[Immunohistochemical studies on the expression of epidermal growth factor (EGF) in human colorectal cancers]

The expression of epidermal growth factor (EGF) was studied immunohistochemically in a total of 92 human colorectal cancers to examine whether EGF was expressed in relation to its degrees of malignancy. Significantly high incidence of EGF was observed in advanced cancers than in early cancers. In the tissues of advanced cancers, tumor cells having EGF-immunoreactivity tended to be more frequently and intensely observed in deeply invasive tumor cells than in superficial tumor cells. Regarding macroscopic and histologic types, incidence of EGF-immunoreactivity was significantly higher in infiltrating types and in differentiated types than in localized types and in poorly differentiated types, respectively. Cases with poor prognosis and in advanced stages showed high positive rate of EGF-immunoreactivity. These results suggest that the expression of EGF may serve as a biologic marker for the degree of malignancy in human colorectal cancers.