Study Of Correlation Of P-gp,GST-π And Topo-Ⅱ In Neoadjuvant Chemotherapy Of Breast Neoplasm

Objective: To explore the relationship between P-gp, GST-Ï€and Topo-II and neoadjuvant chemotherapy for breast cancer, and the correlation of P-gp, GST-Ï€and Topo-II.Methods: The expression of P-gp, GST-Ï€and Topo-II in 60 samples formalin-fixed paraffin-embedded primary breast neoplasm received neoadjuvant chemotherapy in our hospital from January 2005 to July 2007 was examined by immunohistochemical staining with P-gp monoclonal antibody, GST-Ï€monoclonal antibody and Topo-II monoclonal antibody respectively.Results: The overall response rate to neoadjuvant chemotherapy(NACT) was 73.3%. After chemotherapy the positive rate of P-gp, GST-Ï€and Topo-II had no significant changes(P > 0.05), but the change of expression intensity of P-gp had statistic significance(P<0.05). Before chemotherapy, P-gp expression intensity was correlated with GST-Ï€(r=0.468, P<0.01), Topo-II expression intensity had no correlation with P-gp and GST-Ï€(P>0.05). After chemotherapy, P-gp expression intensity was correlated with GST-Ï€(r=0.670, P<0.01), Topo-II expression intensity had no correlation with P-gp and GST-Ï€(P>0.05). The effect of NACT had a significantly negative correlation with P-gp and GST-Ï€expression , but had a significantly positive correlation with Topo-II expression(P<0.05).Conclusions: Neoadjuvant chemotherapy should be a standard choice of local advanced breast cancer(LABC). NACT can significantly change P-gp expression intensity, improve the possibility of drug resistence. P-gp had positive correlation with GST-Ï€before and after NACT, they may have common modulate mechanism. The expression of P-gp, GST-Ï€and Topo-II as molecular markers could guide chemotherapy and predict its response in breast cancer.