RESUMEN
Evaluation of HER2 (ERBB2) gene amplification or protein expression is standard of care in breast (BR) and advanced stage gastro-oesophageal cancers to identify patients eligible for anti-HER2 therapies. Here, we evaluate a rapid fluorescence in situ hybridisation (FISH) technology (HER2 instant quality (IQ) FISH pharmDx Kit) for detection of HER2 in patients with BR and gastro-oesophageal cancer using 30 FFPE samples that had been previously evaluated with the PathVysion HER2 DNA Probe Kit. Cases were scored as positive (HER2:CEN-17 ≥2.0), negative (HER2:CEN-17 <2.0) or equivocal according to the ASCO/CAP 2013 BR cancer guidelines. Ten samples were positive for HER2 amplification while 20 were negative; none were equivocal. The IQ FISH was able to detect low level amplification (HER2:CEN-17 ratio 2.4). The HER2 IQ FISH pharmDx Kit is a FDA approved kit that offers a rapid turnaround time (approximately 3.5â h) and in our laboratory was 100% concordant with prior PathVysion results.
Asunto(s)
Biomarcadores de Tumor/genética , Neoplasias de la Mama/genética , Neoplasias Esofágicas/genética , Amplificación de Genes , Hibridación Fluorescente in Situ , Receptor ErbB-2/genética , Neoplasias Gástricas/genética , Biopsia , Neoplasias de la Mama/enzimología , Neoplasias de la Mama/patología , Neoplasias Esofágicas/enzimología , Neoplasias Esofágicas/patología , Femenino , Regulación Neoplásica de la Expresión Génica , Humanos , Masculino , Valor Predictivo de las Pruebas , Juego de Reactivos para Diagnóstico , Neoplasias Gástricas/enzimología , Neoplasias Gástricas/patología , Factores de Tiempo , Regulación hacia Arriba , Flujo de TrabajoRESUMEN
BACKGROUND: HER2 fluorescence in-situ hybridization (FISH) is used in breast and gastro-esophageal carcinoma for determining HER2 gene amplification and patients' eligibility for HER2 targeted therapeutics. Traditional manual processing of the FISH slides is labor intensive because of multiple steps that require hands on manipulation of the slides and specifically timed intervals between steps. This highly manual processing also introduces inter-run and inter-operator variability that may affect the quality of the FISH result. Therefore, we sought to incorporate an automated processing instrument into our FISH workflow. METHODS: Twenty-six cases including breast (20) and gastro-esophageal (6) cancer comprising 23 biopsies and three excision specimens were tested for HER2 FISH (Pathvysion, Abbott) using the Thermobrite Elite (TBE) system (Leica). Up to 12 slides can be run simultaneously. All cases were previously tested by the Pathvysion HER2 FISH assay with manual preparation. Twenty cells were counted by two observers for each case; five cases were tested on three separate runs by different operators to evaluate the precision and inter-operator variability. RESULTS: There was 100% concordance in the scoring between the manual and TBE methods as well as among the five cases that were tested on three runs. Only one case failed due to poor probe hybridization. In total, seven cases were positive for HER2 amplification (HER2:CEP17 ratio >2.2) and the remaining 19 were negative (HER2:CEP17 ratio <1.8) utilizing the 2007 ASCO/CAP scoring criteria. Due to the automated denaturation and hybridization, for each run, there was a reduction in labor of 3.5h which could then be dedicated to other lab functions. CONCLUSION: The TBE is a walk away pre- and post-hybridization system that automates FISH slide processing, improves work flow and consistency and saves approximately 3.5h of technologist time. The instrument has a small footprint thus occupying minimal counter space. TBE processed slides performed exceptionally well in comparison to the manual technique with no disagreement in HER2 amplification status.