Determining True <i>HER2</i> Gene Status in Breast Cancers With Polysomy by Using Alternative Chromosome 17 Reference Genes: Implications for Anti-<i>HER2</i> Targeted Therapy

Abstract

Our results support the findings of recent pangenomic studies that true polysomy 17 is uncommon. Additional FISH studies that use probes to the SMS, RARA, and TP53 genes are an effective way to determine the true HER2 amplification status in patients with polysomy 17 and they have important potential implications for guiding HER2-targeted therapy in breast cancer.