1. Mass spectrometry-based quantitation of Her2 in gastroesophageal tumor tissue: Comparison to IHC and FISH
- Author
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Peng Xu, Yung-Jue Bang, Adele Blackler, Emma Whitcomb, Shu-Yuan Xiao, Jamar Uzzell, John Hart, Kathleen Bengali, Fabiola Cecchi, Wei-Li Liao, Emily O'Day, Daniel V.T. Catenacci, Sheeno Thyparambil, David Krisman, Marlene Darfler, Todd Hembrough, Lei Zhao, Jon Burrows, Les Henderson, and Sang Mee Lee
- Subjects
musculoskeletal diseases ,0303 health sciences ,Receiver operating characteristic ,medicine.diagnostic_test ,business.industry ,Selected reaction monitoring ,Mass spectrometry ,Molecular biology ,03 medical and health sciences ,0302 clinical medicine ,Trastuzumab ,030220 oncology & carcinogenesis ,medicine ,%22">Fish ,Immunohistochemistry ,Multiplex ,business ,skin and connective tissue diseases ,human activities ,neoplasms ,030304 developmental biology ,medicine.drug ,Fluorescence in situ hybridization - Abstract
Background: Trastuzumab showed survival benefit for Her2-positive gastroesophageal cancers (GEC). Immunohistochemistry (IHC) and fluorescence in situ hybridization (FISH) currently determine eligibility for trastuzumab-based therapy. However, both assays are low throughput with various limitations. Methods: We developed a selected reaction monitoring mass spectrometric (SRM-MS) assay and quantified levels (amol/ug) of Her2-SRM in cell lines (n=27) and GEC tissues (n=139). We compared Her2-SRM expression with IHC/FISH, seeking to determine optimal SRM expression cut-offs to identify HER2 amplification. Results: After demonstrating assay development, precision, and stability, Her2-SRM measurement was observed to be highly concordant with HER2/CEP17 ratio, particularly in a multivariate regression model adjusted for SRM-expression of Met, Egfr, Her3, and HER2-heterogeneity covariates, and their interactions (cell lines r2=0.9842; FFPE r2=0.7643). In GEC tissues, Her2-SRM was detected in 71.2% of cases, and 12.3% were identified as ‘HER2+’. ROC curves demonstrated HER2-SRM levels to have high specificity (100%) at an upper-level cut-off of >750 amol/µg and sensitivity (75%) at lower-level cut-off of
- Published
- 2015
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