P53 ACCUMULATION AND C-MYC OVER-EXPRESSION IN BLADDER-CANCER

Carcinogenesis results from irreversible altrations of the physiological balance between protooncogenes and tumor suppressor genes. In this study alterations of the c-myc oncogene and the p53 tumor suppressor gene during development and progression of bladder cancer were simultaneously investigated. 185 paraffine embedded urothelial specimens were examined. Normal urothelium yielded no alterations. P53 accumulation was rare in low grade papillary tumors (6%), but c-myc overexpression was present in 61%. I 19% of the dysplasia specimens p53 accumulation was detected, while c-myc overexpression was observed in only 5%. Also in carcinoma in situ c-myc overexpression (18%) was less frequent as compared to p53 accumulation (31%). In Ta G2-4 tumors and T1 tumors the incidence of p53 accumulation was similar and slightly lower than in muscle invasive tumors. C-myc overexpression in appr. 60% of the specimens was observed in Ta G2-4, T1 and T2-4 tumors. The simultaneous analysis of both genes yielded specific patterns for the different tumor stages. Uni- and multivariate analysis of various prognostic factors in patients with superficial bladder tumors demonstrated a significant correlation between multifocal tumors, p53 accumulation and tumor progression (p < 0.001). Therefore, the detection of p53 accumulation might be of relevance for the treatment of these patients.