A population-based study of 538 patients with newly detected urinary bladder neoplasms followed during 5 years.

OBJECTIVE: To describe in detail the diagnosis and clinical course of an unselected population-based cohort of patients with newly diagnosed bladder neoplasms.

MATERIAL AND METHODS: A total of 538 patients registered in the Stockholm region with newly diagnosed primary bladder neoplasms (transitional cell carcinomas) in 1995 and 1996 were followed for at least 5 years. All hospitals and urology units in the region participated in the study. Treatment and follow-up were performed according to a standard-of-care programme. Routine pathological reports were used. Original case records were scrutinized on location in 2001. In addition, a tumour bank of freshly frozen tumour tissue was established.

RESULTS: The calculated 5-year cancer-specific survival rate for the 538 patients in the cohort was 78%. No patient (0/29) with TaG1 tumours showed progression or died of bladder cancer. Only 2/187 patients (1%) with stage Ta and grade 2A or 2B tumours died of bladder cancer. In contrast, after 5 years of follow-up, patients with TaG3 and T1G2B tumours had disease-specific death rates of 20% and 27%, respectively. The result of the first cystoscopy examination after the initial resection of non-invasive tumours was of prognostic value. Recurrent disease was present in 62% (248/402) of all patients with Ta and T1 tumours at diagnosis and patients with T1 tumours had recurrences earlier than those with Ta tumours. Moreover, 32% (35/110) of the patients who presented with T1 tumours at diagnosis progressed to muscle-invasive disease during the follow-up period. The overall prognosis for patients presenting with muscle-invasive tumours (T2+) was dismal, with 69% (80/116) of the patients dying of the disease.

CONCLUSIONS: We analysed a population-based cohort of patients with urinary bladder neoplasms in order to establish a clearly defined and unselected clinical series, with the main aims of comparing and evaluating the clinical utility of new molecular biology techniques. In the present series, TaG1 tumours behaved benignly. The disease-specific mortality rate was low for initial TaG2 tumours, intermediate for initial TaG3 and T1 tumours and high for initial T2+ tumours.