Objective: The aim of this study was to evaluate the use of intravesical treatment and cancer-specific survival of patients with primary carcinoma in situ (CIS).
Materials and methods: Data acquisition was based on the Swedish National Registry of Urinary Bladder Cancer by selecting all patients with primary CIS. The analysis covered gender, age, hospital type and hospital volume. Intravesical treatment and death due to bladder cancer were evaluated by multivariate logistic regression and multivariate Cox analysis, respectively.
Results: The study included 1041 patients (median age at diagnosis 72 years) with a median follow-up of 65 months. Intravesical instillation therapy was given to 745 patients (72%), and 138 (13%) died from bladder cancer during the observation period. Male gender [odds ratio (OR) = 1.56, 95% confidence interval (CI) 1.13-2.17] and treatment at county (OR = 1.65, 95% CI 1.17-2.33), university (OR =2.12, 95% CI 1.48-3.03) or high-volume (OR = 1.92, 95% CI 1.34-2.75) hospitals were significantly associated with higher odds of intravesical instillations. The age category ≥80 years had a significantly lower chance of receiving intravesical therapy (OR = 0.44, 95% CI 0.26-0.74) and a significantly higher risk of dying from bladder cancer (hazard ratio = 3.03, 95% CI 1.71-5.35).
Conclusion: Significantly more frequent use of intravesical treatment of primary CIS was found for males and for patients treated at county, university and high-volume hospitals. Age ≥80 years was significantly related to less intravesical treatment and poorer cancer-specific survival.
Keywords: Cancer-specific survival; intravesical treatment; primary CIS.