Many people don’t think twice about prostate cancer until it touches their lives. Maybe a friend gets diagnosed or a routine doctor visit raises some red flags. Suddenly, you may wonder what causes this type of cancer and whether you or a loved one could be at risk.

In this article, we’ll discuss what doctors know about the causes of prostate cancer and break down the most relevant risk factors. We’ll discuss who may be at the highest risk and how lifestyle and hormones come into play. Finally, we’ll briefly touch on what to expect when it comes to screening and diagnosis of prostate cancer.

What Are the Causes of Prostate Cancer?

Prostate cancer doesn’t have one single cause. It develops when cancer cells grow out of control because of genetic mutations (changes). These genetic changes happen inside the cell’s DNA. DNA acts like an instruction book that tells cells how to grow and divide properly.

When DNA is damaged, cells may grow out of control and become cancerous. When these cancer cells multiply, they can form tumors. In some cases, tumors can spread to other parts of the body.

Most DNA changes that are linked to prostate cancer happen slowly over time. However, about 10 percent of prostate cancer cases are related to inherited genetic changes (those passed down through families). Hormones and environmental factors can also affect how prostate cells grow.

11 Key Risk Factors for Prostate Cancer

Below, we’ll discuss 11 of the most common and well-studied prostate cancer risk factors. Having one or more of these risk factors doesn’t mean you’ll definitely get prostate cancer. It only means your chance of getting prostate cancer may be higher.

1. Age

The risk of developing prostate cancer rises steadily with age. The disease is rare before the age of 40, but becomes increasingly common as men reach the age of 50 and older.

Data from the National Cancer Institute Surveillance, Epidemiology, and End Results (SEER) program show how prostate cancer cases are distributed among males in different age groups in the United States:

• Ages 35 to 44 — About 0.3 percent
• Ages 45 to 54 — About 6 percent
• Ages 55 to 64 — About 29 percent
• Ages 65 to 74 — About 43 percent
• Ages 75 and older — About 22 percent

2. Family History of Prostate Cancer

Having a family history of prostate cancer can increase your risk of getting it, too. If a close family member, such as a father or brother, has been diagnosed with prostate cancer, your risk is about two to three times higher than that of the general population. Your risk may be even higher if that family member was younger when diagnosed or if more than one close relative has had the disease.

A family history of other cancers — such as breast, ovarian, or pancreatic cancer — may also raise your risk of developing prostate cancer.

3. Inherited Gene Mutations

Some people are born with inherited gene mutations that increase their risk for prostate cancer. The best-known genes linked to prostate cancer are BRCA1 and BRCA2. These genes are also connected to higher risks of breast cancer, ovarian cancer, and pancreatic cancer. For prostate cancer, BRCA2 is especially important because it is linked to a higher risk of developing the disease and a greater chance of having aggressive disease.

Lynch syndrome (also called hereditary non-polyposis colorectal cancer, or HNPCC) increases prostate cancer risk as well. Other genes that can increase risk include:

• ATM
• CHEK2
• HOXB13

These mutations are not common, but when they are present, they can greatly increase a person’s risk of prostate cancer.

4. Race and Ethnicity

African-American men and Caribbean men of African ancestry are at higher risk of developing prostate cancer than those other racial and ethnic groups, according to the American Cancer Society. They’re also more likely to be diagnosed at a younger age and with a more aggressive disease course.

Additionally, prostate cancer is less common in Asian American, Hispanic, and Latino men than in non-Hispanic white men, according to the American Cancer Society.

Health experts believe that genetics, environment, access to care, and social factors may all play a role in these differences.

5. Hormones and Testosterone Levels

Testosterone is an androgen, a type of sex hormone that supports normal prostate cell growth. Research shows that having normal testosterone levels doesn’t increase the risk of developing prostate cancer. However, if cancer cells are already present, testosterone can help fuel their growth.

Another hormone, called insulin-like growth factor 1 (IGF-1), helps regulate normal cell growth. Studies have found that people with higher IGF-1 levels may have an increased risk of developing prostate cancer.

6. Obesity

Obesity means having a body mass index (BMI) — a number calculated from height and weight — over 30. Researchers have found that people with obesity have a higher risk of being diagnosed with more aggressive prostate cancer or at a later stage.

This link may exist because obesity can cause changes in hormones and inflammation in the body, which can help cancer grow and make it harder to detect prostate cancer early.

7. Levels of Physical Activity

Regular physical activity may help lower the risk of developing prostate cancer and can also reduce the risk of dying from the disease. Exercise supports overall health, and its benefits go beyond weight loss. Physical activity may also make it easier to interpret prostate cancer screening tests, like the prostate-specific antigen (PSA) test and digital rectal exams. Having a higher body weight can make these tests harder to interpret, so staying active supports both prevention and early detection of prostate cancer.

8. Diet and Nutrition

Research shows that overall eating patterns may affect prostate cancer risk, though no single food causes or prevents the disease. Diets high in red meat, animal fat, and processed foods may slightly increase the risk. Eating fewer vegetables may also add to overall risk.

Some nutrients have been studied closely, but many findings are mixed or inconclusive. For example, some studies have found that eating a lot of calcium and dairy products may slightly raise prostate cancer risk.

9. Prostate Inflammation

Prostatitis (inflammation of the prostate) is most often caused by an infection. Some studies suggest that having a history of prostatitis may slightly increase a person’s risk for developing prostate cancer. However, the link isn’t fully clear.

Prostatitis can raise levels of prostate-specific antigen, a protein measured in blood tests used for prostate cancer screening. Higher PSA levels can lead to more testing, which can increase the likelihood of the cancer being detected.

10. Environmental and Lifestyle Factors

Some environmental and lifestyle factors may affect prostate cancer risk, though the links aren’t always clear. Research is ongoing, and many findings come from long-term studies that look at patterns over time.

Factors that may increase the risk include:

• Smoking, which is linked to more aggressive disease and worse outcomes
• Heavy alcohol use, especially when large amounts are consumed daily
• Exposure to certain chemical, such as pesticides or Agent Orange
• Sexually transmitted infections (STIs)

Other habits that may lower risk include:

• Maintaining a healthy weight
• Staying physically active
• Following a nutritious diet

11. Other Risk Factors

Researchers have also studied other potential risk factors, but so far, the evidence is mixed or limited. These factors may be linked to prostate cancer in some studies, but they haven’t been shown to directly cause prostate cancer. These include:

• Vasectomy
• Other environmental exposures, such as cadmium
• Radiation exposure from medical imaging

Prostate Cancer Screening and Diagnosis

Prostate cancer screening can help detect cancer early, before symptoms begin. The American Cancer Society recommends that men talk with their healthcare providers about the risks and benefits of screening.

According the American Cancer Society, these discussions and shared decisions should begin at:

• Age 50 for men at average risk
• Age 45 for men at high risk, including African American men and those with a close relative diagnosed before the age of 65
• Age 40 for men at even higher risk, such as those with more than one close relative diagnosed at an early age

Prostate cancer screening usually starts with PSA testing, which is done through a simple blood test. If the results raise concern, it doesn’t necessarily mean cancer. Your doctor may repeat the test, order imaging, or perform a digital rectal exam. They’ll explain the results to you and work with you to decide on the next steps.

Join the Conversation

On MyProstateCancerTeam, people share their experiences with prostate cancer, get advice, and find support from others who understand.

What risk factors are you most concerned about? Let others know in the comments below.