USPSTF Backtracks, Now Says PSA Test Is 'Individual Decision'

Liam Davenport

May 08, 2018

Men aged 55 to 69 years should make an informed, individual decision on prostate cancer screening with prostate-specific antigen (PSA) testing after discussing the potential benefits and harms with their clinician, says the US Preventive Services Task Force (USPSTF) in the final version of its recommendation statement.

As previously reported by Medscape Medical News, the USPSTF had previously caused controversy by recommending against PSA-based prostate cancer screening.

However, the USPSTF has since changed its stance, and in a new draft recommendation published in spring 2017 emphasized shared decision making. The final version of that new recommendation has now been published. In it, the USPSTF concludes that the decision as to whether to undergo PSA-based screening should be made individually for each man aged 55 to 69 years, taking into account the man's values and clinical circumstances.

 

This is a C recommendation, meaning that "there is at least moderate certainty that the net benefit is small."

The task force also made a D recommendation that men aged at least 70 years not be routinely screened for prostate cancer. The D recommendation indicates that "there is moderate or high certainty that the service has no net benefit or that the harms outweigh the benefits."

Clinicians should also inform men at increased risk of developing prostate cancer, such as African African men or those with a family history of the disease, about their increased risks and the potential benefits and harms of screening.

Alex H. Krist, MD, MPH, vice chair of the USPSTF, who is a professor at the Virginia Commonwealth University School of Medicine in Richmond, said that the decision as to whether to be screened for prostate cancer is "complex."

"Men should discuss the benefits and harms of screening with their doctor, so they can make the best choice for themselves based on their values and individual circumstances," he said in a statement.

USPSTF vice chair Douglas K. Owens, MD, from the Veterans Affairs Palo Alto Health Care System, added that screening "may be the right choice" for men "who are more interested in the small potential benefit and willing to accept the potential harms.

"Men who place more value on avoiding the potential harms may choose not to be screened," he added.

The final recommendation statement was published May 8 in JAMA.

In a related editorial in JAMA Oncology, Anita D. Misra-Hebert, MD, MPH, and Michael W. Kattan, PhD, both of the Cleveland Clinic, Ohio, say that each step of a patient's journey from PSA test to potential diagnosis and treatment should "be an opportunity for a shared decision between patient and physician.

"The US health care delivery system needs a structure that not only allows, but encourages, a space for physicians and patients to engage in meaningful conversations where shared decision making has the opportunity to take place," they write.

They suggest that "new team-based care models in primary care" involving nonphysician team members or the use of "electronic medical record tools to incorporate decision aids or individualized risk prediction models" should be leveraged to aid these conversations.

"What the updated USPSTF recommendations for prostate cancer screening are asking of physicians is to take time to pause, explain what is currently known, understand patient preferences, and make the screening decision together," the editorialists conclude.

Approached for comment, Iain Frame, PhD, director of research at the charity Prostate Cancer UK, noted that there is currently no screening program for prostate cancer in the United Kingdom.

He told Medscape Medical News: "Current diagnostic tests can't distinguish early on between aggressive cancers that could go on to kill and those that may never cause any harm, meaning that the introduction of screening has the potential to do more harm than good."

The charity is therefore funding research "to develop improved diagnostic processes with the ambition that these could be rolled out as part of a screening programme within the next 5 years."

Frame said that in the meantime, men in the UK older than 50 years can have a PSA test "if they have discussed the pros and cons of the test with their GP beforehand."

He added: "Black men and men with a family history of prostate cancer who are over the age of 45 also face increased risk and should speak to their GP [general practitioner] about whether they should be tested for the disease."

Review of Evidence

To arrive at its final recommendation, the task force conducted a review of the available evidence on the use of PSA testing to screen for prostate cancer, searching PubMed, EMBASE, Web of Science, and Cochran's Registries and Databases for relevant randomized controlled trials (RCTs) and cohort studies.

They identified 63 studies in 104 publications for inclusion in the analysis, involving a total of 1,904,950 individuals. These included three "fair-quality" RCTs (n = 647,906) that assessed the impact of PSA screening on prostate cancer morbidity and mortality and all-cause mortality.

Randomization to PSA screening was associated with a significant reduction in prostate cancer mortality in only one of those studies, the European Randomized Study of Screening for Prostate Cancer, at a relative risk of 0.79.

The study also revealed that 17.8% of patients received a false positive result. Complications that required hospitalization occurred in 0.5% to 1.6% of men who underwent biopsy after an abnormal screening result.

The researchers calculated that, overall, from 20.7% to 50.4% of screen-detected cancers were overdiagnosed. Moreover, treatment was associated with an increased risk for complications, including erectile dysfunction, urinary incontinence, and bowel symptoms, compared with conservative management.

However, they found that there was "adequate evidence" that in men aged 55 to 69 years, PSA-based screening may prevent 1.3 deaths from prostate cancer per 1000 men screened over approximately 13 years.

In addition, it was estimated that screening programs may prevent approximately three cases of metastatic prostate cancer per 1000 men screened.

The USPTSF notes that these findings are to be considered in light of the risk of long-term urinary incontinence followed radical prostatectomy. Approximately one fifth of men who undergo the procedure experience thie adverse event. In addition, two thirds of men experience long-term erectile dysfunction.

The decision to be screened for prostate cancer should be an individual one. The USPSTF

Consequently, the USPSTF concludes that men aged 55 to 69 years should be offered PSA-based screening, but that "the decision to be screened for prostate cancer should be an individual one," and that men aged 70 years and older should not undergo screening.

The recommendations highlight that the "most important" prostate cancer risk factors are "older age, African American race, and family history of prostate cancer."

They note that men aged 55 to 69 years "should have an opportunity to discuss the potential benefits and harms of screening with their clinician" before making the decision, and that their "values and preferences" should be taken into account.

The final recommendation statement points out that "many men will experience potential harms of screening, including false-positive results that require additional testing and possible prostate biopsy; overdiagnosis and overtreatment; and treatment complications, such as incontinence and erectile dysfunction.

"In determining whether this service is appropriate in individual cases, patients and clinicians should consider the balance of benefits and harms on the basis of family history, race/ethnicity, comorbid medical conditions, patient values about the benefits and harms of screening and treatment-specific outcomes, and other health needs," the task force comments.

"Clinicians should not screen men who do not express a preference for screening and should not routinely screen men 70 years and older," it warns.

Conservative Management for Lower-Risk Patients

The publication of the USPSTF final recommendation for prostate cancer screening is accompanied by numerous editorials in the various JAMA journals.

In a JAMA editorial, H. Ballentine Carter, MD, Department of Urology, Johns Hopkins Hospital, Baltimore, Maryland, says placing emphasis on higher-risk individuals in the final recommendation underlines the fact that lower-risk patients should receive conservative management.

"By virtue of their relationship with patients, primary care physicians are in a unique position to help ensure that men diagnosed with favorable-risk disease (Gleason score 6 cancer grade on biopsy, and PSA level <10 ng/mL) are presented a balanced message regarding management options," Carter writes.

"This message should emphasize that active surveillance, not surgery or radiotherapy, is the preferred option for most men with favorable-risk prostate cancer."

Carter also notes that novel data, new ways of identifying patients at risk for an aggressive phenotype, the updating of disease staging, and improvements in prostate cancer treatment mean that PSA-based screening "will continue to evolve." He adds that "it is incumbent on patients and physicians to be informed of these changes as they become available."

In an editorial in JAMA Internal Medicine, Richard M. Hoffman, MD, MPH, from the Holden Comprehensive Cancer Center, University of Iowa Carver College of Medicine, Iowa City, describes the introduction of PSA testing as "a disruptive event in US healthcare."

He says that it dramatically increased the incidence of early-stage prostate cancer "at a time when there was scant evidence to inform decisions about whether or how to treat these cancers.

"The PSA era has also provided an edifying message, effectively promulgated by the USPSTF, that cancer-screening decisions can be complex, controversial, and consequential," he writes.

"We now better appreciate that prostate cancer screening is associated with benefits and harms at both the population and individual levels."

He notes that, "while PSA is an imperfect tumor marker, it is currently the most widely offered and studied prostate cancer screening test" and that "by mimimizing the risks of unwanted testing and treatments" and by supporting effective treatments, "shared decision making for PSA screening may help maximize the net benefits of screening."

In an editorial in JAMA Surgery, Peter R. Carroll, MD, MPH, from the University of California, San Francisco–Helen Diller Family Comprehensive Cancer Center, takes issue with some of the calculations used by the task force.

He argues that the USPSTF assertion that screening would prevent only 1.3 deaths and two metastatic cancers per 1000 men screened over 13 years "underestimates the effect of screening for many.

"The benefits might be greater over a 20- to 30-year follow-up," he argues, and states that this may be of more relevance to younger men or those in "excellent health."

Moreover, he believes that the USPSTF does not "address contemporary early detection strategies, which preserve the benefits of early detection and minimize the risks."

As an example, Carroll points to the National Comprehensive Network panel on early prostate cancer detection, which offers "a refined strategy for screening" in which an early baseline PSA measurement is performed at age 45 years. This measurement can then guide later testing.

Nevertheless, Carroll concludes that the USPSTF recommendation for screening "has restarted a national discussion on prostate cancer early detection.

"The Task Force deserves credit for this more balanced, fairer approach. The message now is not 'no screening,' but 'smarter screening,' preserving benefits and reducing harms," he concludes.

JAMA. 2018;319:1901-1913. Full text

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