Expression of drug resistance related proteins in breast cancer tissues and its relationship with chemotherapy therapeutic effect

OBJECTIVE: To investigate the expression and its relationship with chemotherapy therapeutic effect of multidrug resistance protein(P-gp),breast cancer resistance protein(BCRP),lung cancer resistance protein(LRP) in the breast cancer tissue.METHODS: To examine the expression level of P-gp,BCRP and LRP in 126 case breast cancer tissues and 42 case paratumor tissues by immunohistochemistry(IHC).RESULTS: The positive expression rate of P-gp,BCRP and LRP were 41.26%(52/126),38.89%(49/126) and 65.87%(83/126);The positive expression rate of breast cancer tissues were much higher than paratumor tissues(14.28%(6/42),16.67%(7/42),19.05%(8/42)),and there were significantly differences(χ2 values were 10.147,7.020 and 27.820,and all P valuse were 0.05).The 5-year recurrence,metastasis of P-gp negative cases was significantly lower than that of positive cases after chemotherapy(P=0.001).The positive expression rate of BCRP and LRP were no significant difference recurrence metastasis and un recurrence metastasis after chemotherapy in 5-year(P0.05).The carcinoma which negatively expressed P-gp and BCRP had a longer 5-year both disease-free survival rate and overall survival rate than those of positive expression(χ2 values were 24.17,4.43,12.13 and 4.22,all P values were 0.05).The 5-year both disease-free survival and overall survival of 2 multi-protein and 3 multi-protein positive cases were significantly lower than that of a single protein expression and three negative cases(χ2 values were 7.43 and 14.30,and all P values were0.05).CONCLUSIONS: The three drug-resistance proteins are involved in the formation of multidrug resistance of breast cancer.P-gp expression may help predict of breast cancer chemotherapy therapeutic effect.