What Causes Prostate Cancer?

The prostate is a small gland that helps with the production of semen in people assigned male at birth. It is located below the bladder and in front of the rectum. Prostate cancer develops when healthy cells in the prostate mutate (change) and begin to grow and divide uncontrollably, forming a mass called a tumor.

The exact cause of prostate cancer is not yet fully understood. A combination of risk factors—including age, family history, geographical location, and race—are known to increase the risk of prostate cancer. Researchers are exploring possible links between prostate cancer development and exposure to certain chemicals, body weight, and diet.

This article covers what we know about what causes prostate cancer, including risk factors that can increase the likelihood of developing the disease. 

Known Risk Factors

Cancer occurs when gene mutations in cellular DNA cause cells to grow and divide in an uncontrolled way. Eventually, these abnormal cells lump together to form tumors that can invade nearby tissue. Sometimes these cells break away from the original tumor and spread (metastasize) to other areas of the body.

Prostate cancer begins in the prostate—a walnut-sized gland that is part of the reproductive system in people assigned male at birth. Researchers don’t know exactly what causes prostate cancer, but certain risk factors are associated with an increased risk of the disease. 

Age 

The risk of developing prostate cancer increases with age. It is rarely diagnosed in people under the age of 40. After the age of 50, the chance of having prostate cancer rises, and about 60% of all prostate cancers are diagnosed after the age of 65.

Geographical Location 

Certain parts of the world have a higher incidence of prostate cancer. It is most common in North and Western Europe, Australia, North America, the Caribbean islands, and South Africa. Multiple factors likely play a role in the increased rates of prostate cancer in some countries, including differences in access to screening tests, diet, and other lifestyle factors.

Family History

People with a family history of prostate cancer have an increased risk of developing the disease. Your risk of developing the disease is about 2 to 3 times higher if you have a first-degree relative (e.g., parent, sibling, child) who had prostate cancer.

Possible Risk Factors

Researchers are exploring the possible connection between certain factors that may play a role in the development of prostate cancer.

Diet 

Several studies have investigated the possible link between dietary habits and prostate cancer risk. Some research suggests that eating a diet high in saturated fats, red meats, processed foods, and dairy may increase the risk of aggressive prostate cancer. Though the research is unclear, eating a plant-based diet rich in fruits and vegetables may help lower the risk of the disease.

Body Weight 

Studies investigating the connection between body weight and the risk of prostate cancer have been inconclusive. While obesity does not seem to be a direct cause of prostate cancer, some research suggests that people with obesity may be at an increased risk of developing more aggressive forms of the disease. Obesity is associated with an increased risk of dying from prostate cancer.

Chemical Exposures

Exposure to certain types of chemicals may increase the risk of prostate cancer. Firefighters, for example, are regularly exposed to carcinogens (substances known to cause cancer), such as combustion chemicals created by fires. The protective equipment firefighters wear also contains suspected carcinogens. Farmers exposed to pesticides and fertilizers also have a greater risk of developing prostate cancer.

Prostatitis 

Prostatitis is inflammation of the prostate gland. The condition can be acute (temporary) or chronic (ongoing). Studies show a link between chronic prostatitis and an increased risk of prostate cancer. Researchers theorize that chronic inflammation associated with prostatitis may play a role in the development of cancer.

Is Prostate Cancer Hereditary?

About 10% of all prostate cancer cases are related to inherited gene mutations. Prostate cancer that runs in families is known as familial prostate cancer. Gene mutations linked to familial prostate cancer include:

• BRCA1 and BRCA2: The same genes known to increase the risk of breast and ovarian cancers are linked to a greater risk of prostate cancer. This means if people in your family have a history of prostate, breast, or ovarian cancers, you may have a higher chance of developing prostate cancer. 
• Lynch syndrome: Also known as hereditary nonpolyposis colorectal cancer (HNPCC), Lynch syndrome is an inherited condition associated with an increased risk of many types of cancer (particularly colon and rectum), including prostate cancer. 
• RNASEL: Normally, this gene helps abnormal cells die. Inherited mutations in the RNASEL gene may inhibit the tumor-suppressing function of the gene. Research suggests this may contribute to the risk of developing prostate cancer, especially in Black and Hispanic people assigned male at birth.
• HOXB13: Mutations in this gene are associated with an increased risk of aggressive prostate cancers. People assigned male at birth with these mutations are also more likely to develop the disease at a young age.

If you have family members with a history of prostate cancer, breast cancer, colorectal cancer, and/or ovarian cancer and want to understand your own hereditary risk, talk to your healthcare provider about genetic testing. 

Who Gets Prostate Cancer?

About 1 in 8 people assigned male at birth will be diagnosed with prostate cancer in their lifetime. Some people are more likely to develop prostate cancer than others. Factors that increase your likelihood of developing prostate cancer include:

• Age: The risk of prostate cancer rises steadily after age 50. About 60% of all prostate cancer cases are diagnosed in people aged 65 and older. 
• Ethnicity and sex: Black people assigned male at birth are more likely to develop prostate cancer and are more likely to be diagnosed with more aggressive forms of the disease at a younger age. They also have a higher risk of mortality compared to people of other races. The reason for this is unclear, but societal and social barriers may play a role. Asian American and Hispanic people assigned male at birth have a lower risk of prostate cancer than non-Hispanic white people.
• Family history: People with a family member who had prostate cancer have a 2 to 3 times higher-than-average risk of developing prostate cancer.

A Quick Review

Prostate cancer develops when abnormal cells in the prostate grow uncontrollably and form a tumor. The exact cause of prostate cancer is unknown, but certain risk factors are known to increase the risk of the disease, including age, race, family history, and geographical location. Other risk factors, such as body weight, diet, exposure to certain chemicals, and prostatitis may also play a role.