To PSA test or not to PSA test: That is the discussion

Steven J. Atlas, MD, MPH

Though it seems Americans don’t agree on much, screening for cancer is an exception. Who wouldn’t support preventing or identifying cancer at an early, more treatable stage, when the alternative is pain, toxic therapies, and a shortened life? That may be why people get confused when news headlines don’t reinforce a “just do it” message. A recent example of the disconnect between public perception and medical evidence is screening for prostate cancer using the prostate-specific antigen (PSA) test. The United States Preventive Services Task Force (USPSTF), a non-governmental expert panel that produces guidelines for primary care providers, proposed new recommendations saying doctors should only order the PSA test for older men after discussing its pros and cons and eliciting preferences for screening.

Screening for prostate cancer with the PSA test: The backstory

To understand the new draft recommendation requires a brief history of this test. Introduced in the 1980s as a way to follow patients already diagnosed with prostate cancer, it began to be used to screen for new cancers. Given that the PSA is an easy blood test to perform, it was quickly adopted — without waiting for evidence that it actually worked. For many years, the USPSTF said there wasn’t enough information to recommend for or against the PSA test.

That changed in 2012 when the USPSTF released a controversial recommendation against screening. It was based in part on a large US study showing no decrease in prostate cancer deaths among men screened using the PSA test. The recommendation also reflected concern about the test causing a surge in prostate cancer diagnoses, many of which were small, low-risk cancers being treated with surgery or radiation — treatments with common side effects.

I was uncomfortable with this “don’t screen” recommendation and am happy about the proposed change. Here’s why: while the US screening trial was negative, another large study in European men showed a small decrease in prostate cancer deaths after more than 10 years of follow-up. Moreover, specialists had devised new strategies to avoid overtreating low-risk cancers.

Having a conversation about screening with the PSA test

I discuss the pros and cons of the PSA test with my patients and ask about their personal preferences for screening. I tell them that while screening can reduce death due to prostate cancer by 20%, the “bang for the buck” is small. It takes screening of over 1,000 men to prevent one death. I also highlight that the benefit of screening is years off, but the risks of treatment — impotence, incontinence, and bowel problems — occur right away.

I also emphasize the PSA test isn’t very accurate. There can be anxiety due to false positive results, meaning further testing shows no cancer. I mention the potential for diagnosing a low-risk cancer where the treatment may be worse than the disease, and that following them closely without treatment may be preferable. How much a man wants to know something like this can differ — some view it as useful information, others see it as an endless source of worry.

Finally, I share my own perspective. As a medical student in the late 1980s learning about the PSA test, my grandfather was dying from prostate cancer. He was an otherwise healthy man who had many good years left, and I wondered if the PSA test could have helped him. Because of this family history, I have decided to have the PSA test. But I’m also unsure what I would do if I didn’t have that history. The small potential for benefit must be weighed versus the risk of false positives or of finding a low-risk tumor that may never cause harm. I can see how two men without risk factors for prostate cancer could make different decisions.

So, I think the USPSTF got it right. This is a decision best made by a well-informed patient in collaboration with his doctor. The challenge in implementing this is practical: the short time I have with each patient. I could save time by simply ordering the test without a discussion. But in my role as health advisor, I need to be able to not only say when I think we should or should not do something, but also when there is a choice. And when there isn’t one right decision for everyone, my patient is the best person to make the choice that’s right for him. I can state my personal preference, but need to highlight why that may not be the right answer for him.

Sources

The US Preventive Services Task Force 2017 Draft Recommendation Statement on Screening for Prostate Cancer: An Invitation to Review and Comment. JAMA, published online April 11, 2017.

Screening for Prostate Cancer: U.S. Preventive Services Task Force Recommendation Statement. Annals of Internal Medicine, August 2008.

Understanding Task Force Recommendations, Screening for Prostate Cancer. The U.S. Preventive Services Task Force, May 2012.

 

Comments:

  1. wayne Ollweiler

    I am agonizing over whether to test or not to test. I have had urologists come down on both sides of this issue. I have yearly checks the old fashioned way and all seems good. However, I am now 58 and my family history includes PC. Father and Grandfather both had PC in their 70’s. Would this indicate that I would most likely follow this pattern?

  2. J. Paul Everett, IE, ret.

    I am 80, and in reasonable health. A year ago my PSA came in at 7.9 AFTER a DRE (see below). The urologist wanted to do an immediate biopsy but I said not before I do a lot of research. Long story short, I have not had the biopsy, my PSA fluctuates between 4.7 and 6.2 now, after seeing a oncology Naturopathic doctor and being put on specific supplements. He believes, from my 10-year progression data, that I likely have a slow growing cancer but that in five years far better treatments will be available, so our goal is to hold it at bay. I’m fine with that.

    Some things I learned: My age-specific PSA being OK is 6.5. Second, way too many men have permanent, nasty side-effects from the invasive exam, referred to in this article. Third, ALWAYS get your PSA blood test taken BEFORE a DRE as the DRE raises the level by 0.4. As stated in this article only 1 out of 1,000 men are saved by the investigation. Five screened die of cancer anyway, five unscreened also die of cancer. Here are some resources.

    http://www.nytimes.com/aponline/2016/09/14/health/ap-eu-med-prostate-cancer.html?_r=0

    http://www.medicinenet.com/prostate_specific_antigen/article.htm

    http://www.nytimes.com/2016/09/15/well/live/helping-patients-make-the-right-decisions.html?em_pos=small&emc=edit_hh_20160916&nl=well&nl_art=5&nlid=8382920&ref=headline&te=1

    http://jnci.oxfordjournals.org/content/97/15/1132.full.pdf

    Effect of DRE before serum PSA level:
    The median change in the serum PSA level for the study group was 0.4 ng./ml. compared to -0.1 ng./ml. for the control cohort (p less than 0.0001).
    J Urol. 1992 Jul;148(1):83-6.

  3. SAFI UR REHMAN

    The disucussion to to PSA or not to PSA test did not relieve the confusion and I guess never will.
    I suggest PSA is useful If persistantly hight , MRI prostate is indicated. If cancer or suspescious lesion is identified, image or U/S guided biopsy should be done.
    The so called “safe cancer” should be followed with MRI and PSA tests. The aggressive cancers should be treated as appropriate.
    The indications and contraindications , risks and complications should be explained to the patients as always.
    The aim should be early detection and treatment as appropriate.

  4. OldHat

    Another anecdote. 82 yr old.
    PSA was 4.2 for a year, then shot up to 12.0. Two docs thought there was some abnormal lumps. An experimental blood test showed a 45% chance of aggressive PCa. Had 12 point biopsy which proved negative, Recommendation to me: don’t take anymore PSA tests.

    sa

  5. N

    Everything should be based on a man’s age group. Prostate cancer in an older individual might not kill him. Due to accelerated cell cycle, prostate cancer in any younger man means aggressive. Any elevated PSA in a younger man MUST be investigated. If no improvement is seen in PSA at six weeks, biopsy should be mandatory.

  6. Robert Bramel

    “Most men will die of other causes…” I’d heard that many times and bought into the idea without really thinking about it. What does “most” mean? 99%? 90%? 60%? 51%? How much risk would a man be willing to take that he WILL die of prostate cancer? PCa is a major killer; it’s number three for men in my age range! I’m currently watch a good friend die a slow, painful death from prostate cancer; it is agonizing!

    So when my PSA reached 4.1, only 0.1 above “normal” I opted for a biopsy, against my urologist’s recommendation. When the results showed I did have prostate cancer, he was, to use his words, humbled. He suggested all the usual options, but when I reminded his that PCa was a major killer, we quickly moved to prostatectomy. I had a robotic prostatectomy a year ago and have never regretted the decision.

  7. Richard

    I am over 70 years old and my urologists NP told me were not doing PSA on me anymore as inconclusive for my BPH situation having had several biopsies and no cancer. Stated also that I would die from something else before would from prostate cancer. I asked then what would happen if cancer detected later he said would be at latter stage then. Very comforting. I have a new primary Doctor who does PSA every year as Doctor said also felt more comfortable doing it than not and I agreed.

  8. Tim Lorsch

    Please explain how these two adjoining sentences in the article can coexist. On the surface, they seem to be radically different.
    1. “while screening can reduce death due to prostate cancer by 20%…,”
    2. “It takes screening of over 1,000 men to prevent one death..”

    • Steven Atlas

      You’re correct – they do seem to be contradictory. But here’s why they aren’t. One refers to relative risk and the other is absolute risk. As an example, cholesterol lowering medicines on average reduce risk of heart attack by 33% (relative risk). If your personal risk of a heart attack is 18% over the next 10 years, a 33% risk reduction means that your risk goes from 36% to 24% – a 12% absolute risk reduction. If your personal risk of a heart attack is 3.6% over the next 10 years, a 33% risk reduction means your risk goes from 3.6% to 2.4% – a 1.2% absolute risk reduction.

      Media reports often cite relative risk – but for an individual, the absolute risk is often more helpful since it takes into account how likely the event is to happen. For more information on this, check out: https://www.healthnewsreview.org/toolkit/tips-for-understanding-studies/absolute-vs-relative-risk/

  9. Rick Thomas

    I have seen discussions on this before. I have to say I fail to understand what the issue for getting a PSA test is. Although I am a prostate cancer “survivor”. But I did not JUST get a PSA reading to determine next steps. When the PSA test came back high, my regular doc referred me to an urologist who checked for infection and other conditions that can cause a high reading; also an ultrasound examination; DRE; and then he gave me a round of antibiotics to totally rule out the infection. Additional PSA testing showed no difference. I was only 59 at the time and age is another factor doctors take into consideration as mentioned in the article. A biopsy was recommended. The biopsy seems to be especially a concern for issues about it causing negative side effects and I have heard of some. But I did it and that came back positive with a Gleason 8 (4+4). A MRI & bone scan were ordered to determine if the cancer had spread. Result was only to the seminal vessel. Based on all factors a prostatectomy was recommended which I did. I have heard from other men whose doctors didn’t follow the above steps and to me, this indicates the experience level of the doctor which makes a huge difference. Now after surgery, the PSA test is used to determine if the cancer is coming back which in my case it did and so I did a round of radiation therapy recently. Again, next treatment depends on the circumstances and the doctor’s experience. I still get PSA tests regularly to check for a reoccurrence. As far as I am concerned there is no reason to not check the PSA after one gets older and realize it is NOT the only factor for a biopsy or treatment.

  10. Juan Carlos Fogarin

    As far as I know, both controls of prostate, are complementary, the “finger old method” and the PSA test.

  11. Mark Kotch

    I believe the real problem is with blind biopsies and not the PSA test. My follow-up MRI revealed what three specialist said was a lot more cancer than actually found by biopsy, or a tumor that has spread from the right lobe to the left lobe of the prostate. I had a GS 7 (4+3) with a PSA of 11.2 when I began treatment. The PSA raised alarm bells, but the biopsy indicated I was T1c. The follow-up MRI found bilateral disease and the DRE also found a hard spot on my prostate. I treated because it was hard to turn a blind eye to numerous adverse risk factors, though i was supposedly T1c.

  12. Tom Abbott

    Why no mention of biopsies after a “high” PSA reading? And if a biopsy showed significant cancer spots, then an MRI would show how far it had reached, and maybe dangerously close to the prostate’s edges. Shouldn’t there have been SOME mention of these diagnostic steps in the article? I had these done after a PSA of 15.2 (I hadn’t had a physical or blood labs done after the 2012 recommendations), and the biopsy and MRI were crucial in determining a dangerous situation. Radiation of the entire prostate followed – with NO complications.

  13. Nancy B

    Thank you for your post Dr. Atlas. I have a question. Can the PSA test or another test differentiate the slow growing cancer from the more aggressive growing cancer so the patient can make a more informed decision of whether or not to treat the prostate cancer? Again, thank you for your time.

    • Steven Atlas

      Great question. The PSA test itself doesn’t do a good job in differentiating slow and fast growing prostate cancers. When the test is extremely high, it may reflect widespread disease. For most, it takes a biopsy to better identifying how aggressive the prostate cancer is. This is the Gleason score. However, even this isn’t definitive. That’s why it is sometimes hard not to treat.

  14. Ashok Vijh

    The PSA test is a preliminary indicator of possible prostate cancer. However, over a period of time if repeat PSA tests are done to establish(1) PSA velocity, (2) PSA density, (3) and, especially the ratio of free to total PSA, the approach can be a powerful predictor of cancer that should be treated.

    Untill we have biomarkers to distinguish as to which cancers are slow growing and harmless and which prostate cancers will kill you, wait and see is a Russian Roulette:this is how P.E. Trudeau( the late Prime Minister of Canada and President Mitterand of France died.

  15. Tim Johnson

    It says in the brief that the PSA is not very accurate. Since I’ve been diagnosed with PC my subsequent PSA checks are measured in ng/ml i.e. Ten to the power of minus 9 ! I’ve had a Robotic Radical Prostatectomy and the regular PSA checks I now have look for an “undetectable” level in my blood test. What would be an accurate measure ? I’m only a layman, but parts per billion seem pretty conclusive to me . Am I missing something?
    Best wishes Tm Johnson UK

  16. Andrew Goldstein

    Let’s discuss how best to educate those health care providers who help patients understand the rapidly evolving knowledge about how best to use PSA test data and the development of newer tests and treatment plans once the best possible diagnosis has been made. Presently, I believe that too many doctors, NPs and PAs are not keeping up with the new data about prostate cancer diagnosis and management, resulting in poor advice to men.

  17. andrew goldstein

    How PSA cancer screening with its inadequate specificity but good sensitivity can be wrong for some men escapes me. Isn’t the question of the health care provider’s skills an important part of getting the maximum value from serial PSA data while minimizing unnecessary, invasive treatments? Men get only one shot at curative treatment for PCa that requires treatment. There are many more tests now available that help men make the right treatment decisions. But first, men need clear and up to date guidance from their doctor.

    • Steven Atlas

      False positive are only one problem with the PSA test. Probably more important is that the PSA test can identify cancers that will never cause harm. Yes, not all prostate cancer is deadly. It is estimated that 30-40% may be so slow growing that they may never end up causing trouble. However, almost all men diagnosed are treated – and those treatments can cause harm – impotence, incontinence, bowel problems. So the evidence does not support what you say – despite your intuitive argument. For more detail, take a look at the USPSTF document.

      • Tom Abbott

        Why no mention of biopsies after a “high” PSA reading? And if a biopsy showed significant cancer spots, then an MRI would show how far it had reached, and maybe dangerously close to the prostate’s edges. Shouldn’t there have been SOME mention of these diagnostic steps in the article? I had these done after a PSA of 15.2 (I hadn’t had a physical or blood labs done after the 2012 recommendations), and the biopsy and MRI were crucial in determining a dangerous situation. Radiation of the entire prostate followed – with NO complications.

  18. Michael Baca-Atlas

    Nice overview. It’s important to note differences in mortality by race. North Carolina has significantly higher mortality in AA patients. May be multifactorial but I make a point to mention this for my AA patients or who have extensive fam hx.

  19. Bjorn Tore Hammer Engelstad

    In Norway a PSA test are offered to all men over 50 y . old , as a part of the yearly health check at your GP , free of charge . My GP has informed me that the test has it weakness, but I prefer a PSA test instead of the old practice where the doctor asked you to bend over and you got a finger in your anus for a prostate check . My two Medical Doctors have both told me , that most men over 70 y. old will get prostate cancer , but they will live with , and die of other causes when you reach 70 years .For the records . Prostate cancer are still the number one killer , out of all types of cancer , for men in Norway .

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