Mortality rates have stabilized and incidence rates of late-stage disease have started to increase after 2 decades of decreasing rates. At the same time, rates of prostate-specific antigen screening have declined.
After 2 decades of decreasing prostate cancer mortality and incidence rates, mortality rates have stabilized and incidence rates of late-stage disease have started to increase.
After the introduction of prostate-specific antigen (PSA) testing, the United States saw a dramatic increase in prostate cancer incidence between 1988 and 1992. Rates have decreased since then, with an accelerated decrease in more recent years.
Researchers have associated the decline in incidence with decreased PSA screening due to the 2012 United States Preventive Services Task Force (USPSTF) recommendation against routine PSA screening. Just this month, USPSTF updated its recommendation, recommending that men aged 55 to 69 make their own decision on whether to be screened periodically after having a conversation with their physician on potential benefits and harms. The recommendation was upgraded from grade D to grade C. However, the study authors warned that this direct causation is not demonstrated and that there are several factors that affect cancer incidence and mortality.
To determine trends in prostate cancer incidence and mortality rates in respect to changes in PSA screening rates, researchers collected data from population-based US cancer registries from 2014 by age, race, and disease characteristics, representing 89% of the population. Mortality data between 1975 and 2015 were also compiled.
Long-term trends in PSA testing showed that testing rates increased rapidly after the test was first approved for the surveillance of prostate cancer patients in 1986, with incidence of newly tested men peaking in 1992. By then, 24% of men aged 50 and older had undergone at least 1 test, up from approximately 0% in 1987. The significant increase in PSA testing coincided with dramatic increases in prostate cancer incidence between 1987 and 1992. There was a sharp decline in distant-stage prostate cancer incidence between 1991 and 1994.
Starting in 2008, PSA screening rates declined for all ages and races, except for black men aged 75 and older.
Prostate cancer incidence consistently declined 6.5% per year from 2007 to 2014 for all races combined, falling from a rate of 163 new cancer cases per 100,000 to 104 new cases per 100,000. However, while incidence rates for all stages combined continued to decline between 2010 and 2014, there was an increase in incidence rates for distance disease. Rates increased from 7.8 new cases per 100,000 in 2010 to 9.2 new cases per 100,000 in 2014.
Prostate cancer mortality increased slightly before 1987 and began to increase more rapidly up until peak mortality in 1993. Following the peak, there were steady decreases in mortality rates observed for all races combined, with a greater decline among black men compared to white men. However, rates started to level off and stabilize after 2013.
“The increase in late-stage disease and the flattening of the mortality trend occurred contemporaneously with the observed decrease in PSA screening in the population,” Serban Negoita, MD, DrPH, National Cancer Institute Surveillance Research Program and lead author of the study, said in a statement. However, he noted, “Although suggestive, this observation does not demonstrate that 1 caused the other, as there are many factors that contribute to incidence and mortality, such as improvements in staging and treating cancer.”
The study also noted that declines in prostate cancer mortality among white men slowed after 1999, long before the 2012 USPSTF recommendation against routine screening.
Negoita S, feuer E, Mariotto A, et al. Annual report to the national on the status of cancer, part II: recent changes in prostate cancer trends and disease characteristics [published online Mayy 22, 2018]. Cancer. doi: https://doi.org/10.1002/cncr.31549.