Can Prostate Cancer Be Prevented?

There is no sure way to prevent prostate cancer. Many risk factors such as age, race, and family history can’t be controlled. But there are some things you can do that might lower your risk of prostate cancer.

Body weight, physical activity, and diet
The effects of body weight, physical activity, and diet on prostate cancer risk are not clear, but there are things you can do that might lower your risk.

Some studies have found that men who are overweight may have a slightly lower risk of prostate cancer overall, but a higher risk of prostate cancers that are likely to be fatal.

Studies have found that men who are physically active on a regular basis have a slightly lower risk of prostate cancer. Vigorous activity may have a greater effect, especially on the risk of advanced prostate cancer.

Several studies have suggested that diets high in certain vegetables (including tomatoes, cruciferous vegetables, soy, beans, and other legumes) or fish may be linked with a lower risk of prostate cancer, especially more advanced cancers. Examples of cruciferous vegetables include cabbage, broccoli, and cauliflower.

Although not all studies agree, several have found a higher risk of prostate cancer in men whose diets are high in calcium. There may also be an increased risk from consuming dairy foods.

For now, the best advice about diet and activity to possibly reduce the risk of prostate cancer is to:

• Eat at least 2½ cups of a wide variety of vegetables and fruits each day.
• Be physically active.
• Stay at a healthy weight.

It may also be sensible to limit calcium supplements and to not get too much calcium in the diet. (This does not mean that men who are being treated for prostate cancer should not take calcium supplements if their doctor recommends them.)

Vitamin, mineral, and other supplements
Vitamin E and selenium: Some early studies suggested that taking vitamin E or selenium supplements might lower prostate cancer risk.

But in a large study known as the Selenium and Vitamin E Cancer Prevention Trial (SELECT), neither vitamin E nor selenium supplements were found to lower prostate cancer risk. In fact, men in the study taking the vitamin E supplements were later found to have a slightly higher risk of prostate cancer.

Soy and isoflavones: Some early research has suggested possible benefits from soy proteins (called isoflavones) in lowering prostate cancer risk. Several studies are now looking more closely at the possible effects of these proteins.

Taking any supplements can have both risks and benefits. Before starting vitamins or other supplements, talk with your doctor.

Medicines
Some drugs might help reduce the risk of prostate cancer.

5-alpha reductase inhibitors
5-alpha reductase is an enzyme in the body that changes testosterone into dihydrotestosterone (DHT), the main hormone that causes the prostate to grow. Drugs called 5-alpha reductase inhibitors, such as finasteride (Proscar) and dutasteride (Avodart), block this enzyme from making DHT. These drugs are used to treat benign prostatic hyperplasia (BPH), a non-cancerous growth of the prostate.

Large studies of both of these drugs have been done to see if they might also be useful in lowering prostate cancer risk. In these studies, men taking either drug were less likely to develop prostate cancer after several years than men getting an inactive placebo.

When the results were looked at more closely, the men who took these drugs had fewer low-grade prostate cancers, but they had about the same (or a slightly higher) risk of higher-grade prostate cancers, which are more likely to grow and spread. Long term, it’s not clear if these drugs affect death rates, as men in these studies had similar survival whether or not they took one of these drugs.

These drugs can cause sexual side effects such as lowered sexual desire and erectile dysfunction (impotence), as well as the growth of breast tissue in some men. But they can help with urinary problems from BPH such as trouble urinating and leaking urine (incontinence).

These drugs aren’t approved by the FDA specifically to help prevent prostate cancer, although doctors can prescribe them “off label” for this use. Right now, it isn’t clear that taking one of these drugs just to lower prostate cancer risk is very helpful. Still, men who want to know more about these drugs should discuss them with their doctors.

Aspirin
Some research suggests that men who take a daily aspirin might have a lower risk of getting and dying from prostate cancer. But more research is needed to show if the possible benefits outweigh the risks. Long-term aspirin use can have side effects, including an increased risk of bleeding in the digestive tract. While aspirin can also have other health benefits, at this time most doctors don’t recommend taking it just to try to lower prostate cancer risk.

Other drugs
Other drugs and dietary supplements that might help lower prostate cancer risk are now being studied. But so far, no drug or supplement has been found to be helpful in studies large enough for experts to recommend them.