Tissue Microarrays as a Validation Methodology for Quality Control of HER2 Analysis by Fluorescence In Situ Hybridization
Liliana E Vasquez, Diana Canon, Yubelly Abello, Natalia Ospina, Adriana Plata, Maria M Torres, Rafael E Andrade. Hospital Universitario Fundación Santa Fe de Bogotá, Bogotá, Colombia; Universidad de los Andes, Bogotá, Colombia
Background: HER2 amplification and overexpression are predictive for prognosis and treatment response to specific therapies in breast cancer patients. It is mandatory to provide accurate results, avoiding false negative and positive. Frequently, differences on results interpretations are related to tissue sample handling and the analytical interpretation. Technical validation methods and quality control of these tests are mandatory, but they represent an additional cost that precludes their implementation in routine laboratories. The objective of this project was to evaluate the usefulness of tissue microarrays (TMAs) as a cost-effective technique for the validation of routinely molecular studies performed on HER2 in patients with breast cancer.
Design: Tissues from 326 cases were organized into 5 TMAs. Each TMA was analyzed for the amplification of the oncogene HER2 by FISH, considered the gold standard technique. The concordance between the results reported for HER2 by FISH in each of the patients and the results obtained in the TMA was statistically calculated by the Kappa analysis.
Results: The agreement was 95,4% with a Kappa value of 0,84 (almost perfect) for both the positive and negative results. The agreement between two observers was 96,5% with a Kappa value of 0,88.
Conclusions: The TMA is a useful and cost effective technology that allows reliably analyze up to 100 consecutive cases in a single mounting, and it can be implemented as a method of quality control and validation in peripheral laboratories, especially for the screening of the HER2 gene status.
Monday, March 19, 2012 1:00 PM
Poster Session II # 66, Monday Afternoon