Conditional Survival in Prostate Cancer in the Nordic Countries Elucidates the Timing of Improvements

SIMPLE SUMMARY: Prostate cancer (PC) is the most common male cancer, and the numbers of new cases increased hugely when prostate-specific antigen (PSA) testing became commonplace. The consequence was that the diagnostic age shifted toward younger men with less-advanced PC. Such changes are known to improve cancer survival, and in the Nordic countries, the 5-year survival for PC increased from about 60% to 90%; however, since testing stabilized, this improvement has slowed, and the 5-year survival had reached 95% by the year 2020. By analyzing survival in different periods after diagnosis, we observed that the most critical time for death was between years 1 and 5, assumably because of metastatic deaths. Some metastases are difficult to detect at diagnosis, and some arise later in the course of the disease. For continued survival, improvements in early diagnosis and more effective treatment will be required. ABSTRACT: Background: The incidence of prostate cancer (PC) increased vastly as a result of prostate-specific antigen (PSA) testing. Survival in PC improved in the PSA-testing era, but changes in clinical presentation have hampered the interpretation of the underlying causes. Design: We analyzed survival trends in PC using data from the NORDCAN database for Denmark (DK), Finland (FI), Norway (NO) and Sweden (SE) by analyzing 1-, 5- and 10-year relative survival and conditional relative survival over the course of 50 years (1971–2020). Results: In the pre-PSA era, survival improved in FI and SE and improved marginally in NO but not in DK. PSA testing began toward the end of the 1980s; 5-year survival increased by approximately 30%, and 10-year survival improved even more. Conditional survival from years 6 to 10 (5 years) was better than conditional survival from years 2 to 5 (4 years), but by 2010, this difference disappeared in countries other than DK. Survival in the first year after diagnosis approached 100%; by year 5, it was 95%; and by year 10, it was 90% in the best countries, NO and SE. Conclusions: In spite of advances in diagnostics and treatment, further attention is required to improve PC survival.