by ecancer reporter Janet Fricker

The debate about  prostate-specific antigen (PSA) screening for prostate cancer, continued in a series of four  opinion pieces  published in the December 28 issue of JAMA.  A report on the first commentary by Roger Chou and  Michael LeFevre  was published in eCancer News on 6 January - here we report on the three additional commentaries.

The debate initially kicked off in October 2011 when the US Preventive Services Task Force (USPSTF) issued a new draft recommendation following an updated review of the evidence that lowered the PSA screening rating from an I (where evidence is considered “inconclusive”) to a D (where “The USPSTF recommends against the service.”)  

The USPSTF concluded there to be moderate certainty that the harms of PSA-based screening for prostate cancer outweighed the benefits. “The task force now proposes discouraging PSA screening among men who are free of symptoms suspicious for prostate cancer,” concluded the USPSTF authors.

In the first JAMA commentary ¹  Robert Volk  from the University of Texas M.D. Anderson Cancer Center in Houston and Andrew Wolf  from the University of Virginia School of Medicine in Charlottesville, write that the authors of the USPSTF deserve credit for “sharpening the focus” on the risks and harms of prostate cancer screening.

But by recommending against prostate cancer screening altogether the task force, they write, discounts the evidence supporting the effectiveness of screening and disregards the great value that many men place on averting a cancer death.

It would have been better, Volk and Wolf argue,  to award prostate cancer screening a grade C recommendation, which  while recommending  against routine screening,  allows for individualized decision making. This would allow men to be informed of the potential benefits and harms of screening and to decide in partnership with their physicians whether to proceed.

Furthermore, a grade C recommendation would put the  USPSTF in line with other medical organizations,  including the American Cancer Society and the American Urological Association, in recommending against routine screening but promoting actively engaging men in the decision process.

The USPSTF recommendations “miss the mark” write  David Miller and Brent Hollenbeck, both from the Department of Urology at the University of Michigan, Ann Arbor,  in the second commentary ².

Over the past two decades, there has been a significant decline in prostate cancer-specific mortality in the US, which is difficult to explain without accepting  the benefit of early detection strategies built around PSA screening.  “However, this advance apparently was barely recognized in the deliberations and communications from the task force,” write the authors.

The task force, add the authors  is essentially "relegating some men to an avoidable death from prostate cancer, including the morbidity associated with metastatic disease.

“Clinicians must preserve the ability to detect aggressive prostate cancer while these tumors are still at an early stage," they write. "At the present time, PSA screening is the best tool available to achieve this objective, even if it means some men may experience morbidity and mortality associated with diagnosis and treatment."

Further efforts, they add, should be directed towards decreasing treatment-related morbidity through the judicious use of less invasive new technologies , thereby reducing complications and functional impairment.

In the third commentary Jeri Kim and John Davis ³, both from the University of Texas M.D. Anderson Cancer Center,   write that in the face of the lengthy natural history of prostate cancer, the elimination of PSA screening would be  premature .  “Until each man’s risk for prostate cancer can be individually assessed (as it will be in future) a new model is needed for managing the disease in PSA-screened men,” write the authors.

One possible  model, they suggest,  would assign patients with low-volume, low grade disease to active monitoring and those with high-grade aggressive tumours to selective treatments. Some low-risk patients with tumours sensitive to the 5-alpha reductase inhibitors finasteride and duasteride could be identified (from predictive markers in development) and  also offered treatment.

Further guidance, add Kim and Davis,  will become available when the results from  two large randomised trials comparing active surveillance with active treatment - the Prostate Cancer Intervention Versus Observation Trial and the Prostate Testing for Cancer and Treatment Trial are published.

References

1. R J Volk, A Wolf.  Grading the New US Preventive Services Task Force Prostate Cancer Screening Recommendation.     JAMA 2011, 306:2715-2716.
2. DC Miller, B K Hollenbeck.  Missing the Mark on Prostate-Specific Antigen Screening. JAMA 2011, 306: 2719-2720
3. J Kim, J W Davis. Prostate Cancer Screening-Time to Abandon One-Size Fits-All Approach? JAMA 2011;306:2717-2718