Identification of tissue of origin in body fluid specimens using a gene expression microarray assay

Gregory A. Stance, Donna Coffey, Karla Alvarez, Meredith Halks-Miller, Anita Lal, Dina Mody, Tracy Koen, Todd Fairley, Federico A. Monzon

Research output: Contribution to journalArticlepeer-review

21 Scopus citations


BACKGROUND: Body fluid specimens may be the first and only pathologic specimen for clinical evaluation in metastatic cancer cases. The challenge of identifying the tissue of origin in metastatic cancer has led to the emergence of molecular-based assays, such as the microarray-based Pathwork Tissue of Origin gene expression test. The ability to use body fluid specimens in this test would be valuable in providing diagnoses to cancer patients without clearly identifiable primary sites. In the current study, the authors evaluated the Tissue of Origin Test for use with malignant effusion specimens. METHODS: A total of 27 metastasispositive body fluid specimens from different body sites, including pleural, ascites, pericardial, and pelvic wash fluids, were obtained from patients with known diagnoses. Nine specimens from nonmalignant body fluids were included as controls. RNA was extracted from formalin-fixed, paraffin-embedded (FFPE) tissue and gene expression analysis was performed with the Tissue of Origin Test. RESULTS: Seventeen of 27 metastasis- positive samples were non-necrotic with 60% tumor and yielded sufficient RNA. Of these samples, 94.1% (16 of 17) were in agreement with the available diagnosis. Of the 9 negative control samples evaluated, 7 (77.8%) demonstrated microarray expression profiles most similar to lymphoma, which is consistent with the predominance of inflammatory cells in these specimens. CONCLUSIONS: The results of the current study demonstrated that FFPE cell blocks from cytologic body fluid specimens yield adequate diagnostic material for the Pathwork test and can be used in the workup of patients with unknown primary tumors. Cancer (Cancer Cytopathol) 2012;120:62-70.

Original languageEnglish (US)
Pages (from-to)62-70
Number of pages9
JournalCancer cytopathology
Issue number1
StatePublished - Feb 25 2012


  • Cell block
  • Cytology
  • Formalin-fixed
  • Gene expression
  • Malignant effusion
  • Metastatic cancer
  • Microarray
  • Paraffin-embedded
  • Unknown primary

ASJC Scopus subject areas

  • Cancer Research
  • Oncology
  • Medicine(all)


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