Evaluating New Guidelines for PSA Screening

Today’s guest article is written by Mark Bricca, ND, LAc. Mark practices as a clinician at the Mederi Centre for Healing in Ashland, Oregon.

For years, “routine” PSA screening was considered a standard part of prudent, preventive medicine, and surveillance was commonly encouraged by doctors for men beginning in their 50’s. About a year ago, in May of 2012, the U.S. Preventive Services Task Force (USPSTF) came out with a new recommendation—namely that all men, regardless of their age, should not regularly have PSA screening tests performed unless they are determined to be at increased risk for prostate cancer. What changed, and why the new guidelines? Let’s see if we can understand this whole situation a little better!

In order to do that, we first need to take a step back, lest we lose the forest for the trees. We must consider a few basic assumptions that have historically been made with respect to cancer prevention and treatment—namely that prostate cancer (or any type of cancer for that matter) is a local phenomenon until it’s metastasized, or spread, and that early detection always leads to better, more effective, and less harmful treatments. On all counts, astute physicians and researchers are now questioning these fundamental tenets, and for good reason. It’s becoming well established that even in seemingly early, pre-invasive cancers, such as breast ductal carcinoma in situ, it’s often possible to locate cancer stem cells in patients’ bone marrow; thus, it’s clear that even very early cancers, including nascent prostate cancers, should truly be considered systemically as opposed to locally when it comes both to prevention and treatment.

The catch is that, in such early situations, it’s very unlikely that a screening PSA test would detect any abnormality. This is called a “false negative” result, meaning that something is, indeed, abnormal, but the screening test failed to pick it up. And, to further confuse the matter, we also need to bear in mind that a PSA level can register as elevated for a host of reasons that are completely unrelated to cancer, including benign prostatic hypertrophy (BPH) and prostate inflammation (even mild inflammation can cause PSA to elevate). This kind of elevation would lead to a “false positive” screening result, meaning that we could be concerned about the possibility of prostate cancer even when none is present. In such instances, historically speaking, many men with even modestly elevated PSA levels following screening were subjected to prostate biopsies. Has this practice been helpful?

Based on two recent, well-publicized cancer screening trials, the USPSTF estimates that, for every 1,000 men screened by routine PSA testing, 1 prostate cancer-related death will be prevented. While there has been some controversy regarding some of the methodology of these two trials, I think the message is still clear: namely that PSA screening is not the be-all-end-all that we once thought it to be. Moreover, we now have enough of a track record with this type of screening to comprehend the significant harm we can do (and have done) to many men who have been subjected to biopsies of their prostate glands following modest PSA elevations on screening. It really does beg the question: Are we harming more men than we’re helping?

As reported in Medscape Medical News on March 11, 2010, the discoverer of PSA, Dr. Richard Ablin, clearly thinks we’ve strayed down the wrong path, and that these new guidelines represent an awakening:

“[PSA testing] should absolutely not be deployed to screen the entire population of men over the age of 50, the outcome pushed by those who stand to profit.  Drug companies continue peddling the tests and advocacy groups push ‘prostate cancer awareness’ by encouraging men to get screened. I never dreamt that my discovery 4 decades ago would lead to such a profit-driven public health disaster. The medical community must confront reality and stop the inappropriate use of PSA screening. Doing so would save billions of dollars and rescue millions of men from unnecessary, debilitating treatment.”

It’s common for men diagnosed via PSA screening with early, low malignant potential prostate cancer to be treated aggressively with some combination of radical surgery (prostatectomy), radiation, and androgen (testosterone) deprivation therapy. The trouble is that, as noted by the USPSTF, “adequate evidence shows that up to 5 in 1,000 men will die within 1 month of prostate cancer surgery and between 10 and 70 men will have serious complications.” So, taking into account the aforementioned fact that routine PSA screening appears to save approximately 1 life for every 1,000 men who are screened, it seems we have to pay an unacceptably high price in return for this benefit. We need a better way!

And we also must really let it sink in that the majority of prostate cancers are typically very slow growing, non-aggressive, and non-threatening. Consider the fact that about 80% of men aged 70-79 may be found to have prostate cancer on autopsy, and yet a comparatively small percentage of men in that age bracket will die of anything related to prostate cancer (a great many more will die from cardiovascular diseases). The take-home message here is that prostate cancer most often grows slowly when it’s present—usually over decades—and it’s typically neither extremely aggressive nor invasive, which means that we’ve been causing needless harm in the form of treatment related adverse effects to a large number of men in recent years who we’ve subjected to fairly heroic interventions in the name of early intervention. This is how statistics get skewed—because we can say that we’re “curing” more prostate cancers… until we stop to reflect on the preponderance of treated cancers that never would’ve caused any morbidity and consider the harm that various conventional treatments can, and do, cause.

There is a better way, and it centers on highly individualized prevention, assessment, and treatment, as opposed to more “blanket” screening guidelines. I’m not saying that we should completely throw the proverbial baby out with the bathwater and never run another PSA test, and I do, at times, order it for screening purposes when I need to inquire more deeply into symptoms a man is having. It’s also important to note that an elevated PSA result can absolutely warrant further inquiry and investigation, which is why the American Urological Association (AUA) still advocates that men between the ages of 55 and 69 should discuss the option of PSA screening with their doctors (though some might argue that the AUA’s recommendation is biased, since urologists stand to profit the most from PSA screening and subsequent treatments).

It’s uncommon for men younger than 50 years of age to be diagnosed with prostate cancer, which is why screening has only been recommended for men in that demographic who are known to be at high risk (men who have a first-degree relative that was diagnosed with prostate cancer at a young age, for example). Furthermore, and because the majority of prostate cancers are relatively benign, it would be silly to screen (and subsequently treat) men over the age of 70 for cancers that, far more often than not, will cause them less harm than the treatments they would receive. In the demographic of men aged 55 to 69 who are either at higher risk or who are having lower urinary tract symptoms, PSA testing is still a reasonable assessment tool, but its value as well as its limitations both need to be understood and it needs to be held in a larger context.

Rather than proceeding from elevated PSA directly to biopsy (except in the rare, concerning case that clearly warrants such action, as when the PSA is extremely elevated), we need to slow down and really think. Like Sherlock Holmes, it’s incumbent upon us to consider all the available facts when we discover an elevated PSA result, including a man’s personal and family history, present symptoms, physical exam findings (including palpation of the prostate gland via digital rectal exam), risk factors for prostate cancer, prior PSA results (if those are available, to establish a trend and rate of increase), and the percent free PSA (when greater than 25%, the risk of prostate cancer is as low as 5-9%). If, based on this initial inquiry, there’s reason for concern, then a special urine test called the “urinary prostate cancer gene 3,” or PCA3 test, should be run. Non-invasive and easily performed, it’s highly over-expressed (66-fold) in greater than 95% of prostate cancer cells compared to normal or merely hypertrophied prostate cells, which makes it a much more specific test than PSA alone. Therefore, the PCA3 assay, when used appropriately and in the context of a thorough, individualized assessment, is another very useful tool that we might employ before we put the cart before the horse, so to speak, and rush to perform an invasive biopsy.

So, in a proverbial nutshell and to summarize, let’s bear in mind these few crucial points as we consider appropriate prostate cancer screening: First, we need to recall that all cancers, including cancers of the prostate, should truly be understood as systemic, and not merely local, phenomena. Second, we can empower ourselves with the knowledge that, almost always, these cancers are relatively benign and slow growing, usually advancing over decades (when they do advance, which they often don’t), which means that our best investment is not going to be in screening but rather in first cultivating healthy lifestyle and dietary habits and then using well-chosen, individually-tailored supplements that have the greatest preventive capacity. And, lastly, once these things are considered, let’s remember that PSA is still a useful “tool” in our overall assessment toolbox, but let’s also think carefully and critically about how, and when, we utilize it, and let’s not give it more weight and diagnostic credibility than it can statistically bear or than it really deserves.

We started with such a seemingly simple question… and down the “rabbit hole” we went!  That’s what I love about medicine: It’s as much art as it is science, and, often, the answers are more nuanced than they are neat and tidy. They’re as varied as each person is, which is why I enjoy spending so much time with each of my patients and getting to know them so well. Only then can these kinds of decisions be made appropriately, rather than on a “mass-screening” basis. This, I believe, is how good medicine ought to be practiced.