Dual-colour HER2/chromosome 17 chromogenic in situ hybridisation enables accurate assessment of HER2 genomic status in ovarian tumours

Abstract

Background: Ovarian cancer is a leading cause of gynaecological cancer-related morbidity and mortality. There has been increasing interest in the potential utility of anti-human epidermal growth factor receptor 2 (anti- HER2) agents in the treatment of this disease, with the attendant need to identify suitable predictive biomarkers of response to treatment. Aims/methods: The authors studied the prevalence of HER2 genomic amplification and overexpression in 85 ovarian tumours in the local patient cohort of this study, as well as the concordance rate between immunohistochemistry, fluorescent in situ hybridisation (FISH) and a dual-colour HER2/chromosome 17 centromere chromogenic in situ hybridisation (CISH) assay. Results: The authors identified HER2 genomic amplification and protein overexpression in 35.3% (6/17) and 29.4% (5/17), respectively, of primary ovarian mucinous carcinomas. No other cancer subtypes displayed HER2 amplification or protein overexpression. The authors also found a perfect concordance between FISH and dual-colour CISH analysis (κ coefficient 1.0, p