Abstract: Objective To investigate the relationship between efficacy of chemotherapy and serum Her-2/neu concentration in patients with advanced breast cancer,and to analyze its clinical significance.Methods Serum Her-2/neu concentration before and after chemotherapy collected from 66 cases of advanced breast cancer were detected by ELISA and the results were compared with Her-2/neu expression in tissues.The correlation,the efficacy of chemotherapy and time to progress(TTP) were analyzed. Results Serum Her-2/neu concentration was consistent with the expression of Her-2/neu in tumor tissues of patient with advanced breast cancer(P<0.001).The level of Her-2/neu before chemotherapy had no relation to efficacy of chemotherapy (P>0.05).Mean serum Her-2/neu concentration decreased from 33.97ng/ml to 22.11ng/ml after treatment in patient who was effective to chemotherapy,indicating the correlation to response rate of chemotherapy(P<0.001).Conclusion The changes of serum Her-2/neu concentration are significantly associated with efficacy of chemotherapy.Her-2/neu may be used as an indicator in the course of treatment Elevated serum Her-2/neu concentration before chemotherapy was correlated to shorter overall survival.

Key words: Serum Her-2/neu, Advanced breast cancer, Efficacy of chemotherapy