CANCER
June 6, 2012

New PSA Screening Guidelines

For most men the risks connected with PSA tests for prostate cancer outweigh the benefits.

The United States Preventive Services Task Force (USPSTF) released its final recommendations on PSA screening on May 22. The task force recommends against PSA screening for prostate cancer in all men, regardless of age. The rationale is that PSA screening does more overall harm than good.

The recommendations have already proven controversial, to say the least.

A Brief Overview: Why Prostate Cancer Issues Are So Controversial

Unlike most other cancers, prostate cancer is rarely fatal. Most prostate cancers grow very slowly and pose little short term health threat, but some grow quickly and are extremely dangerous. Because doctors rarely can tell the two types apart, they are simply unable to tell a patient who has been diagnosed with prostate cancer what the best treatment is. The ability of prostate-specific antigen, or PSA, screening to help detect small prostate cancers earlier means more men are faced with a decision for which there is no obvious right answer.

Studies suggest that nearly 90% of men with PSA-detected prostate cancer in the United States will undergo early treatment with surgery, radiation, or androgen deprivation therapy. Treatment of tumors that will never cause any symptoms has no upside, only a downside.

Many of these cancers might never have come to light or caused any harm had they not been detected by a PSA test. If doctors knew the best course of action to take after a prostate cancer diagnosis, PSA tests would be much less controversial. As it stands, there is a question whether the information they provide is medically useful.

The Rationale for the Recommendations: Why PSA Screening Should Stop

Autopsies reveal that about one-third of all men aged 40-60 had prostate cancer when they died. This rises to as high as 75% in men 85 or older. Yet very few of these men died of the cancer; in fact, most tumors were tiny ones that probably did not cause any symptoms in the patients. Treatment of the tumors could not have been of any benefit to these men. Yet other studies suggest that nearly 90% of men with PSA-detected prostate cancer in the United States will undergo early treatment with surgery, radiation, or androgen deprivation therapy. Treatment of tumors that will never cause any symptoms has no upside, only a downside.

The task force based its recommendation on two major PSA studies, one in the U.S. (PLCO) and the other conducted in seven European countries (ERSPC). The task force found no evidence from the U.S. study that PSA screening reduced the mortality rate from prostate cancer at all.

Roughly one-third of men who have prostate biopsy experience pain, fever, bleeding, infection, transient urinary difficulties, or other issues requiring clinician follow-up that the men consider a “moderate or major problem”; approximately 1% require hospitalization.

The European study found that screening prevents one death for about every 1,000 men aged 55-69 screened, with no benefit at all seen in five of the seven countries. But up to five men in 1000 who choose to treat their prostate cancer surgically die within one month of surgery and from 10-70 men opting for surgery will have serious complications stemming from it. Men who choose to treat their cancer with radiation therapy or surgery have a 20-30% rate of urinary incontinence or erectile dysfunction. And men who choose hormone therapy have a 40% risk of erectile dysfunction.

There is also the issue of false positives. PSA testing does give many false positives. The next step after a positive PSA test is usually a biopsy, where a small piece of prostate tissue is surgically removed for microscopic examination. This sounds like a simple procedure but it has many risks associated with it. The recommendations cite a study that suggests that roughly one-third of men who have prostate biopsy experience pain, fever, bleeding, infection, transient urinary difficulties, or other issues requiring clinician follow-up that the men consider a “moderate or major problem”; approximately 1% require hospitalization.

These are some of the reasons that the study concludes that PSA testing does more overall harm than good and recommends against such testing. Read the published recommendations to see the rest.

Another View: The Task Force Is Wrong--Here's What They Missed
Two editorials were published alongside the recommendations, one supporting them and the other opposing them. The opposing editorial criticizes the recommendations on several grounds. Its authors think that the task force has overestimated the harms and under-estimated the benefits of PSA testing. And they fear that if followed, the recommendations will take Americans back to an earlier age, when prostate cancer was often discovered at an advanced, incurable stage.

Among the criticisms of the study in the Annals of Internal Medicine editorial:

  • The PRCO and ERSPC studies were too short. Studies with a 10-year median follow-up should not be used to give blanket advice for 50- and 60-year old men, who are likely to live much longer than 10 more years
  • Both studies have methodological flaws which led to questionable mortality data. An alternative analysis of data from the Rotterdam portion of the ERSPC study showed that PSA screening reduced the risk of dying of prostate cancer by as much as 31%.
  • The recommendations are absolutely inappropriate for patients at higher than average risk of contracting prostate cancer, including men with a family history of prostate cancer and African-American men.
  • The authors of the recommendations focused too much on cancer mortality and did not sufficiently consider the pain and suffering that living with advanced cancer can cause.
  • Finally, the recommendations of the USPSTF carry great weight with Medicare and other health insurers. Despite the fact that the recommendations are merely advisory, if insurers use them as a reason to no longer pay for PSA testing, they may spell an end to the tests. Who will be willing (or able) to pay for a PSA test out of their own pocket?

The authors do not agree with a one-size-fits-all approach to PSA testing. In their own words: "At this point, we suggest that physicians review the evidence, follow the continuing dialogue closely, and individualize prostate cancer screening decisions on the basis of informed patient preferences."

Rules, Recommendations and Reality

Someone once said that when you put rules in place, people stop thinking. And while the task force issued recommendations, not rules, medical recommendations are often taken as ironclad rules, not the suggestions they started out as. One little-noted provision in the recommendations does recognize that doctors and other health care providers should individualize their treatment decisions for each individual patient or situation. And there are already some indications that doctors are continuing to do so.

More than half of those doctors surveyed in the new study believed that not ordering PSA tests put them at risk of being sued for malpractice.

In a recent Johns Hopkins survey of 125 primary care physicians, a large number of doctors said they faced significant barriers to stopping PSA testing in men who had been receiving it regularly. Reasons for this included patient expectations and the difficulty of explaining to patients why they should not be screened. And more than half of those surveyed in the new study believed that not ordering PSA tests put them at risk of being sued for malpractice.

And back in 2008, the task force issued a similar recommendation against PSA screening for men age 75 or over. A recent study indicates that the recommendation has so far been largely ignored; PSA screening rates for men 75 or older did not change between 2005 and 2010.

A Final Word for Patients

Are PSA tests useful or not? While the new recommendations don't offer the clear-cut guidelines that patients might like, they do offer a fuller picture of the issues involved, which will help men consider their options. Though it's not yet known what effect the recommendations may ultimately have, so far little has changed for patients. Patients who are interested in receiving a PSA test or who want to know more about the test should still discuss this with their doctor. And anyone who has been diagnosed with prostate cancer should do the same.

For more detailed information on the PSA test, see the National Cancer Institute's PSA test factsheet. And for more detailed information on the many issues of prostate cancer, see NCI's booklet, What you need to know about prostate cancer.

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