National incidence and survival of patients with non-invasive papillary urothelial carcinoma: a Danish population study

OBJECTIVE: To estimate national relative survival of low and high grade non-invasive papillary urothelial carcinoma (Ta LG and Ta HG) and urothelial carcinoma in situ (CIS).

MATERIALS AND METHODS: All Danish citizens (17,941 patients) with a primary urothelial bladder tumour diagnosis in the period 2000- 2010 were followed until 1 January 2016 and recorded in the Danish Bladder Cancer Cohort database. Survival was compared to the background population matched on age and gender and adjusted by civil status, income, education, and comorbidity.

RESULTS: Patients treated in daily practice with Ta LG have 46% (HR = 1.46 (1.42-1.51) p < 0.001) higher risk of death compared to a background population matched for age and gender. This risk of death ceases to 28% (HR = 1.28 (1.24-1.32) p < 0.001) after adjustment for civil status, income, education, and comorbidity. Relative survival of Ta LG patients is 0.94 (0.93-0.95). These estimates are constant throughout the observation period. Significantly higher mortality is found for patients with Ta HG and CIS, but, in contrast to Ta LG, the relative risk of death of Ta HG (HR = 1.79 (1.69-1.90) p < 0.001) and CIS (HR = 2.02 (1.79-2.26) p < 0.001) decreases considerably after 5 years survival (HR = 1.43 (1.30-1.57) p < 0.001 and HR = 1.64 (1.36-1.98) p < 0.001, respectively).

CONCLUSION: Patients with Ta LG have a continuous lower survival and a 28% higher risk of death at any time compared to a matched background population when treated in daily practice.