Significance of tyrosine kinase activity on malign transformation of ovarian tumors: A comparison between EGF-R and TGF-α

Epidermal growth factor (EGF) and transforming growth factor-alpha (TGF-α) are members of the polypeptide growth factor family. The epidermal growth factor-receptor (EGF-R) is a receptor tyrosine kinase of the ErbB family. Many types of cancer, including ovarian cancer, display enhanced EGF-R immunoreactivity on their cell surface membranes. Also, an increase in TGF-α synthesis and secretion usually occurs in human carcinoma cell lines. In this study, we compared the immunoreactivities of TGF-α and EGF-R in ovarian tumors and related immunohistochemical findings to the histological type of the tumors. Formalin-fixed, paraffin wax-embedded tissue sections from 40 patients who had serous-mucinous borderline tumor and serous-mucinous adenocarcinoma of the ovary (n=10 each) were stained with hematoxylin–eosin and labeled for binding of primary antibodies against TGF-α and EGF-R using an avidin–biotin–peroxidase method. A semi-quantitative grading system was used to compare immunohistochemical labeling intensities. Increased immunoreactivity of EGF-R and moderate immunoreactivity of TGF-α was detected in adenocarcinomas. There was no significant difference in the immunoreactivity of TGF-α among the histologic types of ovarian tumors. The results of this study support the hypothesis that EGF-R may be a more useful marker than TGF-α in epithelial ovarian tumors.