Use of imaging tests in low-risk prostate cancer — striking the right balance

An article published a couple of weeks ago in the Journal of the National Cancer Institute looks at the effects of a physician education campaign in Sweden to reduce the inappropriate use of bone scans and other imaging tests among men with an initial diagnosis of low-risk prostate cancer.

It is widely understood that imaging tests are over-utilized in the initial evaluation of men diagnosed with low-risk forms of prostate cancer (clinical stage ≤ T2a; Gleason score ≤ 6; and a PSA level < 10 ng/ml). Very, very few such men will gain any benefit from the use of bone scans or CT scans (let alone PET scans) because they are at no or extremely low risk for even micrometastatic let alone evident metastatic disease. Such tests are discouraged in low-risk patients in all known clinical guidelines. And yet all too many physicians continue to give these tests to patients who really don’t need them.

Starting in the year 2000, the National Prostate Cancer Register (NPCR) of Sweden initiated a major effort to decrease national rates of inappropriate prostate cancer imaging by disseminating utilization data along with the latest imaging guidelines to urologists in Sweden. The new paper by Makarov et al. (freely available as a full text article) offers detailed information on the outcomes of this educational effort, which may be of considerable relevance to the situation in the USA. (See also this commentary on the Science 2.0 blog site.)

A few months ago, the American Society of Clinical Oncologists (ASCO) and the American Urological Association (AUA) concurred in stating that imaging studies were widely over-utilized in the USA in the evaluation of risk for men diagnosed with early stage, low-risk prostate cancer. The following was the first of the top five recommendations made to urologists by the AUA as part of the “Choosing Wisely” initiative designed to discourage physicians from over-use of inappropriate medical procedures:

  • “A routine bone scan is unnecessary in men with low-risk prostate cancer.

Similarly, medical oncologists were advised by ASCO that the following was the second of their top five recommendations:

  • “Don’t perform PET, CT, and radionuclide bone scans in the staging of early prostate cancer at low risk for metastasis.”

There is almost complete consensus about this issue among specialists in the management of low-risk prostate cancer. (Although there may well be exceptional cases when other facts might suggest that scans are appropriate, routine use of such tests among men with a diagnosis of low-risk disease is simply not justifiable or even beneficial.)

It is in this context that we may be able to learn from the Swedish experience (which almost exactly replicates findings from a much smaller, pilot study carried out in the USA some years ago).

Here is what Makarov et al. report, based on data from a retrospective analysis of data from effectively all men diagnosed with prostate cancer in Sweden between 1998 and 2009:

  • The database included 99,879 patients.
  • 36 percent of these patients (i.e., just under 36,000) were given imaging studies within 6 months of prostate cancer diagnosis.
  • Overall use of such imaging studies decreased significantly over time.
    • Among low-risk patients, the imaging rate decreased from 45 percent to 3 percent (P < 0.001).
    • Among high-risk patients, the imaging rate decreased from 63 percent to 47 percent (P < 0.001).
  • All Swedish regions experienced clinically and statistically significant (P < 0.001) decreases in prostate cancer imaging.
  • There was, however, significant variation in the decrease in use of imaging tests from region to region across Sweden.

The authors are careful to note that while the Swedish education effort was highly successful in reducing the inappropriate use of imaging tests among men with low-risk disease over a 10-year period, it also lead to a small and undesirable reduction in the use of highly appropriate imaging tests among high-risk patients most likely to benefit from the application of such tests!

Quoted on the commentary on the Science 2.0 blog site, Dr. Makarov states that:

The caveat here is that when guidelines are implemented to limit the inappropriate use of a healthcare resource, the appropriate use of that resource should be simultaneously encouraged — otherwise those patients who most need the resource may no longer have access to it. But the true lesson from this study is that inappropriate utilization of healthcare resources can be reduced by giving feedback to practitioners.

The reasons for the over-use of imaging tests in the early work-up of men with low-risk prostate cancer here in the USA may well include “defensive medicine” and the fear of legal action; they may also (at least sometimes) include a financial interest in centers that carry out such scans. The “New” Prostate Cancer InfoLink would encourage any newly diagnosed patient with low-risk disease to question the need for imaging tests like bone scans or CT scans that he was told he “needed” to have. We would actually go further and state that it may well be perfectly reasonable for health insurance providers to require pre-approval (“pre-clearance”) for such imaging tests in men with low-risk disease and better guidance about what might be indications that justified such tests in men initially diagnosed with low-risk prostate cancer. Such testing is costing us billions of dollars a year and there is no known justification for such testing in the vast majority of men with low-risk disease.

Finally, for those readers who may think that there must be some form of prejudice at work here, and that no one would consider restricting such imaging tests in women, here is the recommendation from ASCO on the role of imaging tests in women with low-risk breast cancer:


  • “Don’t perform PET, CT, and radionuclide bone scans in the staging of early breast cancer at low risk for metastasis.”

It is precisely the same recommendation.

2 Responses


    There are a number of factors pushing health care costs per person downward, factors that are often overshadowed by factors pushing costs upward. Reducing these unnecessary tests for low-risk patients looks like an important way of reducing costs per prostate cancer patient overall. Moreover, it appears that much of the potential is unrealized as many doctors are still prescribing these tests despite a number of years of guidance that they are not of value to low-risk patients.

    I’m wondering what percentage of the average workup cost per newly diagnosed prostate cancer patient is associated with these unnecessary bone and CT scans. I reviewed several of the backup documents but did not see information about that. Does anyone know?

    As prostate cancer is such a prevalent disease, eliminating such scans when they are valueless may be important in making the economics of the Affordable Care Act work.

  2. Dear Jim:

    The costs of such imaging tests depend on where they are being done and who is paying for them (like everything else in health care). As usual, the lack of cost transparency in health care is killing us all.

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