Outcome of very large superficial bladder tumours: a 10-year experience

OBJECTIVES: To determine the biological behaviour of very large superficial bladder tumours (pTa, pT1) and evaluate the impact of the initial tumour weight on long-term prognosis. MATERIAL AND METHODS: Of 1569 patients who presented with bladder tumours over a 10-year period, 1070 of the tumours were superficial. Fifty-nine patients had very large tumours (resected weight >or= 15 g). Case notes were analysed to determine recurrence, progression and survival. Median follow-up was 60 months (range 1-156 months). Histological slides were reviewed for all tumours initially reported as pT1 to determine the presence of uninvolved muscle. Statistical analysis was performed using the Kaplan-Meier method to calculate progression and survival estimates. RESULTS: The overall progression and recurrence rates for very large superficial bladder tumours were 18% and 68%, respectively. The progression rates for Ta, T1, G1, G2 and G3 tumours were 4%, 28%, 0%, 20% and 50%, respectively, with highest progression rates being seen for pT1G2 and pT1G3 tumours. The progression rate was significantly influenced by initial stage (p=0.01) and grade (p=0.03). Tumour weight did not affect either recurrence, progression or cause-specific survival. There were no differences in progression and survival rates in patients with tumour weights of 15-30 and >30 g (p=0.80 and 0.07, respectively). The review of histology slides of T1 tumours showed that 7/10 cases (70%) with progression had no muscle or an inadequate amount of muscle for definitive staging. Upper urinary tract tumours were seen in only two patients (3.4%). CONCLUSIONS: Large size is not an adverse prognostic factor for patients with a superficial bladder tumour. However, these cases are difficult to stage. In view of the high rates of progression and disease-specific mortality, we recommend that very large pT1G2 bladder tumours should be considered as high-risk tumours and targeted for aggressive treatment, including early re-resection, to rule out any occult invasive disease.