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More doubts about prostate cancer screening

On Father’s Day last month, Sen. John Kerry, D-Mass., and radio shock jock Don Imus co-authored an op-ed for the Boston Globe in which they argued that men needed to be sure they received regular preventive screening check-ups for prostate cancer. Both men are prostate cancer survivors.

“Screening for prostate cancer is the only option,” they wrote.

But therein lies a big, big problem — and yet another medical controversy. Just a few days after that op-ed ran, a review article in the medical journal CA: A Cancer Journal for Clinicians reported that the PSA blood test, routinely used to screen for prostate cancer, saves few lives, wastes money and often leads to risky and unnecessary treatments.

An editorial that accompanied the review noted that not a single well-designed clinical trial has yet to show that PSA screening reduces the death risk from prostate cancer.

“PSA screening has remained a controversial topic,” wrote the editorial’s authors, with considerable understatement.

What the test is

The PSA test, which measures the blood levels in men of a protein called prostate-specific antigen, was originally developed to monitor the progress of patients after treatment for prostate cancer. This disease claims the lives of more than 27,000 men in the United States each year, making it the second leading cause of cancer deaths (after lung cancer) in American men. PSA levels increase when cancer is present, but they also increase with certain benign prostate conditions — and with age. In addition, most prostate cancers grow very slowly and remain confined to the prostate gland, never causing any health problems. Thus, as the authors of both journal articles pointed out, PSA screening has led to the overdiagnosing and overtreatment of prostate cancer. This is no small matter, for the treatments for prostate cancer can have serious adverse effects, including impotence and incontinence.

Today, more than 55 percent of American men aged 50 or older undergo this screening test annually.

Blind faith
On the topic of benefits versus risks, the editorial was unambiguous:

The real impact and tragedy of prostate cancer screening is the doubling of the lifetime risk of a diagnosis of prostate cancer with little if any decrease in the risk of dying from this disease. In 1985, before PSA screening was available, an American man had an 8.7% lifetime risk of being diagnosed with prostate cancer and a 2.5% lifetime risk of dying from the disease. Twenty years later, in 2005, an American man had a 17% lifetime risk of being diagnosed with prostate cancer and a 3% risk of dying from prostate cancer.

The editorial concluded that the collective data from studies “cannot justify mass screening and indeed appear to justify support for a recommendation against mass screening.”

Wrote the authors:

For nearly 2 decades, testing has been based on blind faith in early detection as opposed to being based on evidence of a decrease in mortality as observed in well-designed clinical trials. Prostate cancer screening and the treatment of early stage disease is also a profitable industry. Despite discouraging findings from now 4 randomized trials of prostate cancer screening, much of the controversy surrounding the use of PSA as a population screening test remains unresolved. The high prevalence of PSA testing will be difficult to reverse. If we are to stem the spiraling costs of health care, we must move toward the use of evidence-based rather than the faith-based or profit-based practice of medicine.

What should men do about the PSA test? The editorial recommends talking about the issue with your physician and then making a “shared decision.” I suggest that before you go in for that talk, you read both the review and the editorial in CA: A Cancer Journal for Clinicians. The full-text versions are available free at the links I provided above.

Comments (5)

  1. Submitted by Kim Garretson on 07/07/2009 - 06:10 pm.

    I’m sorry, but this debate makes me angry because, and this is my own biased opinion, the reporters on this debate do not have the cold, hard facts. They only have what the journals are reporting on trial outcomes. But, I’ve yet to see data from the actuarial specifics inside the health insurers about the real costs of the PSA blood test (cheap) combined with the costs of biopsies (expensive) in light of the percentages of false positives from the PSA test. Also, the costs of implants, drugs, surgeries and other treatments for diagnosed cancers. If all of these costs were revealed from within the healthcare industry, and combined with the number of diagnosis and deaths, my gut tells me the real story here is not that the PSA test is ineffective and reducing the number of simple, cheap blood tests is a way to cut healthcare costs. I think the real story is the insurance industry’s math tells them they can absorb 27K deaths a year and remain profitable.

    I agree with the last statement about a “shared decision”, and reading the material suggested can’t hurt either, but again, I doubt the full & real story is to be found anywhere.

    And finally, while men should read about the ‘aggregate’ as suggested, they should also talk to fellows like me. I’m not a member of the aggregate. The PSA test saved my life.

  2. Submitted by Lee Smith on 07/09/2009 - 02:49 pm.

    I also respectfully request that you as a reporter read the many critiques of these poorly controlled and incomplete studies. Does the fact that approx half of the men in the non screened control actually had PSA testing make you raise your eyebrows. More more importantly the diagnosis, treatment and follow up regimes in current practice are far advanced from anything in the so called “studies”. Check out up to date urologists (e.g. http://www.drcatalona.com) to learn the other side. Funny how Otis Brawley is always out there opposing PSA screening, isn’t it! How come you aren’t citing other authorities advancing the opposite view and minimally stating both sides since your opinion is no more valid then mine. I take that back — mine is more valid since I have been there — diagnosed with fairly agressive prostate cancer, as a result of biopsy following follow up PSA testing. Now it’s true that I don’t really know what would have happened without the screening nor do any of the studies provide insight. Would I have discovered the cancer before it metasticized? would years of treatment for invasive cancer kept me alive? is that the life I would chose — no — Im glad it was found and glad it was removed. Screening of women for breast canceer is also unfortunately under siege since many of the discoved cancers are not (yet) invasive and women who get Mastectomies to avoid invasive breast cancer are being accused of over treatment. Screening plus education give us the opportunity to learn of our status and the possible outcomes and thus make an informed decision. Avoiding screen provides no information and allows us to live in blissful ignorance unless and until God forbid our cancer spreads. Predictive tools now exist to combine PSA results with biopsy results and estimate the odds of invasive cancer. Then one can decide whether or not they want to risk the odds. I hope that any health policy will continue to give us that right and ability as individuals to be treated as such. A lack of a positive result does not prove the negative, but rather in this case is probably a product of poorly designed experiments as pointed out by many authorities in prostate cancer. So if you want to wait a few years until it’s “proven” that screening indeed helps in discovering some cancers that will become invasive, as logic and common sense dictate, I hope the results come in before it’s too late and you are not just a statistic used to help prove the obvious — that screening is better than ignorance.

  3. Submitted by Lee Smith on 07/09/2009 - 08:22 pm.

    As expected — psa attacked first, mammography next:

    http://news.yahoo.com/s/ap/20090709/ap_on_he_me/eu_med_breast_cancer_overtreatment,

    Look at how similar the arguments opposing mammography/psa screening are:

    .
    Re mammography:

    “Some cancers never cause symptoms or death, and can grow too slowly to ever affect patients. As it is impossible to distinguish between those and deadly cancers, any identified cancer is treated. But the treatments can have harmful side-effects and be psychologically scarring.”…
    Doctors and patients have long debated the merits of prostate cancer screening out of similar concerns that it overdiagnoses patients. A study in the Netherlands found that as many as two out of every five men whose prostate cancer was caught through a screening test had tumors too slow-growing to ever be a threat.”

    The flaw in all these arguments is of course that although early detection includes those who will not ever suffer from cancer, it also includes many — a majority — who will. So the need is not to eliminate screening but rather to find more effective ways of monitoring identified patients and predicting which group a given person is in — one who will get agressive invasive cancer and one who will not. Until that happens it seems that it is common sense to get screened and then attempt as best you can to determine whether you are in the “harmless cancer” group of the (majority) who will get spreading cancer. Then give it your best shot — try to get rid of it or hope it will go away — but YOU make the call — not a government, not a doctor, not an insurance company!!!

  4. Submitted by Ross Williams on 07/10/2009 - 05:45 pm.

    If you aren’t going to act on the results of screening there is no point in spending money to be screened.

    The claim has always been that early detection leads to early treatment and early treatment improves chances of survival. The numbers don’t seem to support that. It appears that screening has doubled the number of people diagnosed with prostate cancer while only marginally increasing the number whose death is attributed to prostate cancer.

    Because of side effects, early treatment may well reduce the quality of life while doing nothing to lengthen it.

  5. Submitted by Lee Smith on 07/12/2009 - 11:36 pm.

    Mr. Willians:

    Get tested but don’t run off to “cure your cancer” because of a single PSA reading. Rather, I would recommend (even before you take any PSA readings) you find a good urologist who can explain the nuances of the risks you face as a man, what you can learn about your health and your future from PSA screening, and what decisions you will have to make if troublesome PSA readings show up. Here is an abstract of the latest:

    Prostate Specific Antigen Best Practice Statement: 2009 Update American Urological Association

    Abstract
    Prostate cancer is the most common noncutaneous cancer in men in the United States. Despite its prevalence, the natural history of this disease is remarkably heterogeneous. In many patients, the cancer progresses slowly, resulting in tumors that remain localized to the prostate gland. Although potentially life-threatening, such cancers are most often curable. Many patients with low grade and volume cancers may be candidates for active surveillance. In other patients,
    however, tumor growth may be more rapid, resulting in cancer spreading beyond the confines of the prostate. In such cases, long-term survival may be considerably diminished compared to survival associated with organ-confined cancers. Strategies for managing prostate cancer have therefore been aimed at early detection, with selective, tailored treatment.

    Prostate-specific antigen (PSA) is a tumor marker currently used for early detection of prostate cancer. Measurement of serum PSA levels has significant clinical application in other areas of prostate disease management. The purpose of this report is to provide current information on the use of PSA testing for: (1) the evaluation of men at risk for prostate cancer, (2) the risks and benefits of early detection (3) assistance in pretreatment staging or risk assessment, ..

    The report is an update of the previous AUA PSA Best Practice Policy 2000.
    There are 2 notable differences in the current policy. First, the age for obtaining a baseline PSA has been lowered to 40 years. Secondly, the current policy no longer recommends a single, threshold value of PSA which should prompt prostate biopsy. Rather, the decision to proceed to prostate biopsy should be based primarily on PSA and DRE results, but should take into account multiple factors including free and total PSA, patient age, PSA velocity, PSA density, family history, ethnicity, prior biopsy history and comorbidities.

    In addition, although recently published trials show different results with regard to the impact of prostate cancer screening on mortality, both suggest that prostate cancer screening leads to overdetection and overtreatment of some patients. Therefore, the AUA strongly supports that men be informed of the risks and benefits of prostate cancer screening before biopsy and the option of active surveillance in lieu of immediate treatment for certain men newly diagnosed with prostate cancer.

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