Local recurrence and progression of non-muscle-invasive bladder cancer in Sweden: a population-based follow-up study.

OBJECTIVE: The aim of this study was to investigate recurrence and progression of non-muscle-invasive bladder cancer (NMIBC) in a large population-based setting.

MATERIALS AND METHODS: Patients with bladder cancer (stage Ta, T1 or carcinoma in situ) diagnosed in 2004-2007 (n = 5839) in Sweden were investigated 5 years after diagnosis using a questionnaire. Differences in time to recurrence and progression were analysed in relation to age, gender, tumour stage and grade, intravesical treatment, healthcare region, and hospital volume of NMIBC patients (stratified in three equally large groups).

RESULTS: Local bladder recurrence and progression occurred in 50 and 9% of the patients, respectively. The rate of local recurrence was 56% in the southern healthcare region compared to 37% in the northern region. A multivariate Cox proportional hazards model, adjusting for age, gender, tumour stage and grade, intravesical treatment, healthcare region and hospital volume, showed that recurrence was associated with TaG2 and T1 disease, no intravesical treatment and treatment in the southern healthcare region, but indicated a lower risk of recurrence in the northern healthcare region. Adjusting for the same factors in a multivariate analysis suggested that increased relative risk of progression correlated with older age, higher tumour stage and grade, and diagnosis in the Uppsala/Örebro healthcare region, whereas such risk was decreased by intravesical treatment (relative risk 0.72, 95% confidence interval 0.55-0.93, p = 0.012).

CONCLUSIONS: The incidence of NMIBC recurrence and progression was found to be high in Sweden, and important disparities in outcome related to care patterns appear to exist between different healthcare regions.