PSA at 40?

PSA at 40?

Prostate Specific Antigen (PSA) is a widely-used screening test for prostate cancer. Unfortunately these tests cause a lot anguish: an elevated PSA doesn’t usually mean prostate cancer (only 25-30 percent of cases with elevated PSAs are prostate cancer), but it often means a biopsy and a lot of angst.

According to the National Cancer Institute:

Using the PSA test to screen men for prostate cancer is controversial because it is not yet known if this test actually saves lives. Moreover, it is not clear if the benefits of PSA screening outweigh the risks of follow-up diagnostic tests and cancer treatments. For example, the PSA test may detect small cancers that would never become life threatening. This situation, called overdiagnosis, puts men at risk for complications from unnecessary treatment such as surgery or radiation.

So I was a little surprised to read that the authors of a new study are advocating starting PSA testing even earlier: at age 40 rather than age 50. It’s counterintuitive, but the reasoning is that if a patient has a longer baseline it will be easier to tell from the PSA whether they in fact have cancer. For example, as I read in the Wall Street Journal (Beginning Prostate-Cancer Screening At Age 40 Holds Benefits, New Data Show):

[A] 40-year-old man who has a PSA of 0.8 at 40 and then a score of 2 a few years later likely is at high risk for aggressive cancer. But if he has a score of 2 and no prior PSA test, he likely would be told he’s at low risk. By the time his PSA score reaches 4 and doctors decide to intervene, it might be too late to save him.

Meanwhile a 50-year-old man with a PSA of 4 likely will be told he needs a biopsy. However, if that man at the age of 40 had a PSA of 2, the 10-year trend suggests he likely doesn’t have cancer or at least not an aggressive cancer.

“It’s the same threshold of 4,” says Dr. Carter. “But the two people got to that threshold at much different rates. I see this as a way to decrease the men who have biopsies and identify the men with lethal disease.”

The logic sounds good, but it makes me nervous. I’m turning 40 next year and I think I’ll wait till I turn 50 to start testing. (I’ll see what my doc thinks before deciding.) I don’t have any of the prostate cancer risk factors and I’m as scared of having a false positive as I am of prostate cancer itself. In 10 years, when I’m 50 maybe there will be a better test and it won’t matter that I don’t have baseline PSA data.

November 7, 2006

9 thoughts on “PSA at 40?”

  1. Several concerns about starting PSA screening earlier:

    1. PSA testing is already plagued by high rate of “false positive” tests, leading to unnecesary additional invasive testing (eg., biopsy). The rate of “false positives” for any test increases when you test a group (eg., younger men) in which the disease for which you are screening is found at a lower rate. Therefore, if you start testing PSA’s in the 40 -50 y.o. age range, you will likely increase the rate of false positives.

    2. Who is pushing this? The advent of PSA screening has been a boon for the urologist and all related aspects of the healthcare industry, despite very ambigious impact on patient health. Studies will often have biases (often hidden)that represent the desires of the specialty group, and/or other interests who want something to become “standard of care”.

  2. PSA is an excellent screening test. It is not perfect, but it is very good and your own personal beliefs regarding this test and PSA anxiety etc are not relevant. As a physician, you have an obligation to discuss the role of PSA screening and its pros and cons with your patients and then you and they can decide when and whether to start screening.

  3. I am not sure that it would be accurate to describe PSA testing in general as “excellent”, given its limitations. The issue at hand is whether you take a test with known limitations, largely related to high rate of “false positives” when applied to a higher risk population (eg., those age >50 or African American patients >45 or those with family history), and recommend it in a group with a significantly lower prevelance of the disease (eg., those age 40-50). As I stated in my original comment, this approach is likely to increase unnecesary invasive testing more than it will reduce morbidity and mortality. I personally think our energies are better spent refining the use of PSA in the >50 population with more sophisticated measurements (re., measuring free fraction etc…).

    As per this quote from the American Cancer Society:

    “No major scientific or medical organizations, including the American Cancer Society (ACS), American Urological Association (AUA), US Preventive Services Task Force (USPSTF), American College of Physicians (ACP), National Cancer Institute (NCI), American Academy of Family Physicians (AAFP), and American College of Preventive Medicine (ACPM) support routine testing for prostate cancer at this time. The USPSTF has concluded that studies completed so far do not provide enough evidence to know whether the benefits of testing for early prostate cancer outweigh the disadvantages.”

    The ACS does recommend having a “discussion” with patients. This is what I do, and frankly, I end up sending PSA’s on most patients.

    P.S. I think a patient’s “anxiety” regarding a screening test is entirely relevant. Many patient’s opt to “not know” and, if done under “informed refusal” that is certainly acceptable (and understandable).

  4. Pingback: Why not lower the recommended mammogram age to 30? or 20? | Health Blog
  5. Hey! I know this is sort of off-topic but I had to ask. Does operating a well-established website like yours take a lot of work? I’m brand new to writing a blog but I do write in my diary everyday. I’d like to start a blog so I can share my personal experience and views online. Please let me know if you have any suggestions or tips for brand new aspiring bloggers. Thankyou!

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