Protocol for HER2 FISH determination on PAXgene-fixed and paraffin-embedded tissue in breast cancer.
Molecular diagnostics in personalized medicine increasingly relies on the combination of a variety of analytical technologies to characterize individual diseases and to select patients for targeted therapies. The gold standard for tissue-based diagnostics is fixation in formalin and embedding in paraffin, which results in excellent preservation of morphology but negatively impacts on a variety of molecular assays. The formalin-free, non-cross-linking PAXgene tissue system preserves morphology in a similar way to formalin, but also preserves biomolecules essentially in a similar way to cryopreservation, which markedly widens the spectrum, sensitivity and accuracy of molecular analytics. In this study, we have developed and tested a protocol for PAXgene-fixed and paraffin-embedded tissues for fluorescent in situ hybridization (FISH). The implementation of a 24-h formalin postfixation step of slides from PAXgene-fixed and paraffin-embedded tissues allowed us to use the assays approved for formalin-fixed and paraffin-embedded tissues. The equivalence of the methodologies was demonstrated by FISH analysis of HER2 amplification in breast cancer cases. The 24-h postfixation step of the slides used for FISH can be well integrated in the routine diagnostic workflow and allows the remaining PAXgene-fixed and paraffin-embedded tissue to be used for further molecular testing.
CD Laboratory for Biospecimen Research and Biobanking Technologies, Institute of Pathology, Medical University Graz, Graz, Austria.|Institute of Pathology, Medical University Graz, Graz, Austria.
Lisa
L
Oberauner-Wappis
CD Laboratory for Biospecimen Research and Biobanking Technologies, Institute of Pathology, Medical University Graz, Graz, Austria.|Institute of Pathology, Medical University Graz, Graz, Austria.
Martina
M
Loibner
Institute of Pathology, Medical University Graz, Graz, Austria.
Christian
C
Viertler
Research and Development, Qiagen GmbH, Hilden, Germany.
Daniel
D
Groelz
Research and Development, Qiagen GmbH, Hilden, Germany.
Ralf
R
Wyrich
CD Laboratory for Biospecimen Research and Biobanking Technologies, Institute of Pathology, Medical University Graz, Graz, Austria.|Institute of Pathology, Medical University Graz, Graz, Austria.
Kurt
K
Zatloukal
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001943:Breast Neoplasms / Q000737:chemistry / Q000235:genetics*; D002985:Clinical Protocols; D005260:Female; D005404:Fixatives; D005557:Formaldehyde; D005784:Gene Amplification; D006801:Humans; D017404:In Situ Hybridization, Fluorescence / Q000379:methods; D008875:Middle Aged; D016612:Paraffin Embedding / Q000379:methods; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000032:analysis / Q000235:genetics*; D016707:Tissue Fixation / Q000379:methods*
D005404:Fixatives; D005557:Formaldehyde; D018719:Erb-b2 Receptor Tyrosine Kinases; C508053:ERBB2 protein, human
FISH; HER2; Postfixation of PAXgene tissue; breast cancer; molecular diagnostics