The authors note that several measures have to be analyzed to assess the population-based progress of cancer-care, and a previous template for analyses had been proposed consisting of incidence, survival and mortality (using the SEER registry in the United States). When it was applied to bladder cancer, it confirmed that, for all three measures, there was no significant change.
In this study, the authors apply that same template to a Swedish national dataset. The Swedish National Registry of Urinary Bladder Cancer (SNRUBC) was started in 1997 and is a nation-wide quality database, covering more than 95% of cancer diagnoses. In the time period up to 2016 (20 years), a total of 41,097 new cases were recorded in the register. For patients with non-muscle invasive bladder cancer (NMIBC), a detailed five year follow-up is performed, including endpoints such as recurrence and progression (since 2005).
Their analysis shows that the number of new cases increased by 40% since 1997.
The mortality rate during this period was stable; approximately 7 deaths per 100,000 inhabitants.
The relative and observed survival was stable until 2012; after 2012, a significant improvement (p<0.001) occurred. However, on the curves shown, it looks there was a steady improvement in survival outcomes by era.
The stage-group specific survival trends show that this improvement is found in all categories of bladder cancer, and is independent of age and gender. But again, there was a steady increase in survival in all the graphs, with the greatest improvement appearing to be in male patients and patients > 64. So, perhaps those are the primary drivers for the overall improvement.
Unfortunately, besides providing overarching statements of improved survival, the authors don’t delve into the etiology of this improvement. Also, with better imaging technology and greater awareness, perhaps this just represent lead-time bias?
Speaker: P-U. Malmström
Co-Authors: Liedberg F., Sherif A., Ströck V., Hosseini-Aliabad A., Jahnson S., Aljabery F., Gårdmark T.
Written by: Thenappan Chandrasekar, MD, Clinical Fellow, University of Toronto, Twitter: @tchandra_uromd, at the 2018 European Association of Urology Meeting EAU18, 16-20 March, 2018 Copenhagen, Denmark