Immunohistochemical Study for Epidermal Growth Factor Receptor and Transforming Growth Factor Alpha in Transitional Cell Carcinoma of the Urinary Bladder

Lew, Jae Hyuk; Woo, Young Nam

Abstract

To evaluate the role of epidermal growth factor receptor(EGF-R) and transforming growth factor alpha (TGF-alpha) in transitional cell carcinoma of the urinary bladder, immunohistochemical studies using monoclonal antibodies to the human EGF-R and TGF-alpha were performed on formalin fixed,paraffin-embedded tissue with the urothelium extracted from patients with TCC(59 cases) and non-TCC(13 cases). EGF-R was expressed in the outer, middle and basal layers of TCC and non-TCC urothelium. The staining intensity of EGF-R in the outer layer was not different between TCC and non-TCC urothelium. The strong staining intensity of EGF-R in the outer, middle and basal layers was noted in 5(14%), 4(11 %) and 5(14%) cases, respectively in the low grade TCC(35 cases of grade I and II ), however all the layers of 13(54%) cases of the high grade TCC(24 cases of grade III and IV) showed strong staining intensity. The strong staining intensity of EGF-R in the three layers of the superficial tumors(34 cases of Ta and T1) was noted in 6(18%), 5(15%) and 5(15%) cases, whereas 12(48%), 12(48%) and 13 (52% ) cases in the invasive tumors(25 cases of T2, T3, T4). TGF-alpha was expressed in 27(46%) cases of TCC and 11(85%) cases of non-TCC urothelium. TGF-alpha was expressed in 24(69%), 15 (43%) and 12(34% ) cases in the three layers of low grade TCC, respectively and only 3(12 %) cases in the high grade TCC. TGF-alpha expression in the outer, middle and basal layers of the superficial TCC was noted in 22(65 %), 14(41%) and 12(35%) cases, respectively, whereas that of the invasive TCC was 6 (20%), 4(16%) and 3(12%) cases, respectively. These results suggest that the distribution of EGF-R in the tumor cells are not an important factor. However, the binding capacity of EGF-R to EGF and TGF-alpha may be an important change in the carcinogenesis of the bladder TCC and the expression intensity of EGF-R and TGF-alpha in TCC cells may be an important factor to determine the biological behavior of the bladder TCC.