Dual immunohistochemical analysis of transforming growth factor α and epidermal growth factor receptor in breast cancer

Objective: To analyze expression characteristic of transforming growth factor α（TGFα） and its receptor （EGF receptor, EGFR） and their interaction in breast cancer, and to evaluate their respective role in tumor progression and severity along with known prognostic parameters. Methodes: TGFα and EGFR were evaluated by dual immunostaining in a series of 84 invasive ductal breast carcinoma specimens, their expression was studied in non-malignant or malignant epithelium. Univariate and multivariate statistical analyses were performed. Results: Co-expression of TGFα and EGFR was found in all of the non-malignant breast epithelia adjacent to tumors. The expression of TGFα and EGFR were found in invasive epithelial tumor cells in 76.2% and 17.8% specimens, respectively、An autocrine loop with TGFα and EGFR expression in invasive carcinomas was detected in 16.7% of cases. By χ² analysis, expression of TGFα in invasive carcinomas was correlated only with absence of estrogen receptor,whereas that of EGFR was correlated with large tumor size, inflammatory carcinoma, node involvement, Scarff-Bloom-Richardson （SBR） grade III and absence of estrogen receptor. By multivariate analysis, TGFα expression in invasive tumor cells was related to inflammatory carcinoma （P=0.048）, while EGFR expression was strongly correlated with absence of estrogen receptor （P=0.002）. Conclusion: TGFα and EGFR expression are quite different in breast carcinoma than in non-malignant tissues, and are related to poor prognostic parameters, suggesting that their interaction could play an important role in the development of breast cancer.