In May, the US Preventive Services Task Force (USPSF) released a final recommendation on prostate cancer screening that was published in the Journal of the American Medical Association. We discussed the updated recommendations with USPSTF Vice-Chairperson Alex H. Krist, MD, MPH, and prostate cancer specialist David F. Penson, MD, MPH. Dr. Krist is Professor of Family Medicine at Virginia Commonwealth University (VCU), Richmond, Virginia, and director of community engaged research for VCU’s Center for Clinical and Translational Research. He is also co-director of the Virginia Ambulatory Care Outcomes Research Network (ACORN), in Richmond. Dr. Penson is Paul V. Hamilton, MD and Virginia E. Howd Chair in Urologic Oncology, and Professor and Chair of Urologic Surgery and Medicine, at Vanderbilt University Medical Center, Nashville, Tenn.
—Interviewed by Anna Azvolinsky, PhD
Cancer Network: First, Dr. Krist, can you tell us when the last update to the prostate cancer screening recommendation was made, prior to this new one?
Dr. Krist: The US Preventive Services Task Force is recommending that, for men 55 to 69 years of age, the decision of whether to be screened for prostate cancer with a PSA [prostate-specific antigen] blood test should be an individual one. We want men who are considering screening to understand the benefits, understand the potential harms, have a discussion with their doctor, and then incorporate their values and customs [into the decision of] whether screening is right for them.
We are recommending that [because] we know from the evidence that the few men who decide to be screened will benefit; they may not die of prostate cancer or get metastatic disease. But we also know that many men might [experience] harms from prostate cancer screening. And then the other part of our recommendation is that we are recommending against routinely screening men for prostate cancer who are 70 or older. Men who are concerned and over the age of 70 should always talk with their doctor about what is right for them.
Cancer Network: And how is this new recommendation different from the prior update?
Dr. Krist: Back in 2012, we gave what we call a “D” recommendation, [meaning] we were recommending against routine screening for all men. The basis for that was, in looking at the evidence we had at the time, the benefits of screening did not seem to outweigh the harms. Yet since 2012 when we made that recommendation, we’ve had longer follow-up on several of the key studies that have shown us a few more men would benefit from screening—and that led us to recommend the shared or individualized decision for men, depending on their preferences and values.
Cancer Network: What is the evidence that you and the other Task Force members used to make the recommendation on PSA testing?
Dr. Krist: Whenever we are making a recommendation, we try to look at all of the evidence. We do a systematic review and look at all of the major studies. For prostate cancer screening, three very large trials dominate the evidence. There was a trial done in several European countries, there was a trial done in the US called PLCO [the Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial], and then there was a large trial done in the United Kingdom called CAP [the Cluster Randomized Trial of PSA Testing for Prostate Cancer].
Those three trials had a big influence, but we also looked at the benefits and harms of treatment, [and] changing patterns in how men are treated. Three key pieces of evidence led us to the new recommendation. The first was that, with the follow-up of the European trial, we saw that a few more men who opted to be screened for prostate cancer would not die from prostate cancer. We also saw that 3 out of 1,000 men screened don’t get metastatic prostate cancer. And those two elements gave us [increased] confidence that more men could benefit from screening.
The other thing that we saw was changing practice patterns. In the United States, men with low-grade prostate cancer can opt for surgery, radiation, or something called active surveillance or active management, where [clinicians] watch their cancer and [men] might wait and defer treatment. In 2012, only about 10% of men with active cancer had active surveillance for their early-stage prostate cancer, and now it is up to about 40%—and that has the potential to reduce the harms of screening. So that combination of the practice patterns we saw, and the extended follow-up from the European trial, and some newer evidence told us that we might be able to minimize some of the harms of overdiagnosis and false-positives and some of the treatment harms. [That] gave us a little bit more confidence that some men may benefit, depending on how their [clinical] values are and how worried they are about prostate cancer, compared to the harms.
Cancer Network: Dr. Penson, as someone who treats patients with prostate cancer, what is your perspective on these updated recommendations? How did you interpret and utilize the prior Task Force recommendations, and how do you plan to use these updated ones?
Dr. Penson: I think we need to focus on the new recommendations because that is where we are right now. I have to say that I really applaud the Task Force for…being so thoughtful in reviewing the new evidence and changing the prior recommendations. As Dr. Krist alluded to, there are real benefits and harms to prostate cancer screening, and it is not a simple decision.
So in the end, this new recommendation of a “C” grade, which leads to individualized decision making, is really a step forward. This brings the USPSTF recommendation into alignment with the recommendations of other organizations, for example, the American Cancer Society, the American Urological Association, and others—all of which recommend, not mass screening, which is a mistake that a lot of people make—[but] shared decision making, and helping men make an individualized and informed decision about whether they would like to undergo testing.
The other point worth mentioning that Dr. Krist pointed out is the recommendation for men age 70 and over. As a general rule, that recommendation against screening is generally reasonable; however, as he also alluded to, in clinical practice, sometimes you see men 70 or older who are concerned about prostate cancer and are really quite healthy. So I think that as a general rule, if someone is age 70 and older and is very concerned and they have more than a 10-year life expectancy, it is very reasonable to discuss prostate cancer screening and let [the patient] make an informed decision. But as I said, 70 years and older is likely a generally good cut-off age for when to start thinking about not even offering screening. I think the Task Force is very thoughtful in that regard, and that this recommendation will have a positive clinical impact.
I also want to take a moment to commend the Task Force for highlighting something that often gets lost in the discussion—and that is that all of these recommendations apply to men who are at normal risk for prostate cancer, [but] there are subgroups of men at higher risk: men who have a strong family history of prostate cancer and men who are African American. The studies do not [address] these subgroups [well], and what the Task Force did was to point out that there is a need for more and better research into these higher-risk populations, so we can start to make thoughtful recommendations for screening, one way or the other, for these subgroups of men.
Cancer Network: Dr. Krist, lastly, what is next for the Task Force? Are there additional questions you and your colleagues are addressing with respect to prostate cancer screening in general or certain subgroups of men?
Dr. Krist: The Task Force is always watching the evidence, and certainly as new evidence emerges we revisit and update our recommendations. So, we’ll be paying attention to that for prostate cancer. As Dr. Penson mentioned, we have these knowledge gaps on African-American men and men with a strong family history, so we are calling for more evidence and more studies. Part of our mission and what we do is, we …report to Congress, and Congress [in turn] uses that report to stimulate research from the NIH [National Institutes of Health] to fill these evidence gaps. I think that is a very important next step. The Task Force doesn’t do the research itself; we evaluate the evidence. But now is a good time…for trying to improve how we treat prostate cancer and how we can minimize the harms…[associated] with prostate cancer screening.
Cancer Network: Is there anything else that you would like clinicians and patients to understand about the prostate cancer screening decision?
Dr. Krist: The one thing I would reiterate that Dr. Penson mentioned is that screening for prostate cancer is a complex decision for patients, and its complex for clinicians. Thinking about the potential outcomes, both good and bad around screening, beforehand is very important. A lot of times patients say to me, ‘Gee, doc, it’s just a blood test. Why should I not get it?’ But really understanding both the positives and the negatives [of screening] is important before going down that pathway.