The PSA test – a measure of prostate-specific antigen levels in the blood – is used to screen for prostate problems, and is often the first test for men who are worried about prostate cancer. While elevated PSA levels could be an early warning sign of prostate cancer, a rise in PSA can also be caused by other factors including urinary infections, prolonged exercise, and prostatitis.
Routine screening to monitor prostate cancer risk is therefore highly controversial, and screening recommendations vary across countries. For example, the US Preventive Services Task Force recommends against screening in all men, whereas many guidelines advocate shared decision-making between physicians and patients.
In a forum article published today in BMC Medicine as part of our Spotlight on prostate cancer article collection, we sought to determine the experts’ views on what’s next for PSA screening. Guest Editors Sigrid Carlsson and Andrew Vickers questioned some of the world’s key opinion leaders on exactly who should be screened for prostate cancer, and when this should be done.
Opinions from the screening proponents
. . .in my view, the time for population-based screening has not come and may never do so
Michael Leapman and Peter Carroll, who are generally perceived as proponents of prostate cancer screening, explained that there is compelling evidence showing that PSA screening is linked to reduced prostate cancer deaths.
Acknowledging the issue that routine PSA screening would lead to the detection of clinically insignificant prostate cancer – resulting in overtreatment in some men – Leapman and Carroll advocate that for asymptomatic men, patients and physicians should together discuss the pros and cons of screening, taking the patient’s preferences and risk factors into account.
Fritz Schröder explained that the chance of diagnosing clinically insignificant prostate cancer – disease that is unlikely to progress clinically or cause symptoms – through PSA screening is approximately 40%. Summarizing that “in my view, the time for population-based screening has not come and may never do so”, Schröder also recommended a shared decision-making approach to PSA screening using the SIU decision aid.
The skeptics’ views
Do I believe that PSA testing should be abandoned? Of course not, screening clearly benefits some men
Vickers and Carlsson also asked those who have been considered skeptical about prostate cancer screening about what they think current policy should be. Peter Albertsen outlined some of the problems with using PSA as a screening tool, including the high rate of false-positive results and the possibility of missing lethal tumors. However, Albertsen also advocated a shared decision-making approach, emphasizing that:
“Do I believe that PSA testing should be abandoned? Of course not, screening clearly benefits some men”
Albertsen concluded that he strongly supports the American Urological Association guidelines, but we need to further refine the group of men who should be tested and develop a best practice screening and treatment algorithm.
Dragan Ilic discussed the results of a recent meta-analysis of five trials examining the effectiveness of population-based screening, emphasizing that there was no significant difference in mortality between those men who underwent screening and those who did not.
Turning to focus on the benefits and harms of screening for the individual, Ilic shared the other authors’ recommendations that the decision about whether to undergo PSA testing should be shared between patients and physicians.
Ilic favored a discussion of the results of key screening trials during patient trials, recommending that decision aids should be used to ensure patients are fully informed of the risks and benefits associated with screening.
Shared decision-making is key!
Shared decision-making can help avoid throwing out the baby – and the PSA test – with the bathwater
Michael Barry & Dominick Frosch
Michael Barry and Dominick Frosch, experts in implementing shared decision-making in primary care, explained that different men will see the balance of benefits and harms differently, and agreed that decision aids are very important in supporting a shared decision-making process in primary care.
Barry and Frosch explained that the implementation of shared decision-making between patients and physicians requires a cultural shift from a paternalistic medical culture to sharing decisions on a routine basis. The authors emphasize that this shift is already underway, concluding that:
“We can definitely envision a future when millions of patients engage in shared decision making around cancer screening with their clinicians, facilitated by the availability of high-quality decision support”
Taking all the experts’ views into account, Vickers and Carlsson concluded that there is agreement among the authors that PSA screening should not be given routinely to all men, and shared decision-making between patients and physicians is essential before the PSA test can be given.
The Guest Editors highlight conflicting opinions from the different experts on how exactly shared decision-making should take place, particularly regarding the use of decision aids and the discusison of complex trial results in primary care. Vickers and Carlsson conclude that:
“It is time to end sterile, for-and-against debates and focus on making sure that contemporary PSA screening practice follows best evidence”
BMC Medicine’s Spotlight on prostate cancer article collection, guest edited by Sigrid Carlsson and Andrew Vickers, remains open for research submissions covering all areas of prostate cancer research and treatment. Please send any pre-submission queries to firstname.lastname@example.org.
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2014 median turnover times: initial decision three days; decision after peer review 41 days