Correlation between the expression of oncogenes ras and c-erbB-2 and the biological behavior of bladder tumors.

Expression of the ras and the c-erbB-2 oncogene products was investigated in 56 cases of human bladder transitional cell carcinoma and 6 samples of human normal bladder tissue using an immunohistochemical method. Thirty of the 56 cases of bladder tumor were found to be immunohistologically positive with the monoclonal anti-ras p21 antibody, while 19 of 56 cases were positive with the polyclonal anti-c-erbB-2 oncoprotein antibody. All 6 controls were negative with both antibodies. The ras p21 positive staining was found more frequently in the well or moderately differentiated, superficial and non-recurrent tumors than in the poorly differentiated (p < 0.01), muscle invasive (p < 0.05) and recurrent tumors (p < 0.01), while the c-erbB-2 gene product was more commonly detected in high-grade (p < 0.01), invasive (p < 0.01) and recurrent tumors (p < 0.05). Thus, the expression of either ras or c-erbB-2 was closely associated with the histological grade, clinical stage and recurrence of bladder transitional cell carcinomas.