p53 and erbB-2 protein overexpression are associated with early invasion and metastasis in bladder cancer.

Overexpression of p53 and erbB-2 was studied by immunohistochemistry in formalin-fixed tissue samples of 179 patients with transitional cell carcinoma of the urinary bladder. p53 immunostaining was strongly correlated with tumour stage (P < 0.0001). This was driven by a marked difference in p53 expression between pTa (37% positive) and pT1 (71%) tumours, while there was no difference between pT1 and pT2-4 tumours. Similarly, a strong overall association between p53 expression and grade (P < 0.0001) was driven by a marked difference between grade 1 (28%) and grade 2 tumours (71%), and there was no significant difference between grade 2 and grade 3 tumours. Surprisingly, the frequency of erbB-2 overexpression was higher in pT1 tumours (74%) than in either pTa (49%; P = 0.0265) or pT2-T4 (56%; P = 0.0645) tumours. Both p53 and erbB-2 expression was also associated with metastasis. Metastases were found in 77% of patients with p53 positive primary tumours, but in only 50% of the patients with p53 negative primary tumours (P = 0.022). Metastases were found in 66% of patients with erbB-2 positive primaries, but in only 37% of the erbB-2 negative primaries (P = 0.020). Of 32 patients with positivity for both p53 and erbB-2, 84% developed metastases, as compared to 49% of patients with positivity for either one or neither positive (P = 0.002). We conclude that both p53 and erbB-2 overexpression are associated with early invasion in bladder cancer. Furthermore, p53 and erbB-2 may be important predictors for metastasis.