For this study, the authors identified men diagnosed with prostate cancer from 1980-2011 in the Surveillance, Epidemiology, and End Results (SEER) program and from 1995-2011 in the Danish Prostate Cancer Registry (DaPCaR), and stratified patients according to period of diagnosis. Age-standardized incidence (according to the world standard population) and 5-year mortality rates were calculated for both cohorts using competing-risk analysis treating PCa-specific death and other-cause death as competing events.
There were 29,555 men in the SEER database and 6,874 men in the DaPCaR database with de-novo metastatic prostate cancer who were identified. The incidence of de-novo metastatic prostate cancer decreased from 12.0 to 4.4 per 100,000 men in the SEER cohort, while a moderate increase from 6.7 to 9.9 per 100,000 was observed in the DaPCaR cohort over the time period of the study. Five-year prostate cancer-specific mortality in SEER was stable from 1980 to 1994 and increased slightly in the latest periods studied (54.2% to 61.0%, p<0.0001), while 5-year disease-specific mortality decreased by 16.6% (from 73.4% to 64.0%, p<0.0001) in the DaPCaR cohort.
Dr. Helgstrand concluded that despite earlier detection, de-novo metastatic prostate cancer remains associated with a high risk of 5-year prostate cancer-specific mortality. They suggest that the reduced 5-year prostate cancer-mortality in DaPCaR is largely explained by lead-time. Early detection decreased the incidence of de-novo metastatic prostate cancer, as observed in the SEER cohort and might be a key explanation for the reduced prostate cancer-specific mortality observed in the U.S. As Dr. Helgstrand cautions, this must, however, be weighed against the unsolved issue of over-detection and overtreatment of indolent prostate cancer.
Presented by: John T. Helgstrand, Copenhagen University Hospital, Copenhagen, Denmark
Co-Authors: Røder M3, Klemann N, Toft B, Lichtensztajn D, Brooks J, Brasso K, Vainer B, Iversen P
Written by: Zachary Klaassen, MD, Urologic Oncology Fellow, University of Toronto, Princess Margaret Cancer Centre, twitter: @zklaassen_md at the 2018 European Association of Urology Meeting EAU18, 16-20 March, 2018 Copenhagen, Denmark