HER2 and topoisomerase IIalpha: possible predictors of response to neoadjuvant chemotherapy for breast cancer patients.
BACKGROUND
Surrogate markers may be used to assess the response to neoadjuvant treatment. The association between HER2 overexpression and favorable response to specific therapy in breast cancer is controversial, and the mechanism unclear. The purpose of the study was to evaluate HER2 and topoisomerase IIalpha (Topo IIalpha) as candidates for predicting the response to neoadjuvant chemotherapy in breast cancer patients.


METHODS
Between 1999 and 2006, seventy-six breast cancer patients who had received neoadjuvant chemotherapy were studied. Regimens including either CEF (cyclophosphamide, epirubicin, 5-fluorouracil) or CMF (cyclophosphamide, methotrexate, 5-fluorouracil) were given in more than three cycles to this group of patients. Protein expression of HER2 and Topo IIalpha were determined by immunohistochemistry. The primary endpoint was pathological and clinical response.


RESULTS
Of 76 primary breast cancer samples, 27 (35.5%) showed overexpression of either HER2 (25%) or Topo IIalpha protein (10.5%), whereas in 7 tumors (9.2%) both proteins were found to be overexpressed. Ten patients (13.2%) had a clinical complete response and 21 (27.6%) had a clinical partial response. Five women (6.6%) had a pathological complete response, 5 (6.6%) had microscopic residual disease, and 46 (60.5%) had macroscopic residual disease. HER2 and Topo IIalpha overexpression was significantly associated with a favorable response (P < 0.001 and P = 0.005 respectively).


CONCLUSIONS
Our study suggests that HER2 and Topo IIalpha overexpression could be predictors of the response to neoadjuvant chemotherapy in both the CEF and CMF arms.
Zhu
Li
L
Department of Surgery, Ruijin Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai 200025, China.
Li
Ya-fen
YF
Chen
Wei-guo
WG
He
Jian-rong
JR
Peng
Chen-hong
CH
Zhu
Zheng-gang
ZG
Li
Hong-wei
HW
D000328:Adult; D000368:Aged; D000951:Antigens, Neoplasm / Q000032:analysis* / Q000235:genetics; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use; D001943:Breast Neoplasms / Q000737:chemistry / Q000188:drug therapy*; D004250:DNA Topoisomerases, Type II / Q000032:analysis* / Q000235:genetics; D004268:DNA-Binding Proteins / Q000032:analysis* / Q000235:genetics; D005260:Female; D006801:Humans; D008875:Middle Aged; D020360:Neoadjuvant Therapy; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000032:analysis* / Q000235:genetics; D012189:Retrospective Studies
D000951:Antigens, Neoplasm; D004250:DNA Topoisomerases, Type II; D004268:DNA-Binding Proteins; D018719:Erb-b2 Receptor Tyrosine Kinases; C508053:ERBB2 protein, human