A potential new model for prostate cancer screening?


A highly influential group of senior urologists have come together to propose a new model as a methodology for screening men for risk of prostate cancer.

The new model proposed by Crawford et al. (available as a free full text article in the journal Urology) seems to have considerable similarity to a model previously recommended by the prostate cancer specialty group at Memorial Sloan-Kettering Cancer Center (MSKCC) … and one of the authors listed is James Eastham from MSKCC.

Basically, Crawford et al. propose a model that is based on the following key presumptions and criteria:

  • Primary care physicians have become confused by messages about PSA testing, specifically including things like PSA velocity, age-specific PSA, percent free PSA, PSA density, and PSA cutoffs of 1, 1.5, 2.5, and 4 ng/ml.
  • Most primary care physicians don’t have the time or the knowledge to hold a detailed discussion of the pros and cons of PSA testing with individual patients at a routine office visit, but primary care physicians order about 90 percent of all initial PSA tests for risk of prostate cancer.
  • PSA testing for risk of prostate cancer is appropriate for any man with a 10-year life expectancy.
  • Detailed PSA data on > 500,000 men from a respected reference laboratory show that, among men aged between 45 and 70 years of age, about 70 percent have a PSA level of < 1.5 ng/ml.
  • Men with a PSA level of < 1.5 ng/ml are at a very low risk for development of prostate cancer (and high-risk prostate cancer in particular) within the next 4 to 5 years
  • A key goal should be “to avoid [unnecessary] PSA tests in men who would have little to no gain by focusing on age and health.”

So the new model being proposed by Crawford et al. goes like this:

  • Men with a 10-year life expectancy making a normal “healthy patient” office visit to a primary care physician should get a PSA test as part of a normal panel of blood tests (if they haven’t had a PSA test in the preceding 5 years; see below).
  • Men with a PSA level of < 1.5 ng/ml and no sign of risk for prostate cancer on a rectal exam (if a digital rectal exam has been administered) should be advised that their PSA level is normal and that they won’t need another PSA test for 5 years.
  • Men with a PSA level of ≥ 1.5 ng/ml and/or any sign of risk for prostate cancer on a rectal exam (if a digital rectal exam has been administered) should then have an informed discussion about the meaning of such a PSA level and/or finding from the rectal exam and be referred to a urologist for additional testing if they wish to have such a referral or if the primary care physician considers this to be essential.
  • Men who are referred to a urologist would be evaluated for all potential causes of the elevated PSA level, including benign prostatic hyperplasia (BPH), prostatitis, and prostate cancer.
  • If there appears to be a risk for prostate cancer, then other tests can also be administered, including tests such as the Prostate Health Index or phi test, the 4KScore test, the PCA3 test, and/or the SelectMDX test, to identify men whose risk for clinically significant prostate cancer  seems to be real.
  • If the risk appears to be low after re-evaluation by the urologist and the appropriate use of such a test or tests, the patient would be referred back to his primary care physician with a recommendation for a repeat PSA test in 1 year.
  • If the risk appears to be high after such a test or test, the urologist and the patient should consider a TRUS biopsy.

Now let us be clear that this is a model that would be considered to be highly appropriate today by a wide range of urologists and many members of the patient advocacy community too. The question is going to be whether it is a model that is thought to be suitable by members of the primary care community and its organizational representatives (the American Academy of Family Physicians, the American Society for Internal Medicine, etc.) and the representatives of the epidemiology community (e.g., the U.S. Preventive Services Task Force).

We see two potential problems:

  • There are no data from any prospective studies that we are aware of that actually demonstrate the value of such a screening model.
  • There is no specific recommendation about when such testing should be initiated.
  • There is no mention of active surveillance as a potential first-line management strategy for patients found to have low-risk prostate cancer after a prostate biopsy.

This does not mean that the model is a bad idea. It simply means that how useful it is is untested, and will be highly dependent on how well primary care physicians comply with such a model and how well urologists conform to it.

While The “New” Prostate Cancer InfoLink considers this to be a model worthy of extensive discussion — to involve the primary care community and the patient advocacy community as well as the urology community — we would feel that there are some additional, very clear objectives that need to be built into the model, starting with these two:

  • A second key goal should be optimize the early diagnosis of clinically significant prostate cancer — especially among men who are known to  be at higher than average risk of this disorder.
  • A third key goal should be to minimize risk for unnecessary over-treatment of men initially diagnosed with low-risk, non-lethal forms of prostate cancer that are unlikely to metastasize.

 

 

5 Responses

  1. This is a disappointing article because it represents opinions without any data to demonstrate its consequences, both good and bad. It is similar to the recommendations made around 1990 when PSA was being promoted as men’s savior and enthusiasm for it has resulted in over 1,000,000 men getting a treatment they never needed. That promotion occurred in the absence of the data needed to justify it. Also, it seems like it is a case of the “cart before the horse”; have men get the test without any understanding or input of the pros and cons and only if the test is above 1.5 ng/ml will they get that discussion. It is sadly another example of inadequate science guiding medical advise.

  2. “Most primary care physicians don’t have the time or the knowledge to hold a detailed discussion of the pros and cons of PSA testing with individual patients at a routine office visit”

    How hard can it be to give a simple statement that no form of PSA screening has ever been shown to produce an improvement in overall survival? Too hard for most docs apparently.

    This is just more advocacy for yet more unproven yet harmful medical strategies from those with conflicts of interest. Absolutely appalling.

  3. Great Model for PSA Screening, but with Glaring Problem You Highlighted

    This approach will preserve scarce time at physical exams for more pressing matters and avoid confusing patients with information that is unlikely to be well absorbed because it is premature — i.e., presented before the patient actually needs to face the issue of possible prostate cancer. Drs. Vickers and Carlsson did a nice job of elucidating this problem in timing information in recent years (as in https://www.ncbi.nlm.nih.gov/pubmed/27459245 and interviews).

    You wrote above: “There is no mention of active surveillance as a potential first-line management strategy for patients found to have low-risk prostate cancer after a prostate biopsy.” That strikes me as the key deficiency in the proposed approach. There needs to be an informed presentation for patients with an elevated PSA that is a concern, prior to referral to a urologist in my view, with emphasis on other causes of elevation (especially infection and BPH), and highlighting the convincing research behind the effectiveness of active surveillance and its advantages. My impression is that many primary care physicians are not yet sufficiently well-informed to have that discussion, but the studies are there and clear, so this is a problem that can and should be remedied.

    Gerry: Men, prior to their PSA results that indicate a need for further work-up, are not ready for premature discussion of pros and cons of screening. Also, such recommended texts for such discussions have been based on woefully faulty and misleading information in the past that has likely often led men to under-estimate the value and over-estimate the harm of well-done screening. For instance, as recently as this year prominent physicians are quoting the grossly obsolete and misleading statistic that it takes 1,000 screenings to save one life from prostate cancer. We now have good evidence that screening is far more effective than that, especially when coupled with an active surveillance program if appropriate for the patient.

  4. David,

    You have a faulty understanding of the data. Check out the results from the ERSPC, which now has reported a substantial benefit of screening (as contrasted with a “significant” benefit in their highly premature initial report). Try comparing the numbers-needed-to-invite-to screen to save a life using the 9-year, 11-year, and 13-year follow-ups. See the trend? I find it appalling that so many doctors, including the US Preventive Services Task Force, have been unable to connect the dots and understand the benefit of wisely done screening.

  5. Dear Jim:

    I feel obliged to point out to you (yet again) that even the lead authors of the ERSPC study still do not believe that the 13-year data justify this type of population-based screening. Please see their statement on the first page of the ERSPC web site.

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