Prostate Testing To Prevent Cancer

Prostate cancer, a phrase once uttered in whispers, is now in the news almost daily. General Norman Schwarzkopf and more recently New York mayor Rudy Giuliani are only two of the famous men who have or have had the disease. They and thousands of others have had their cancers diagnosed with the help of a PSA test. PSA stands for "prostate specific antigen," a protein produced in the prostate gland and released into the blood. (The prostate, a small gland behind the bladder, produces seminal fluid.) PSA levels are normally very low, but rise when prostate disorders— such as infection, benign enlargement, or cancer—occur. Digital rectal exam (DRE), usually done at the same time as PSA testing, also helps detect some cancers, but not as many as the blood test.

The problem, though, is that nobody has ever been able to show that PSA testing actually saves lives. Do men live longer if they discover their cancers early and undergo treatment? There is still no definite proof, via a clinical trial, but the good news has been slowly accumulating. It now appears that the death rate from prostate cancer has declined since testing began.

For example, a study by National Cancer Institute researchers published in March found that for white men, the death rate from prostate cancer had declined below levels of 14 years ago, when PSA testing was first approved. (The death rate among African-Americans has also begun to decline, but not as much.) Among men aged 60 to 79, the death rate was even lower than that—lower than 50 years ago. Some researchers attribute this to PSA testing, but others disagree. Currently, some official organizations, such as the American Urological Association, recommend regular PSA testing for all men over 50. But other experts are less sure of the benefits and do not recommend routine PSA testing. This newsletter has recommended it in a limited way. What's behind these differences of opinion is a complicated story.

Prostate cancer is quite common. Autopsies have shown that 30% of men over 50 and 70% at age 80 have small prostate cancers that haven't spread or caused symptoms. But only 3% of men die from it. In many men the disease does not spread and has few symptoms, or none. On the other hand, it can be deadly—it kills more men (32,000 in the U.S. predicted this year) than any other cancer except lung cancer. And though this is typically an older man's disease, it sometimes strikes men in their fifties or even younger. For reasons not wholly understood, African-American men are more likely to have prostate cancer—and also more likely to die from it than other men.

The downside of PSA testing

A simple blood test that can help detect cancer might sound like a dream come true, but in fact the PSA test detects only high levels of PSA, not cancer. The only way to tell which men have cancer and which have some benign disorder is through a surgical biopsy—an expensive and unpleasant procedure. It's estimated that only about one-third of men with high PSAs turn out to have cancer. However, in one unpublished study presented recently at the meeting of the American Urological Association, researchers at the Washington University School of Medicine in St. Louis reported that of some 1,500 men undergoing surgical biopsies, only 165 turned out to have cancer. That's just over 10%, which is not very many, considering the expense, particularly the psychological expense for the men undergoing testing.

Another problem: There's no way to predict for sure which cancers (detected by biopsies) will be aggressive and which will stay confined to the prostate and cause few or no symptoms.

Still another: It's possible to have a low PSA and still have prostate cancer. Indeed, one in five men with prostate cancer do not have an elevated PSA. Moreover, as we've said, a high PSA can arise from other disorders, or be elevated for no apparent reason.

And another problem: Even if you're diagnosed with prostate cancer, there's no one best treatment. Surgery to remove the prostate and/or radiation are standard; but both treatments often produce such complications as impotence and urinary incontinence. For older men "watchful waiting" rather than treatment is sometimes best. This means frequent visits to the doctor for retesting and examination, with an eye to beginning therapy if the cancer progresses. Trials are underway to determine whether "watchful waiting" is better than immediate surgery.

The upside

In spite of all the drawbacks, millions of men are currently being tested, and death rates from prostate cancer appear to be declining markedly. In another recent report to the American Urological Society, researchers from Italy and Austria reported a big decline in prostate cancer deaths in the Austrian state of Tyrol, where PSA screening was offered free to men aged 45 to 75 beginning in 1993. Two-thirds of all males were screened, and the death rate plummeted—41% below expected levels in 1998. This study has received a lot of publicity but has not been published, and there could be many questions about this result. There are currently two large studies in progress, one in the U.S. and one in Europe. They are specifically designed to determine whether PSA screening decreases mortality. Results from this research will be available beginning in 2006.

We see no reason, therefore, to change our prior recommendations. Given the advantages and disadvantages of this test, a man should discuss the issues thoroughly with his physician before being tested. Here's our advice:

• If you are under 50 and have no symptoms of prostate cancer, and no family history of it, you need not be tested.

• If you are African-American or have a family history of prostate cancer, begin screening at age 50. Some doctors say you should begin at age 40.

• If you are 50 to 75 with no family history or other risk factors, you may choose not to be screened.

• If you are over 75, and symptom-free, you may choose not to be screened.

• If your PSA level turns out to be high, get retested before having a biopsy.

• If you are taking any drug (such as Proscar) or herbal product (saw palmetto) for prostate problems, be sure to tell your doctor before your test, since these products may affect PSA levels.

 

Reference Source 98,99,101