November 15, 2011 in Features

Prostate predicament

Imperfect prostate cancer test leaves men with scary choice
Patricia Anstett Detroit Free Press
 

Roger Watkins’ test showed an elevated PSA reading, raising health fears, but further tests by his doctor showed that he did not have cancer.
(Full-size photo)

The PSA test

Q. What is PSA?

A. Prostate Specific Antigen (PSA) is a protein produced by the prostate gland. It can be measured in urine and blood.

Q. Does PSA find cancer?

A. It can, but it also detects elevations of the protein caused by benign prostate diseases, urinary tract and other infections, sexual activity and masturbation. That’s why men should not leap to conclude they have cancer, or undergo invasive tests if their PSA number is high.

Q. Should all men get the PSA test?

A. It’s a decision a man should make with his doctor. There’s disagreement about whether men should begin to have this discussion before age 50, though African Americans or those who have a family history of prostate cancer are likely to have the cancer diagnosed earlier.

Q. What’s a high PSA score?

A. Doctors used to set the number 4 as the point at which a man needed more tests. But that has changed as research found that PSA levels can rise with a man’s age, the size of his prostate and other factors. Generally, the higher the number, the more likely a man has a prostate problem, though not necessarily cancer.

Q. Are there tests currently available that better pinpoint cancer?

A. Yes, though there’s some debate about how much better they are. Some doctors say the size of the prostate gland itself needs to be measured when a man has a borderline PSA score.

There also are refinements of the standard PSA test. One tracks the changes in the PSA level over months. Another measures “free-PSA,” how much PSA winds up in the bloodstream. The lower the free-PSA number, the more likely a man is to have cancer.

More info

Find out more about the PSA test, as well provide comment on recent recommendations from the U.S. Preventive Services Task Force:

• National Cancer Institute: www.cancer.gov/cancertopics/factsheet/detection/PSA

• U.S. Preventive Services Task Force: www.uspreventiveservicestaskforce.gov

• American Urological Association: www.auanet.org

At 74, Roger Watkins had no desire for his doctor to poke around more to find out whether he had prostate cancer.

When a test came back in 2008 suggesting he might have it, Watkins and his urologist, Dr. Muzammil Ahmed, agreed to keep an eye on his prostate specific antigen (PSA) scores in the months ahead but to “leave well enough alone.”

Further examination showed that Watkins may have gotten an elevated score for other reasons, including his age and the size of his prostate. Tests this year showed that his score had dropped – from 4.2 to a safer 2.9.

“I don’t believe in rushing into anything,” says Watkins, a retired business process specialist who lives in Northville, Mich., with Marcia, his wife of 51 years.

Across the nation, men like Watkins are talking to their doctors about the latest controversy over PSA testing – particularly because new, more promising tests might be close to federal approval, perhaps just a year or two away.

The traditional PSA test, developed in 1991 by Dr. William Catalona, a Northwestern University urologist, has always been controversial because high scores often don’t mean prostate cancer.

A federal advisory committee last month said it could not recommend the test because it leads to unnecessary biopsies, surgery and other treatments that can cause death or permanent disabilities, such as incontinence.

The new tests promise to better identify men with prostate cancer, particularly an aggressive form of it.

A University of Michigan team, headed by Dr. Arul Cinnaiyan, is working with GenProbe, a San Diego molecular diagnostics testing firm, to develop a single test that finds two biomarkers of prostate cancer.

One of the biomarkers is a gene that fuses with others “that we believe is the one driving the disease,” Cinnaiyan says. The other biomarker is associated with more aggressive prostate cancer.

Cinnaiyan hopes the test will be more widely available next year through a national study. Doctors would be able to mail urine samples for analysis. The test would be a complement, not a replacement, for the PSA test and a digital rectal exam.

Another blood test, developed by Catalona, looks for a more specific antigen produced by prostate cancer cells.

This Pro-PSA score is factored into a formula to create a score of a man’s prostate health. The higher the number, the higher likelihood a man has cancer. That should let doctors know whether a biopsy is needed, Catalona says.

His test, now in development by the Beckman Coulter biomedical testing firm of Brea, Calif., awaits federal approval. It’s already available in Europe and Australia.

Until federal approval, men have to sort out their choices.

“PSA is far from perfect, but it still is the most accurate test we have today to detect any cancer,” says Ahmed, a urologist at the Oakwood Hospital & Medical Center in Dearborn, Mich.

“Prostate cancer is … the second leading cause of cancer death in men in the United States, after lung cancer. All discussions about PSA must be taken into that context.”

The most recent discussions were triggered by an Oct. 7 recommendation by the U.S. Preventive Services Task Force that healthy men shouldn’t routinely get PSA screening. The task force is part of the same advisory system that earlier this year said mammography does not benefit women under the age of 50.

“We tell our patients that screening should begin at 40 or 45 and after that, probably once a year is enough, unless the PSA changes by 0.5 in one year,” says Dr. Kenneth Kernen, director of urology at Beaumont Hospital, Royal Oak, Mich.

Men younger than 50 who have elevated PSA scores often are reluctant to wait to see whether those scores continue to rise, says Dr. David Wood, a University of Michigan urologist.

“Certainly men who are younger are more likely to proceed with a biopsy because they have a higher risk that the cancer will have a significant impact on their lives,” Wood says.

But because infections can trigger increases in the PSA score, doctors often prescribe antibiotics and retest a man’s PSA within a few months.

Dr. Isaac Powell, a Karmanos Cancer Institute urologist, believes the test is particularly important for U.S. black men, who are more than twice as likely to die from the cancer as white men.

“As a prostate cancer survivor, I take an aggressive approach” with black men and others with a family history of prostate cancer, he says.

One of Kernen’s patients, Robert Ford, 77, of West Bloomfield, Mich., saw no reason to wait. After seeing his PSA score rise to a 6, Ford insisted on a biopsy this year that found 12 aggressive tumors.

“My take is, any time anybody doesn’t have a PSA they are making a big mistake,” Ford says.

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