Prostate-Specific Antigen Screening: A Patient/Physician Perspective
Author:
Mark Ault, MD
Citation:
Ault M. Prostate-specific antigen screening: a patient/physician perspective. Consultant. 2018;58(2):87-88.
As a primary care physician, I am a staunch believer in evidence-based medicine. But it can be tricky. Screening with the prostate-specific antigen (PSA) blood test, for example, is a moving target. The medical literature and the lay press are replete with recommendations and guidelines about PSA testing, many of which appear vague or contradictory. Let me offer my own perspective as a physician—and a patient.
In its 2012 recommendation statement on prostate cancer screening, the US Preventive Services Task Force (USPSTF) decisively “recommends against PSA-based screening for prostate cancer in all age groups.”1 Other organizations, including the Centers for Disease Control and Prevention, the American Urological Association, the American Cancer Society, and the American College of Physicians, recommend similar although sometimes less-emphatic variations on this theme. Based on thoughtful discussion of the risks and benefits of the PSA test, a not-so-subtle bias toward less testing and more counseling currently appears to exist.
Check the PSA Box, Or Not?
After carefully considering the guidelines, I chose not to get my own PSA level checked, at least not until I began to have symptoms. Admittedly, the symptoms initially were so minor as to be easily ignored. For months, I was able to ascribe them to simple aging and the benign growth of my prostate. I didn’t really consider a slow urine stream or a little hesitancy a symptom any more than I considered my gray hair or my presbyopia a symptom.
Given my options, I did not want medication or surgery to treat what I considered to be manageable symptoms. I certainly didn’t want to deal with the unclear predictive value of the PSA screening test, including the possibility of a prostate biopsy or—heaven forbid—surgery to address the results that an arguably imperfect screening test might yield. I was fearful about the potential complications of incontinence and erectile dysfunction. I recalled too many times when my own patients had been inappropriately relieved by a normal PSA test result, lulled into the belief that this made them immune from prostate cancer. I also have had patients develop anxiety about the prospect of prostate cancer because of a quick check-box test order.
Eventually I did get a PSA test, but not because I had come to a new revelation. During a routine physical examination, my physician checked the PSA box. I’m not certain how that decision came about, and I haven’t asked. Maybe he made more of my symptoms than I did, or maybe he just checked the box. In any case, my PSA level came back at 15.6 ng/mL (reference value, ≤ 4.0 ng/mL). Digital rectal examination (DRE) findings were normal. Urine collected after prostate massage did show inflammatory cells.
Undoubtedly these findings were the result of an infection, I rationalized, and a 2-week course of antibiotics clearly would resolve this abnormality.
But a repeated PSA test result 3 months later was even more elevated at 18 ng/mL. I had now set sail on a course for advanced diagnostic testing. Having exhausted a more conservative approach, I underwent prostate biopsy. My stress level about my own well-being was beginning to escalate. My wife, the only person I shared my plight with, was stoically enduring her own emotional turmoil. I could clearly see the risks and the burdens of a false-positive PSA result. At the same time, I couldn’t avoid the nagging feeling that this really was a true positive.
NEXT: Awaiting the Diagnosis
Awaiting the Diagnosis
In his classic thought experiment, Schrödinger argued that an outside observer cannot know whether a cat placed in an armored container with an explosive is alive or dead, and therefore that cat remains both dead and alive to the outside universe until the box is opened. I find this to be an intriguing metaphysical paradox when applied to the cat model. Applying Schrödinger’s theory to myself as I awaited the results, I both did and did not have cancer simultaneously, and I became consumed by what-ifs. While I prayed that the biopsy would be benign, I strongly suspected this would not be the case. But how much cancer could I have with normal DRE findings, unremarkable ultrasonography findings, and virtually no symptoms?
I was shocked to learn that the prostate biopsy results were strikingly unequivocal: All 12 of the core samples were positive for a highly aggressive cancer, earning a Gleason score of 9 of 10. I had clearly blown past the option of watchful waiting.
I have since begun hormone therapy, and I have had radical prostatectomy. Pathology test results revealed that 80% of my prostate had been engulfed in tumor with no discrete lesions, explaining the discordantly normal physical examination findings and grossly abnormal biopsy findings.
Now, after a 6-month reprieve with an undetectable PSA level, I have since had a recurrence of a rising PSA level.
While I wait for the rest of the story to play out, I am trying to make sense of how best to use the PSA test and how best to apply the guideline strategies to better serve my patients. Anecdotal experience is a slippery slope upon which to establish a generalized policy. I do recognize that my experience is an unusual circumstance, and that most patients with a positive PSA test result will have less-aggressive disease and will not benefit from treatment. I also recognize that had I had a PSA test earlier, I may have had the opportunity to diagnose this potentially lethal disease in time to allow for a cure.
In April 2017, the USPSTF published a revision of its screening recommendation statement, which now recommends “individualized decision-making about screening for prostate cancer after discussion with a clinician, so that each man has an opportunity to understand the potential benefits and harms of screening and to incorporate his values and preferences into his decision.”2 Previous guidelines tended to encourage a conservative approach to PSA testing. Yet my urologist and other health care providers whom I have met along this journey have been appalled that I had not had PSA testing earlier. This current recommendation allows the responsible clinician to have a discussion with the patient that considers the emotional impact of a false-positive result vs the fear of potentially missing a cancer diagnosis.
NEXT: An Informed Approach to PSA Testing
An Informed Approach to PSA Testing
In my practice, I have dichotomized my approach based upon my own N-of-1 experience and buoyed by the latest USPSTF recommendation. If my patient and I would be unwilling to proceed with therapy of any sort based on a positive PSA test result, then the test is deferred. On the other hand, if a positive test result would be pursued, then I order the PSA test—even if the patient is asymptomatic and is fully aware of the test’s inadequacies. I will make a diligent effort to help my patient plan a reasonable course of action in the face of a less than perfect test, realizing the potential for harm that is greater than benefit must be skillfully addressed.
Does this plan follow the recommended guidelines? It does now. And it always has, in the strict sense that all of the guidelines have recommended thoughtful discussion between the patient and physician. Will this result in more liberal use of PSA testing? In my case, it will. I would have had my test months if not years earlier.
Will it make my job more difficult? Quite likely, since the job of pretest counseling will be more arduous, and the rational pursuit of the abnormal test result will be more difficult. But if the role of the test is to not miss cancers like mine, then it is a burden worth shouldering. I don’t believe this makes logical application of the Bayes theorem incorrect. We just need to be more specific about the disease for which we are screening. We are looking for highly aggressive life-limiting tumors that must be found, and we need to cast a wide net. Everything else must be considered background noise.
Medicine is an art, and in this era of cost concerns and less-is-more diagnostics, the physician must truly be an artist, using all of his or her professional training and expertise to help each patient find safe harbor in health maintenance guidelines. It is clearly easy to check a box, but it is our management of the results that will benefit us all.
Mark Ault, MD, is an attending physician in the Division of General Internal Medicine at Cedars-Sinai Medical Center and a professor of clinical medicine at the David Geffen School of Medicine at UCLA in Los Angeles, California.
References:
- US Preventive Services Task Force. Final Recommendation Statement: Prostate Cancer: Screening. https://www.uspreventiveservicestaskforce.org/Page/Document/RecommendationStatementFinal/prostate-cancer-screening. Published May 2012. Accessed January 10, 2018.
- US Preventive Services Task Force. Draft Recommendation Statement: Prostate Cancer: Screening. https://www.uspreventiveservicestaskforce.org/Page/Document/RecommendationStatementDraft/prostate-cancer-screening1. Published April 2017. Accessed January 10, 2018.