Fewer men have been screened for prostate cancer in recent years in the U.S. while, during the same period, the diagnosis of the condition also receded, according to findings published early online in Cancer (2018;124:2733‐2739). Additionally, the use of definitive treatments in those diagnosed dropped as well.
The value of prostate cancer screening with prostate specific antigen (PSA) testing has sparked substantial debate, at the core of which is the 2012 U.S. Preventive Services Task Force (USPSTF) recommendation against PSA testing, the findings state. The recommendation was partly based on the potential harms—such as erectile dysfunction and urinary incontinence—associated with the treatment of clinically insignificant prostate cancer with radical prostatectomy or radiation.
“Our data supports the hypothesis that fewer men with a new diagnosis of prostate cancer are choosing to be treated with surgery or radiation,” said James Kearns, MD, lead author of the study. As a result, he noted that men are avoiding the side effects of treatment.
Some of the controversy surrounding prostate cancer screening was that men who didn’t need surgery or radiation for their condition were still undergoing those treatments, explained Kearns, a urologist at the University of Washington School of Medicine in Seattle. The findings suggest that they’re likely opting instead for active surveillance for low-risk prostate cancer, he added. “If men are well-counseled regarding their specific diagnosis and all available treatment options, PSA testing needn’t lead to unnecessary treatment.”
James Kearns, MD
To examine the use of diagnostics and treatments for prostate cancer in the years surrounding the USPSTF recommendation, Kearns and his colleagues analyzed MarketScan claims, which capture more than 30 million privately insured patients in the U.S.
The team looked specifically at information related to PSA testing, prostate biopsy, prostate cancer diagnosis, and definitive local treatment in men ages 40-64 years for the years 2008-2014. Men under age 65 years may benefit most from radiation or surgery for their prostate cancer because prostate cancer tends to cause problems for men many years after diagnosis.
In the analysis of approximately 6 million men with a full year of data, PSA testing, prostate biopsy, and prostate cancer detection declined significantly between 2009 and 2014, most notably after 2011. The prostate biopsy rate per 100 patients with a PSA test decreased over the study period from 1.95 to 1.52.
Prostate cancer incidence per prostate biopsy increased over the study period from 0.36 to 0.39. Of new prostate cancer diagnoses, the proportion managed with definitive local treatment decreased from 69 percent to 54 percent. Both PSA testing and prostate cancer incidence decreased significantly after 2011.
Thoughts on Screening
“PSA testing’s a complex subject, not easily summarized by an oversimplified letter grade recommendation,” said Justin Watson, MD, a urologic oncologist at WellStar Health System in Atlanta. "Clearly, the evidence suggests a mortality benefit from screening, though we’re still striving to find the optimal strategy to maximize screening benefits while mitigating the harm of overdiagnosis.” Watson said those harms can be limited by screening the appropriate patients and being selective about who’s biopsied and who receives treatments.
“You tell a guy he doesn’t need to go to the doctor and he’s not going to go to the doctor,” added Tom Stringer, MD, a urologist at UF Health Cancer Center, University of Florida, Gainesville. Meaning fewer men are being screened, diagnosed, and treated, he noted. “That’s fine if we’re missing insignificant prostate cancer, but it’s something else if we find out later when it’s part the point of cure.”
PSA screening still identifies many men with aggressive prostate cancer that requires treatment and does so at a time that treatment can still lead to cure, said Kearns. The increased use of active surveillance is a rational response to increased diagnosis of prostate cancer that allows for individualized prostate cancer treatment rather than significant over treatment resulting in side effects, he explained.
While the findings don’t seem particularly provocative to Ryan Terlecki, MD, a urologist at Wake Forest Baptist Health, he said the issue of whether or not to screen patients remains important. The disease is scored based on the microscope appearance, using a Gleason number system. Scores previously ranged from 2-10.
“Now, however, we’ve determined that 2, 3, 4, and 5 should no longer be considered cancer,” Terlecki noted. In fact, there’s considerable debate that Gleason 6 should no longer be termed ‘cancer,’ with reasonable supporting evidence from long-term studies, he said. “Physicians will continue to use their best judgement to advise patients, but it’s important to recognize the potential for biases based on how revenues and philanthropy dollars are generated.”
In the short-term, the new USPSTF recommendations are a step in the right direction and have taken into account the widespread adoption of active surveillance, said Watson, who noted the advisability of a risk-adapted approach to screening.
Ultimately, a wholesale rejection of PSA screening is a “significant blunder, and it’s is a good thing that the pendulum seems to be moving away from its extreme position, said Watson.
“We all agree,” he continued, “that work must continue to preserve and increase our victories over prostate cancer while limiting the risks generated by screening.”