P 53 and bcI2 expression in TCC of the bladder
Byrne RL., Birch P., Griffiths L., Robinson MC., Neal DE., Hamdy FC.
Introduction: p53 and bd-2 are both apoptosis-regulating genes which are gaining importance in elucidating the biological behaviour of human malignancies. Whilst an inverse correlation between bcl-2 and p53 immunoreactivity in bladder cancer specimens was shown in some studies, others found no additional predictive value in combining the results of p53 and bcl-2 immunohistochemical staining in invasive disease. The aim of this study was to investigate the detection of p53 nuclear protein accumulation and bcl-2 protein overexpression in human bladder cancer by immunohistochemistry, and their association with tumour progression. Patients and methods: Samples from 79 patients with histologically proven, newly diagnosed bladder cancer were studied using immunohistochemical techniques. Results: Fifteen patients (19%) had bcl-2-positive tumours and 32 (41%) were positive for p53. The expression of p53 was related to both tumour grade and histological stage at diagnosis; bcl-2 expression was related to tumour stage but not histological grade. Seventeen of 32 p53-positive patients (52%) had disease progression, compared with 15 of 47 (32%) who progressed with p53-negative tumours (P = 0.04). p53-positive patients had a significantly shorter time to progression (P < 0.001); 10 of 15 bcl-2-positive patients progressed, compared with 22 (34%) who were bcl-2-negative. Patients with bcl-2-positive tumours had a significantly shorter time to progression (P = 0.004). There was no correlation between p53 and bcl-2 expression. The combined expression of both p53 and bcl-2 did not affect the outcome significantly. Conclusions: This study confirms the association of p53 and bcl-2 accumulation with aggressive behaviour in bladder cancer. Expression of these proteins detected by immunohistochemistry has significant prognostic value and may be useful in clinical decision-making. © 1998 British Journal of Urology.