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Primary care physicians (PCPs) have scaled back their prostate-specific antigen (PSA) testing following the 2012 U.S. Preventive Services Task Force (USPSTF) recommendation against routine PSA screening for all men, but use of PSA testing among urologists has barely budged since that time.

In patients 50 to 74, the use of PSA testing after the USPSTF recommendation declined by more than half among visits to PCPs but dropped by only about 10% among urologist visits, Michael E. Zavaski, MD, of in Boston, and co-authors reported online in .

The USPSTF , citing concern that the expected harms of PSA screening (i.e., overdiagnosis and potential harms of treatment) outweigh the potential benefit. It assigned a grade "D" rating, discouraging the use of PSA screening.

Zavaski and co-investigators examined the frequency of PSA testing according to specialty in 2010 and again in 2012 using the , which collects information about outpatient physician visits, among other data, in the U.S. Their goal was to evaluate the association between the 2012 USPSTF recommendations and changes in PSA testing by specialty among men 50 to 74.

Included in the analysis were all visits for men 50 to 74 to urologists or PCPs for a preventive care visit, excluding visits among men with disorders of the prostate. Overall, there were 27 million eligible visits, 800,000 to urologists and 26.2 million to PCPs.

They calculated that the rate of PSA testing dropped from 36.5% to 16.4% among visits to PCPs (odds ratio 0.43, 95% CI 0.23-0.81, P=0.009) but only from 38.7% to 34.5% among urologist visits (OR 0.34, 95% CI 0.10-1.20, P=0.09). The difference in testing between PCPs and urologists was statistically significant (P<0.001).

"Our findings suggest a differential effect of the 2012 USPSTF recommendations on PSA testing among PCPs versus urologists," the authors wrote. "Such findings likely reflect opposing perceptions among physicians on the benefit of PSA screening, conflicting guidelines (e.g., the American Urological Association recommends joint decision making for men aged 55-69 years), and perhaps differences in patient demographics or expectations. Moving forward, this finding emphasizes the need to continue interdisciplinary dialogue to achieve a broader consensus on prostate cancer screening."

In an editor's note that accompanied the research letter, , from Kaiser Permanente Medical Center, Oakland, Calif., and , at the University of California San Francisco, noted that the study confirms that "there seems to be a continued perception, more firmly held by urologists than by primary care physicians, that the screening is beneficial. Urologists may hold this belief because they have referred more men who request PSA testing or because they have seen more poor outcomes from metastatic prostate cancer."

More data on the rates of metastatic disease and prostate cancer death will clarify the effect of less PSA testing, they added.

A clear reduction in the rate of metastatic prostate cancer with PSA screening argues for continued PSA screening, but a "correction" in the use of PSA testing was needed "since there clearly has been a significant shift to the diagnosis of many prostate cancers that behave more like toothless lions," , from the University of Colorado, Denver, indicated in e-mail correspondence.

"I think the clear message here is that some men benefit and let's find them, not deprive them of the opportunity to be cured," he commented. "In my opinion, the family practice doctors need a simple message and that is, use PSA like any other routine test performed on patients and then discuss when abnormal."

His group has identified a PSA cutoff of 1.5 ng/mL as a reasonable level to determine whether or not further evaluation is needed. Men with a level below this cut point are at little risk of prostate cancer and can safely return for another PSA test in 5 years. Men with a PSA level ≥1.5 ng/mL need further evaluation. Only 30% of men will have a PSA value ≥1.5 ng/mL that requires informed decision-making, eliminating the need to consider more complex measures such as PSA density, PSA velocity, age-specific PSA, and PCA3 urine testing in 70% of screened men, according to Crawford.

Among potential limitations to the study, the authors listed reliance on records of outpatient clinics (and not self reports of PSA testing) and orders for PSA testing (rather than actual testing) and the inability to account for PSA testing outside of physician outpatient visits or PSA testing at a separate visit.

For one educated patient's view of prostate screening and treatment, click here.