Overexpression of topoisomerase II alpha protein is a factor for poor prognosis in patients with luminal B breast cancer.

Between May 2005 and April 2015, a total of 643 consecutive non-metastatic invasive breast cancers were evaluated for amplified using fluorescence hybridization analysis (FISH) and for TOP2A overexpression using the immunohistochemistry assay. FISH ratios of 2 or higher were designated as amplified, and TOP2A staining >10% was defined as TOP2A overexpression. The prognostic values of amplified and TOP2A overexpression were retrospectively evaluated.