title: Continuous quantification of HER2 expression by microfluidic precision immunofluorescence estimates HER2 gene amplification in breast cancer.
abstract: Chromogenic immunohistochemistry (IHC) is omnipresent in cancer diagnosis, but has also been criticized for its technical limit in quantifying the level of protein expression on tissue sections, thus potentially masking clinically relevant data. Shifting from qualitative to quantitative, immunofluorescence (IF) has recently gained attention, yet the question of how precisely IF can quantify antigen expression remains unanswered, regarding in particular its technical limitations and applicability to multiple markers. Here we introduce microfluidic precision IF, which accurately quantifies the target expression level in a continuous scale based on microfluidic IF staining of standard tissue sections and low-complexity automated image analysis. We show that the level of HER2 protein expression, as continuously quantified using microfluidic precision IF in 25 breast cancer cases, including several cases with equivocal IHC result, can predict the number of HER2 gene copies as assessed by fluorescence in situ hybridization (FISH). Finally, we demonstrate that the working principle of this technology is not restricted to HER2 but can be extended to other biomarkers. We anticipate that our method has the potential of providing automated, fast and high-quality quantitative in situ biomarker data using low-cost immunofluorescence assays, as increasingly required in the era of individually tailored cancer therapy.
authors: Laboratory of Microsystems, Ecole Polytechnique Fédérale de Lausanne, CH-1015, Switzerland.
authors: Diego G
authors: DG
authors: Dupouy
authors: Laboratory of Microsystems, Ecole Polytechnique Fédérale de Lausanne, CH-1015, Switzerland.|Lunaphore Technologies SA, EPFL Innovation Park-Building C, CH-1015, Lausanne, Switzerland.
authors: Ata Tuna
authors: AT
authors: Ciftlik
authors: Institute of Pathology, Centre Hospitalier Universitaire Vaudois and University of Lausanne, CH-1011 Lausanne, Switzerland.
authors: Maryse
authors: M
authors: Fiche
authors: Laboratory of Microsystems, Ecole Polytechnique Fédérale de Lausanne, CH-1015, Switzerland.|Lunaphore Technologies SA, EPFL Innovation Park-Building C, CH-1015, Lausanne, Switzerland.
authors: Déborah
authors: D
authors: Heintze
authors: Institute of Pathology, Centre Hospitalier Universitaire Vaudois and University of Lausanne, CH-1011 Lausanne, Switzerland.
authors: Bettina
authors: B
authors: Bisig
authors: Institute of Pathology, Centre Hospitalier Universitaire Vaudois and University of Lausanne, CH-1011 Lausanne, Switzerland.
authors: Laurence
authors: L
authors: de Leval
authors: Laboratory of Microsystems, Ecole Polytechnique Fédérale de Lausanne, CH-1015, Switzerland.
authors: Martin A M
authors: MA
authors: Gijs
mesh_terms: D014408:Biomarkers, Tumor / Q000235:genetics* / Q000378:metabolism; D001943:Breast Neoplasms / Q000235:genetics* / Q000378:metabolism; D005260:Female; D005455:Fluorescent Antibody Technique; D005784:Gene Amplification; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D044085:Microfluidics / Q000295:instrumentation* / Q000379:methods*; D010865:Pilot Projects; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000235:genetics* / Q000378:metabolism
chemical_list: D014408:Biomarkers, Tumor; D018719:Erb-b2 Receptor Tyrosine Kinases