prostate

Prostate Cancer Screening: Is It Worth the Risk?

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If it’s a test done by modern medicine, then it must be good, right? More tests, more information, more procedures–certainly this must all lead to better health? Maybe not! Some tests can result in your being diagnosed with a “disease” that would never have caused you any harm, leading to potentially harmful treatments, increased anxiety, and increased health care costs, all for no discernible benefit.

For years, the prostate-specific antigen (PSA) blood test has been at the center of a test-vs.-no-test debate with the potential benefit of detecting and successfully treating early prostate cancers being weighed against the risk of false positives and unnecessary interventions. In October, the United States Preventive Task Force (USPTF), an independent panel of experts for prevention and primary care, proposed a new guideline advising that men should not be screened with the PSA test as “there is moderate or high certainty that the service has no net benefit or that the harms outweigh the benefits.” Although this is not yet an official recommendation, it adds fodder to an ongoing debate about whether or not PSA screening should be done. Here’s more background to help you understand the testing dilemma.

Prostate Cancer and PSA

Prostate cancer is the second most common cancer in men after skin cancer; one in six men in the US will eventually be found to have prostate cancer. In 2011, around 33,720 men died of prostate cancer, and more than 240,890 were diagnosed, according to estimates from the National Cancer Institute. Although these numbers are daunting, most men die with–not of–prostate cancer. In addition, even though men have roughly a 16 percent chance of being diagnosed with prostate cancer at some point, only about 3 percent die of the disease. From autopsy studies, we know that many men over 85 who die of other causes also have prostate cancer. Certainly, identifying harmful cancers and treating them if possible is a worthy goal, but it’s not clear that PSA testing results in better health; in fact, there’s evidence that it doesn’t.

Prostate-specific antigen, an enzyme made in the prostate, was discovered in 1970 and has been used as a general screening test for prostate cancer since the late 1980s. In theory, having a blood marker that could help detect and cure early cancers would be a great screening tool to have. The problem is that this is a flawed test. PSA levels are variable, and studies have shown there can be a significant amount of natural fluctuation that’s not related to prostate cancer. Elevations in PSA can also result from other prostate abnormalities, such as infections and inflammation, as well as use of certain over-the-counter drugs like ibuprofen. Even though an elevated PSA may not indicate cancer, abnormal tests prompt more investigation–with men being subjected to follow-up tests, potentially unnecessary antibiotics, and invasive biopsy procedures.

And here’s the kicker: Even when prostate cancers are detected by PSA screening, finding those cancers may not do patients any good. The USPTF panel based its proposed recommendation against prostate cancer screening on research showing that overall, the PSA test doesn’t save lives and that it can lead to unnecessary surgery and radiation treatment for slow-growing cancers that would never have caused harm. These interventions are not without serious side effects–a recent study in the Journal of the American Medical Association found that men’s chances of returning to a normal sex life after prostate cancer treatment can vary from 10 to 70 percent. There’s also no proof that PSA tests and earlier treatment offer any overall benefit for faster-growing, invasive cancers.

Dr. Richard Ablin, one of the researchers who originally discovered prostate-specific antigen, has been a leading spokesperson against using this marker for general prostate cancer screening. In a New York Times op-ed piece, he called the test “hardly more effective than a coin toss,” and continued, “As I’ve been trying to make clear for many years now, PSA testing can’t detect prostate cancer and, more important, it can’t distinguish between the two types of prostate cancer–the one that will kill you and the one that won’t.”

What Other Organizations Say

The 2011 USPTF drafted guidelines would be the most concrete in clearly recommending against using PSA tests for prostate cancer screening, but they’re in line with other organizations. While the American Urologic Association’s last best-practice recommendation from 2009 still supports testing, it also emphasizes the importance of men having a thoughtful conversation with their doctors about the risks and benefits of screening, including the risk for overdetection and overtreatment–that is, detecting cancers that would not cause harm and thus potentially subjecting men to unnecessary treatment. The 2010 American Cancer Society statement recommends that men who are at a higher risk for prostate cancer should “receive information–and have the opportunity to make an informed decision–about the uncertainties, risks, and potential benefits associated with prostate cancer screening.”

When the PSA Test Does Make Sense

For men who have been diagnosed with prostate cancer and have chosen to forgo any therapeutic intervention (doctors sometimes calls this a “watch-and-wait” approach), the PSA test can be a valuable tool to monitor progression of the disease. Similarly, for men who have already been treated for prostate cancer, be that with surgery, radiation, or with hormonal therapy, doctors usually order regular PSA tests to look for recurrence. A large increase in a patient’s PSA level, particularly a rapid rise in the number over a short period of time, is cause for concern and mandates additional testing–and possible intervention.

The Bottom Line on PSA Testing

The PSA is not a perfect test. There are limits to what a PSA level actually detects. Critics are concerned that potentially harmful interventions may result from pursuing a diagnosis and that even if a cancer is found, more harm than good may result. As a general screening tool, PSA has major flaws, not to mention costs (it’s been estimated that  $5.2 million would have to be spent on screening–and the interventions that follow it–to prevent a single death from prostate cancer).

That said, men, you should have an informed discussion with your doctor. If you have a personal or family history of prostate cancer or other risk factors, PSA testing may have a role in your health care. And whether you test or not, maintain a healthy lifestyle. Observational and clinical studies have linked the lifestyle factors outlined below with a reduced risk of developing aggressive prostate cancers and dying of the disease. Besides, more than just your prostate will benefit from this healthy approach!

  • Reduce or eliminate red meat and dairy from your diet.
  • Eat lots of vegetables. The lycopene in cooked tomatoes may be particularly helpful in guarding against prostate cancer.
  • Get aerobic exercise at least three times per week.
  • Find a practice that helps with stress reduction, such as yoga or meditation, and do it regularly.
  • Consider taking vitamin D3 and fish oil supplements (but talk with your health care provider before beginning any new supplement regimen).

Sources:

American Cancer Society. (2012). What are the key statistics about prostate cancer? Retrieved from http://www.cancer.org/Cancer/ProstateCancer/DetailedGuide/prostate-cancer-key-statistics

Brett, Allan S & Ablin, Richard J. (2011). Prostate-Cancer Screening–What the U.S. Preventive Services Task Force Left Out. N Engl J Med 2011; 365:1949-1951. doi:  10.1056/NEJMp1112191

National Cancer Institute. (2011). SEER Stat Fact Sheets: Prostate. Retrieved from: http://seer.cancer.gov/statfacts/html/prost.html

 

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