Pitfalls of Prostate Tests

Question: What can you tell me about the current methods for testing for prostate cancer?

Dr. Brownstein's Answer:

Typically, after age 50, men are advised to get a yearly rectal exam and PSA test, which assesses the level of prostate- specific antigen, an enzyme secreted by the gland. If the manual rectal exam is abnormal or the PSA level is elevated, the patient will be referred to a urologist for a further workup. Prostate cancer can only be diagnosed by a biopsy of the prostate gland. It is the reading of these tissue samples that confirms whether the patient has a malignancy.

Unfortunately, there are many pitfalls involved with prostate testing. First, the PSA level can be elevated for a number of reasons besides cancer, including prostatitis, an inflammatory condition that can cause painful and difficult urination. Second, I am not 100 percent in support of the procedure to biopsy the prostate gland. The biopsy procedure removes samples of prostate tissue. But most times this biopsy is done “blindly,” meaning the tissue is taken from random parts of the gland.

Even if certain areas of the prostate are suspected of being abnormal, the biopsy procedure is still unreliable as to whether or not the urologist will get a sample of the diseased tissue. Also, the biopsy itself has the potential to spread cancer. If the majority of prostate cancers are slow-growing — only 3 percent of affected men die from it — it’s possible that a biopsy will cause the abnormal cancerous cells to be released from the gland. And some men develop chronic inflammation of the prostate after a biopsy.

The biopsy of the prostate gland should be undertaken only after careful consideration. I am not opposed to all prostate biopsies. But I feel too many are being done in an (often) haphazard manner. I don’t think this is good medicine.

The most basic tenet of medicine is that you need an accurate diagnosis in order to formulate an effective treatment plan. This leads to the following question: If you don’t do the biopsy, how can you diagnose prostate cancer? The answer is: You can’t.

That is where the PSA test comes into play. If the PSA level is elevated, it may signal prostate cancer. So does everyone need an annual PSA test? No.

In the U.K., PSA testing is not used widely. Yet a comparison of prostate cancer incidence in the United States and the U.K. found the intensive PSA screening in the United States resulted in dramatic increases in prostate cancer incidence without a significant change in mortality between the two countries.

This would indicate that PSA screening in the United States is not giving us what we hoped it would: a decrease in the mortality rate from prostate cancer. What mass PSA screening does is create a population of men who now have to undergo painful diagnoses and treatments without evidence of these therapies changing the final outcome.

Furthermore, looking at the annual age-adjusted cancer death rates among males from 1930 to 2005 (the latest year available) shows the death rate for prostate cancer has not gone down; it has increased. That means that over the last 75 years our therapies — radiation, chemotherapy, hormonal blockade, and surgery — have been ineffective for most people.

I believe that doctors are overusing the PSA testing to diagnose a relatively common illness (prostate cancer) that has a fairly low (3 percent) mortality rate. If we had better therapies to treat the advanced disease, I would be in favor of universal PSA screening. Until that day comes, I am against it.

That is not to say the PSA test doesn’t provide useful information. It does. If the PSA level is elevated or rising at an unduly high rate, that could be a message to the patient to improve his diet, exercise, and detoxify.