnostic accuracy if applied subsequent to equivocal or negative cytology (sensitivity=69%, specificity=98%). Furthermore, the SHOX2 assay can complement a methylation-based marker panel.
authors.affiliation: Department of Cytopathology, Institute of Pathology, Heinrich Heine University, Düsseldorf, Germany.
authors.forename: Peter
authors.initials: P
authors.lastname: Ilse
authors.affiliation: Department of Cytopathology, Institute of Pathology, Heinrich Heine University, Düsseldorf, Germany.
authors.forename: Stefan
authors.initials: S
authors.lastname: Biesterfeld
authors.affiliation: Department of Cytopathology, Institute of Pathology, Heinrich Heine University, Düsseldorf, Germany.
authors.forename: Natalia
authors.initials: N
authors.lastname: Pomjanski
authors.affiliation: Department of Cytopathology, Institute of Pathology, Heinrich Heine University, Düsseldorf, Germany.
authors.forename: Christian
authors.initials: C
authors.lastname: Wrobel
authors.affiliation: Department of Cytopathology, Institute of Pathology, Heinrich Heine University, Düsseldorf, Germany.
authors.forename: Martin
authors.initials: M
authors.lastname: Schramm
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D014408:Biomarkers, Tumor / Q000235:genetics* / Q000378:metabolism; D019175:DNA Methylation; D004273:DNA, Neoplasm / Q000235:genetics / Q000378:metabolism; D018398:Homeodomain Proteins / Q000235:genetics* / Q000378:metabolism; D006801:Humans; D008175:Lung Neoplasms / Q000175:diagnosis* / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D008745:Methylation; D008875:Middle Aged
chemical_list: D014408:Biomarkers, Tumor; D004273:DNA, Neoplasm; D018398:Homeodomain Proteins; C484664:SHOX2 protein, human
keywords: APC; Cytology; DNA methylation; RASSF1A; SHOX2; biomarker; bronchial aspirates; lung cancer; p16INK4A; quantitative methylation-specific PCR