Polysomy 17 in HER-2/neu Status Elaboration in Breast Cancer: Effect on Daily Practice

Abstract

A net increase in HER-2/neu gene copy number consecutive to polysomy 17 in the absence of specific gene amplification might lead to a strong protein overexpression in a small subset of breast carcinomas. HER-2/neu status determination by FISH is dependent on the criterion considered for positivity in clinical practice.