Abstract:Objective:To investigate the relationship between expression of HER4,HER2,ER and PR and evaluate them on the clinical prognosis of human breast carcinoma. Methods:The expressions of HER4,HER2,ER and PR were studied in 105 cases with breast carcinoma by using SP immunohistochemistry. The endpoint of follow-up was disease free survival(DFS). Results:HER2,HER4,ER and PR expression were detected in 105 cases with positive rates of 37.14%,20.00%,40.00%,28.27%,respectively. The expression intensity of HER2,HER4,ER and PR in breast carcinoma had no significant correlation with the age,lymph node metastasis,pathological types,TNM stage,chemotherapy of the patients(P > 0.05). HER4 can be a co-activator of ER and PR expression(P = 0.030,P = 0.028). Compared with those with HER4-positive profiles,patients with HER4-negative profiles had significantly lower DFS(P = 0.039). Patients with HER4-positive and HER2-negative expression profiles had significantly longer DFS(P = 0.000) than other groups. Conclusion:HER4 expression is an independent predictor of breast cancer. Patients with HER4-positive have longer DFS, and HER4 can be a co-activator of ER and PR.