THE "NEW" PROSTATE CANCER INFOLINK

A new and potentially controversial article in Urology (the “Gold Journal”) has just suggested that regular, mass, population-based screening of men for risk of prostate cancer every 12 to 18 months remains a good idea.

The full text of this paper by Alpert is available on line (along with editorial commentary by Qureshi et al.). Thus, interested readers can review the article for themselves, but we do recommend that they also read the editorial commentary (and Dr. Alpert’s response to that comment) at the end of the paper.

Alpert’s paper is based on data from > 400,000 men aged < 80 years who had no personal history of prostate cancer, and who had PSA tests carried out in the Kaiser Permanente Northern California health system between 1998 and 2002. Dr. Alpert categorized these patients into 42 different subgroups and, after conducting a sophisticated but retrospective analysis of all the available data, came to the following series of conclusions:

• Annual PSA testing (i.e., “screening”) “is highly beneficial, reducing prostate cancer deaths by 64% for men aged 55-74 years, and reducing all-cause mortality in this group by 24%.”
• “No benefit was found for men under age 55.”
• “When combined with active surveillance to prevent overtreatment, these data lend support for yearly population-based PSA screening for prostate cancer for men aged 55-74 who are in good health.”

Your sitemaster has some very serious reservations about this paper for a whole spectrum of reasons — not least that the men who were having PSA tests in this study are hardly a random sample of the men whose health was being covered by the Kaiser Permanente Northern California health system over that 5-year time frame. Rather, they were men who had PSA tests for one of three reasons:

• They had a set of symptoms that had taken them to their primary care physician’s office and which led to them being given a PSA test as part of a standard work-up to diagnose their problem.
• They had self-elected to go and have a test for risk of prostate cancer for any one of all sort of possible reasons.
• They were given a PSA test (knowingly or unknowingly) as part of an annual health check.

The fact that these data come from 1998 to 2002 is also relevant. Do the same data from 2008 to 2012 show the same types of result?

As the editorial commentators are careful to point out, we have moved far beyond the point when the primary issue was whether we could identify some prostate cancer in a man’s prostate and then treat him (which was what urologists in California would have been trying to do in 1998 to 2002). What good urologists (and good primary care physicians) are trying to do today is categorize patients into a series of groups, as follows:

• Men who are at minimal risk for clinically significant prostate cancer and (for one of a series of reasons) probably don’t  need to have a biopsy at all
• Men who are at potential risk for clinically significant prostate cancer and probably should have a biopsy of some type in order to clarify that risk level so that they can be managed appropriately
• Men who are clearly at risk for clinically significant prostate cancer and who should definitely be biopsied so that their risk level can be confirmed and they can be managed accordingly

This is a radically different set of objectives from those in place in 1998 to 2002, and so to a considerable extent the data on which Alpert’s paper is based could be highly misleading.

We have said this a thousand times before, but it bears stating again:

We are not dealing here with a black vs. white scenario. Your sitemaster’s risk for clinically prostate cancer (as just one example) is apparently very different from that of many regular readers of this column. In seeking to determine whether any one particular man has clinically significant prostate cancer, we know that the PSA test is little more than a blunt hammer. It is good for telling very roughly whether large groups of men are at a particular level of risk, but it is near to useless at telling whether a particular individual is at risk. Alpert’s own data confirm this because they show that, as previously quoted, “No benefit was found for men under age 55.” But there are men of < 55 years of age diagnosed with prostate cancer every day of the year, and many of those men can have relatively aggressive forms of clinically significant prostate cancer.

No one has ever said that the PSA test is not one of a number of useful tools in making an initial assessment of whether a man might be wise to have other tests to help to decide whether he is at risk for clinically significant prostate cancer. It is. The discussion has always been about whether anyone could produce prospective data from a well-conducted, randomized clinical trial to show that a standardized form of PSA screening could prove that this form of "screening" could actually reduce risk for prostate cancer-specific or overall mortality. The only trial that has ever shown this, as far as your sitemaster is competent to tell, has been the Swedish arm of the ERSPC trial, conducted exclusively in the city of Göteborg at a time when almost none of the participants had ever had a PSA test for any reason. Unsurprisingly, in this particular case, use of the PSA test in this scenario identified a significant number of men with no symptoms of prostate cancer but who had previously undiagnosed, aggressive forms of the disease.

We badly need to get beyond the simplistic discussion of whether PSA screening "works" or "doesn't work". The two new questions that we need to answer are these:

• How do we get better at finding aggressive forms of prostate cancer that need to be treated early, while they can still be cured?
• How do we get better at not wasting everyone’s time diagnosing forms of prostate cancer that will never be clinically significant?

Somewhere in between those two extremes, there will always be a bunch of men who do get diagnosed with prostate cancer that is not necessarily high risk in nature, and who will always have to make some hard decisions about how they want to manage such conditions in concert with their doctors. This can only ever be done through careful discussions between the individual patient and his physician(s), which is at the heart of shared decision-making.

Filed under: Diagnosis, Living with Prostate Cancer, Management, Risk | Tagged: Management, PSA, risk, screening, testing |