What is prevention?
Cancer prevention is action taken to lower the chance of getting cancer. By preventing cancer, the number of new cases of cancer in a group or population is lowered. Hopefully, this will lower the number of deaths caused by cancer.
To prevent new cancers from starting, scientists look at risk factors and protective factors. Anything that increases your chance of developing cancer is called a cancer risk factor; anything that decreases your chance of developing cancer is called a cancer protective factor.
Some risk factors for cancer can be avoided, but many cannot. For example, both smoking and inheriting certain genes are risk factors for some types of cancer, but only smoking can be avoided. Regular exercise and a healthy diet may be protective factors for some types of cancer. Avoiding risk factors and increasing protective factors may lower your risk but it does not mean that you will not get cancer.
Different ways to prevent cancer are being studied.
General Information About Prostate Cancer
Prostate cancer is a disease in which malignant (cancer) cells form in the tissues of the prostate.
The prostate is a gland in the male reproductive system. The prostate is just below the bladder (the organ that collects and empties urine) and in front of the rectum (the lower part of the intestine). It is about the size of a walnut and surrounds part of the urethra (the tube that empties urine from the bladder). The prostate gland produces fluid that makes up part of the semen. 
Anatomy of the male reproductive and urinary systems showing the ureters, bladder, prostate gland, urethra, penis, testicles, and other organs.
As men age, the prostate may get bigger. A bigger prostate may block the flow of urine from the bladder and cause problems with sexual function. This condition is called benign prostatic hyperplasia (BPH). BPH is not cancer, but surgery may be needed to correct it. The symptoms of BPH or of other problems in the prostate may be like symptoms of prostate cancer. 
Normal prostate and benign prostatic hyperplasia (BPH). A normal prostate does not block the flow of urine from the bladder. An enlarged prostate presses on the bladder and urethra and blocks the flow of urine.
Prostate cancer is the second most common cancer among men in the United States.
Prostate cancer is most common in older men. In the United States, about one out of every eight men will be diagnosed with prostate cancer. Most men diagnosed with prostate cancer do not die of it.
See the following PDQ summaries for more information about prostate cancer:
- Prostate Cancer Screening
- Prostate Cancer Treatment
Prostate Cancer Prevention
Avoiding risk factors and increasing protective factors may help prevent cancer.
Avoiding cancer risk factors may help prevent certain cancers. Risk factors include smoking, having overweight, and not getting enough exercise. Increasing protective factors such as quitting smoking and exercising may also help prevent some cancers. Talk to your doctor or other health care professional about how you might lower your risk of cancer.
The following risk factors may increase the risk of prostate cancer:
Age
Prostate cancer is rare in men younger than 50 years of age. The chance of developing prostate cancer increases as men get older.
Family history of prostate cancer
A man whose father, brother, or son has had prostate cancer has a higher-than-average risk of prostate cancer.
Race
Prostate cancer occurs more often in African American men than in White men. African American men with prostate cancer are more likely to die from the disease than White men with prostate cancer.
Hormones
The prostate needs male hormones to work the way it should. The main male sex hormone is testosterone. Testosterone helps the body develop and maintain male sex characteristics.
Testosterone is changed into dihydrotestosterone (DHT) by an enzyme in the body. DHT is important for normal prostate growth but can also cause the prostate to get bigger and may play a part in the development of prostate cancer.
Vitamin E
The Selenium and Vitamin E Cancer Prevention Trial (SELECT) found that vitamin E taken alone increased the risk of prostate cancer. The risk continued even after the men stopped taking vitamin E.
Folic acid
Folate is a kind of vitamin B that occurs naturally in some foods, such as green vegetables, beans, and orange juice. Folic acid is a man-made form of folate that is found in vitamin supplements and fortified foods, such as whole-grain breads and cereals. A 10-year study showed that the risk of prostate cancer was increased in men who took 1 milligram (mg) supplements of folic acid. However, the risk of prostate cancer was lower in men who had enough folate in their diets.
Dairy and calcium
A diet high in dairy foods and calcium may cause a small increase in the risk of prostate cancer.
The following protective factors may decrease the risk of prostate cancer:
Folate
Folate is a kind of vitamin B that occurs naturally in some foods, such as green vegetables, beans, and orange juice. Folic acid is a man-made form of folate that is found in vitamin supplements and fortified foods, such as whole-grain breads and cereals. A 10-year study showed that the risk of prostate cancer was lower in men who had enough folate in their diets. However, the risk of prostate cancer was increased in men who took 1 milligram (mg) supplements of folic acid.
Finasteride and dutasteride
Finasteride and dutasteride are drugs used to lower the amount of male sex hormones made by the body. These drugs block the enzyme that changes testosterone into dihydrotestosterone (DHT). Higher than normal levels of DHT may play a part in developing prostate cancer. Taking finasteride or dutasteride has been shown to lower the risk for prostate cancer, but it is not known if these drugs lower the risk of death from prostate cancer.
The Prostate Cancer Prevention Trial (PCPT) studied whether the drug finasteride can prevent prostate cancer in healthy men 55 years of age and older. This prevention study showed there were fewer prostate cancers in the group of men that took finasteride compared with the group of men that did not. The number of deaths from prostate cancer was the same in both groups. Men who took finasteride reported more side effects compared with the group of men that did not, including erectile dysfunction, loss of desire for sex, and enlarged breasts. In the PCPT, the men who took finasteride who did have prostate cancer had more aggressive tumors, but a follow-up analysis of the PCPT found that these men did not have more aggressive tumors.
The Reduction by Dutasteride of Prostate Cancer Events Trial (REDUCE) studied whether the drug dutasteride can prevent prostate cancer in men aged 50 to 75 years at higher risk for the disease. This prevention study showed there were fewer prostate cancers in the group of men who took dutasteride compared with the group of men that did not. The number of less aggressive prostate cancers was lower, but the number of more aggressive prostate cancers was not. Men who took dutasteride reported more side effects than men who did not, including erectile dysfunction, loss of desire for sex, less semen, and enlarged breasts.
The following have been proven not to affect the risk of prostate cancer, or their effects on prostate cancer risk are not known:
Selenium and vitamin E
The Selenium and Vitamin E Cancer Prevention Trial (SELECT) studied whether taking vitamin E and selenium (a mineral) will prevent prostate cancer. The selenium and vitamin E were taken separately or together by healthy men 55 years of age and older (50 years of age and older for African American men). The study showed that taking selenium alone or selenium and vitamin E together did not decrease the risk of prostate cancer.
Diet
It is not known if decreasing fat or increasing fruits and vegetables in the diet helps decrease the risk of prostate cancer or death from prostate cancer. In the PCPT trial, certain fatty acids increased the risk of high-grade prostate cancer while others decreased the risk of high-grade prostate cancer.
Multivitamins
Regular use of multivitamins has not been proven to increase the risk of early or localized prostate cancer. However, a large study showed an increased risk of advanced prostate cancer among men who took multivitamins more than seven times a week.
Lycopene
Some studies have shown that a diet high in lycopene may be linked to a decreased risk of prostate cancer, but other studies have not. It has not been proven that taking lycopene supplements decreases the risk of prostate cancer.
Cancer prevention clinical trials are used to study ways to prevent cancer.
Cancer prevention clinical trials are used to study ways to lower the risk of developing certain types of cancer. Some cancer prevention trials are conducted with healthy people who have not had cancer but who have an increased risk for cancer. Other prevention trials are conducted with people who have had cancer and are trying to prevent another cancer of the same type or to lower their chance of developing a new type of cancer. Other trials are done with healthy volunteers who are not known to have any risk factors for cancer.
The purpose of some cancer prevention clinical trials is to find out whether actions people take can prevent cancer. These may include eating fruits and vegetables, exercising, quitting smoking, or taking certain medicines, vitamins, minerals, or food supplements.
New ways to prevent prostate cancer are being studied in clinical trials.
Information about clinical trials supported by NCI can be found on NCI's clinical trials search webpage. Clinical trials supported by other organizations can be found on the ClinicalTrials.gov website.
About This PDQ Summary
About PDQ
Physician Data Query (PDQ) is the National Cancer Institute's (NCI's) comprehensive cancer information database. The PDQ database contains summaries of the latest published information on cancer prevention, detection, genetics, treatment, supportive care, and complementary and alternative medicine. Most summaries come in two versions. The health professional versions have detailed information written in technical language. The patient versions are written in easy-to-understand, nontechnical language. Both versions have cancer information that is accurate and up to date and most versions are also available in Spanish.
PDQ is a service of the NCI. The NCI is part of the National Institutes of Health (NIH). NIH is the federal government's center of biomedical research. The PDQ summaries are based on an independent review of the medical literature. They are not policy statements of the NCI or the NIH.
Purpose of This Summary
This PDQ cancer information summary has current information about prostate cancer prevention. It is meant to inform and help patients, families, and caregivers. It does not give formal guidelines or recommendations for making decisions about health care.
Reviewers and Updates
Editorial Boards write the PDQ cancer information summaries and keep them up to date. These Boards are made up of experts in cancer treatment and other specialties related to cancer. The summaries are reviewed regularly and changes are made when there is new information. The date on each summary ("Updated") is the date of the most recent change.
The information in this patient summary was taken from the health professional version, which is reviewed regularly and updated as needed, by the PDQ Screening and Prevention Editorial Board.
Clinical Trial Information
A clinical trial is a study to answer a scientific question, such as whether one treatment is better than another. Trials are based on past studies and what has been learned in the laboratory. Each trial answers certain scientific questions in order to find new and better ways to help cancer patients. During treatment clinical trials, information is collected about the effects of a new treatment and how well it works. If a clinical trial shows that a new treatment is better than one currently being used, the new treatment may become "standard." Patients may want to think about taking part in a clinical trial. Some clinical trials are open only to patients who have not started treatment.
Clinical trials can be found online at NCI's website. For more information, call the Cancer Information Service (CIS), NCI's contact center, at 1-800-4-CANCER (1-800-422-6237).
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The best way to cite this PDQ summary is:
PDQ® Screening and Prevention Editorial Board. PDQ Prostate Cancer Prevention. Bethesda, MD: National Cancer Institute. Updated <MM/DD/YYYY>. Available at: https://www.cancer.gov/types/prostate/patient/prostate-prevention-pdq. Accessed <MM/DD/YYYY>. [PMID: 26389260]
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Last Revised: 2023-10-20
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