Overexpression of c-erbB-2 gene, found in 30% of human cancers, significantly correlates with number of lymph node 
metastasis, chemoresistance and early relapse. In the present study, this oncoprotein has been investigated in invasive 
transitional (TCC) and squamous (SCC) cell carcinoma of the urinary bladder with chronic schistosomiasis. From January to December 1997, 13 patients were diagnosed and except one, underwent cystectomy and were followed up till May 2000. The tumours were graded and staged using a modified TNM and WHO systems. The tumour cell type, grade and stage and patients survival were correlated with the result of the immunohistochemical study. Strong positive staining for c-erbB-2 was detected in all TCC (n=5, 100%) and exhibited 1+ (n=3) and 2+ (n=2) with over 52% and 74% staining intensity respectively. The 1+ patients were G2/G3, T2/T3 and N0/N3. Two patients survived for 10 and 24 months respectively and the third remained disease free for 36 months. 2+ positive tumours were grade G2 and T2 with nodal metastasis and the patients survived 14 and 12 months respectively. The SCC sections (n=8) were c-erbB-2 negative. One patient refused surgery, another died 12 months after surgery due to heart failure. The other patients had G1/G2, T2/T4 and N0M0 tumours and remained disease free. It appeared that the oncogenic changes in the urothelium and the biological behavior of invasive TCC, with and without chronic schistosomiasis, deserves a comparative study to evaluate c-erbB-2, with other markers, as a prognostic factor. On the other hand, c-erbB-2 negative invasive SCC, complicating urothelial metaplasia and chronic schistosomiasis, had a biological behavior different from SCC elsewhere and may explain why it is an organ-confined disease.