MOLECULAR AND IMMUNOHISTOCHEMICAL EVALUATION OF EPIDERMAL GROWTH-FACTOR RECEPTOR AND C-ERB-B-2 GENE-PRODUCT IN TRANSITIONAL-CELL CARCINOMASOF THE URINARY-BLADDER - A STUDY IN GREEK PATIENTS

In this study, the expression of epidermal growth factor receptor (EGF r) and c-erb-B-2 was evaluated in 35 formalin-fixed, paraffin-embedded cases of transitional cell carcinomas of the urinary bladder (TCCs), EGFr and c-erb-B-2 expression was assessed with immunohistochemistry, and molecular analysis of the respective genes was performed with the differential polymerase chain reaction. The results were statistically analyzed in relationship to histologic grade, stage, and clinical out come, Strong cytoplasmic expression of the EGFr using the polyclonal a ntibody Ab-4 was found in three (25%) Grade 2 and eight (67%) Grade 3 TCCs (P < 0.01). Two Grade 2 (17%) and 11 (92%) Grade 3 TCCs strongly expressed the anti-c-erb-B-2 Ab-3 antibody, None of Ta/T1 TCCs cases s howed strong expression against EGFr, in contrast to c-erb-B-2 where t wo cases (18%) were found to express an intense immunosignal. Eleven ( 85%) T2/T3 cases showed strong positivity either against EGFr or c-erb -B-2 (P < 0.001). Eleven patients died within 12 months after the diag nosis, and all of them showed strong expression of EGFr and c-erb-B-2, Amplification of EGFr and c-erb-B-2 genes was identified in one (3%) and four (11%) TCCs cases, respectively, All patients with amplified g enes died within 12 months from the date of diagnosis, Our results ind icate that simultaneous expression of EGFr and c-erb-B-2 occurs in TCC s, is related to the histologic grade and the stage of the disease, an d denotes aggressive biologic behavior.