Topoisomerase IIα expression correlates with diminished disease-free survival in invasive breast cancer

Purpose: Topoisomerase IIα (Topo IIα) plays a role in DNA replication and is the molecular target for anthracyline-based chemotherapy. The purpose of this study was to evaluate the relationship between Topo IIα expression and survival in patients with invasive breast cancer. Methods and Materials: Formalin-fixed, paraffin-embedded tumor specimens from 24 women with invasive breast cancer were stained for Topo IIα expression. All women underwent mastectomy. Radiotherapy was given at the University of Utah Department of Radiation Oncology. Of the patients, 23 (96%) received chemotherapy. The level of Topo IIα expression within tumor cells was compared with clinical factors and overall survival. Results: The median percentage of tumor cells expressing Topo IIα was 70%. Increased Topo IIα tumor expression significantly correlated with diminished disease-free survival. Five-year disease-free survival was 100% for patients with p = 0.008). The level of Topo IIα expression within tumor cells correlated with T stage ( p = 0.008) but not with other pathologic factors. Conclusions: Increased Topo IIα expression significantly correlated with diminished disease-free survival in patients with invasive breast cancer. These findings may indicate a role for Topo IIα expression as a prognostic factor in breast cancer.