A prostate-specific antigen (PSA) test helps detect prostate cancer in men, but the test has some disadvantages. Recent research studies suggest that screening for prostate cancer with PSA tests may not lower actual deaths from prostate cancer. To help men weigh the benefits and risks of PSA screening, Cancer.Net talked with Derek Raghavan, MD, PhD.

Q: Why is there controversy surrounding PSA screening?

A: There is a lot of controversy on the issue of prostate cancer screening, including digital rectal exams (DRE) and PSA screening for several reasons:

1. Prostate cancer is a variable disease with two main types: one that grows very slowly and is less dangerous, and one that grows quickly, spreads to other organs, and may cause death. The more aggressive type (also called high-grade prostate cancer) needs treatment. What is difficult is that most men have the less aggressive type, and it can sometimes be quite difficult to tell the difference between the two types of cancer from a biopsy (removal of a small amount of tissue for examination under a microscope).
   
   
2. The tools used for prostate screening, DRE and PSA, are rather inaccurate, and that has led some doctors to question whether this is an appropriate way to screen for prostate cancer.
   
   
3. Until recently, there have been no well-designed clinical trials (research studies in people) that have actually proven that screening works in prostate cancer. For screening to be effective, it really needs to improve survival or increase the rate of cure, or at least cut down the side effects of treatment. Unfortunately, for prostate cancer, much of the controversy is focused on whether the cancer was just detected a bit earlier by screening, but without improving cure rates.
   
   
4. Two randomized clinical trials have now been reported. One clinical trial in the United States found no evidence that screening improves survival, and it actually seemed that the group of men who were screened suffered more complications. Another clinical trial in Europe showed that deaths from prostate cancer were reduced by screening, but total survival was the same. Also of importance, in men over the age of 75, survival was actually worse in the screened population. Putting the two studies together, there isn’t a very strong case at all for screening all men for prostate cancer. In my view, we should focus any screening activities on patients with a family history of prostate cancer, especially those with deaths from prostate cancer. Another important group is African American men, who have a higher death rate from prostate cancer. I want to emphasize that this is my clinical opinion on screening and not yet supported by hard data.

Q: What are the benefits and risks of PSA screening?

A: The theoretical benefits of screening for prostate cancer are (1) the potential to diagnose the cancer earlier at a time when it is curable; and (2) the potential to diagnose earlier so that less aggressive treatment is required. The risks of prostate screening are that it may identify the less aggressive type of prostate cancer that may not really need to be treated (especially in an older man), and that treatment may cause significant side effects, such as impotence (inability to get an erection) and incontinence (inability to control urine flow). The disappointment for physicians and patients is that the two recent clinical trials have not shown a very big difference in survival yet. Maybe they will in the future since the men will continue to be followed, but it is also possible that the lack of difference will remain. If later review shows that survival is improved by screening, then our position on this issue will change and we will advocate screening. Until then, it seems that the right approach is for the doctor and patient to allow sufficient time to discuss all the issues carefully when considering screening.

Q: What should older men know about PSA screening?

A: The same information discussed for men aged 40 to 70 applies largely to men who are older than age 70. However, they should be aware that the U.S. Preventive Health Task Force has recommended against screening men older than age 75 for prostate cancer, based on previous data. This situation is different from a setting where an older man is actually developing new urinary symptoms. Screening is a term that relates to the investigation of cancer in people without any symptoms.

Q: What questions should men ask their doctor about PSA screening and their risk of developing prostate cancer?

A: Men should ask whether any symptoms suggest that they might have a prostate disorder, whether they are at increased risk of having prostate cancer based on their history, and whether a prostate screening test could be helpful. They should also ask the doctor to discuss what is known about the accuracy of DRE and PSA testing, why there is controversy, and what the risks are by having a PSA test. Of importance, they should discuss with the doctor what would happen if the test(s) suggest the presence of prostate cancer, what would happen if it does not, and what the benefit or drawback is of doing nothing right now. If men have recent changes in urine stream, production of blood in urine or semen, or are experiencing the need to pass urine often during the day or night, they should talk with the doctor about checking out the set of symptoms.

Q: Where can men find more information on prostate cancer?

A: In addition to talking with the doctor, the Cancer.Net Guide to Prostate Cancer offers comprehensive information on prostate cancer, including information on symptoms, diagnosis, treatment options, and current research. Men can also read about a new guideline on drugs to help prevent prostate cancer. In addition, men who are completing treatment for prostate cancer can learn about possible side effects caused by treatment and ways to manage them with the help of the doctor.

Dr. Raghavan is Director of the Taussig Cancer Institute at Cleveland Clinic. He serves as Cancer.Net Associate Editor for genitourinary cancers and is Co-Chair of the ASCO Health Disparities Task Force.

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Last Updated: April 02, 2009