Topoisomerase II alpha expression correlates with diminished disease-free survival in invasive breast cancer.
OBJECTIVE
Topoisomerase II alpha (Topo II alpha) 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 II alpha expression and survival in patients with invasive breast cancer.


METHODS
Formalin-fixed, paraffin-embedded tumor specimens from 24 women with invasive breast cancer were stained for Topo II alpha 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 II alpha expression within tumor cells was compared with clinical factors and overall survival.


RESULTS
The median percentage of tumor cells expressing Topo II alpha was 70%. Increased Topo II alpha tumor expression significantly correlated with diminished disease-free survival. Five-year disease-free survival was 100% for patients with <70% of breast cancer cells expressing Topo II alpha compared with 42% for patients with > or =70% Topo II alpha expression (p = 0.008). The level of Topo II alpha expression within tumor cells correlated with T stage (p = 0.008) but not with other pathologic factors.


CONCLUSIONS
Increased Topo II alpha expression significantly correlated with diminished disease-free survival in patients with invasive breast cancer. These findings may indicate a role for Topo II alpha expression as a prognostic factor in breast cancer.
O'Connor
John K
JK
Radiation Oncology, Tulane Cancer Center, Tulane University School of Medicine, New Orleans, LA, USA. joconno@yahoo.com
Hazard
Lisa J
LJ
Avent
James M
JM
Lee
R Jeffrey
RJ
Fischbach
Jennifer
J
Gaffney
David K
DK
D000328:Adult; D000951:Antigens, Neoplasm / Q000378:metabolism*; D014408:Biomarkers, Tumor / Q000378:metabolism*; D001943:Breast Neoplasms / Q000201:enzymology* / Q000401:mortality* / Q000473:pathology / Q000628:therapy; D018270:Carcinoma, Ductal, Breast / Q000201:enzymology / Q000401:mortality / Q000473:pathology; D017024:Chemotherapy, Adjuvant; D004250:DNA Topoisomerases, Type II / Q000378:metabolism*; D004268:DNA-Binding Proteins / Q000378:metabolism*; D018572:Disease-Free Survival; D005260:Female; D006801:Humans; D008408:Mastectomy; D018714:Radiotherapy, Adjuvant
D000951:Antigens, Neoplasm; D014408:Biomarkers, Tumor; D004268:DNA-Binding Proteins; D004250:DNA Topoisomerases, Type II