Objective: At present, there are no predictors of tumour behaviour for grade (G) 2 pTa transitional cell carcinomas (TCC) of the bladder. Here we analyse the prognostic relevance of histopathological grading and the immunohistochemical detection of p53 and p21/WAF1.
Methods: 70 patients were newly diagnosed with G2 pTa TCC of the bladder based on transurethral resection specimens. Two pathologists, blinded with respect to the clinical outcome, confirmed the initial grade and subclassified the G2 lesions into G2a and G2b carcinomas based on the degree of nuclear atypia and the number of mitoses. Immunoreactivity for p53 and p21/WAF1 was evaluated semiquantitatively.
Results: There were 52 G2a and 18 G2b tumours, mean follow-up was 49.2 months. Of all patients, 31.4% remained tumour-free, 48.6% recurred with the same tumour grade and stage, and 20.0% showed tumour progression. Patients with G2a tumours developed tumour progression in 13% in contrast to 39% with G2b lesions (p = 0.037). Of 21 p53-positive tumours, 33% (7/21) developed progressive disease, whereas 14% (7/49) of p53-negative patients showed tumour progression (p = 0.102). Neither p21/WAF1 expression alone nor the combination of p53 and p21/WAF1 correlated with clinical outcome.
Conclusion: The more detailed grading system but not p53 or p21/WAF1 immunohistochemistry was found to be an independent prognostic factor for tumour progression.