Health - Causes of Prostate Cancer

What Causes Prostate Cancer?

The exact causes of prostate cancer are not known. Several risk factors for developing prostate cancer have been identified, but which of these risk factors cause a prostate cell to become cancerous is not fully known. 


For a cancer to develop, changes must occur in the chemicals that make up the DNA, which makes up the genes in the cell. The genes control how the cell works, for example, how quickly the cell grows, divides into new cells, and dies, as well as correcting any mistakes that occur in the DNA of the cell to keep the cell working normally. 

Cancer occurs when certain genes that either control the growth or death of the cell are affected, which results in abnormal cell growth and/or death. Genes are inherited (passed on from parents to their children) and thus some changes in the genes (gene mutations) that increase the risk of developing cancer may be inherited. 

For prostate cancer, approximately 5%-10% of prostate cancers are due to inherited gene changes. Several inherited genes have been identified that increase the risk of prostate cancer, including RNASEL, BRCA 1, and BRCA 2, DNA mismatch genes, HPC1, and HoxB13. Kote-Jarai and colleagues identified that men who carry a hereditary mutation in homeobox 13 (HoxB13) have a higher than average risk of developing prostate cancer. 

In a systematic review and meta-analysis the investigators noted that in these men with the HoxB13 mutation, the risk of prostate cancer is also affected by a family history of prostate cancer and the year of their birth. Gene changes may also be acquired (develop during the course of your life). These changes are not passed on to children. Such changes may occur when a cell normally undergoes growth and division. It is thought that at times during normal cell growth, risk factors may affect the DNA of the cell.

What Are The Risk Factors For Prostate Cancer?

Certain risk factors may predispose a person to prostate cancer. These include the following:

• Age: Sixty percent of cases of prostate cancer arise in men over 65 years of age. The disease is rare in men under 40.

• Race or ethnicity: African-American men and Jamaican men of African ancestry are diagnosed with prostate cancer more often than are men of other races and ethnicities. Asian and Hispanic men are less likely to develop prostate cancer than are non-Hispanic white males.

• Family history: Prostate cancer can run in families. A man whose father or brother (first-degree relative) has or had prostate cancer is twice as likely to develop the disease. The younger the family member is when he is diagnosed with prostate cancer, the higher the risk is for male relatives to develop prostate cancer. The risk of developing prostate cancer also increases with the number of relatives affected.

• Nationality: Prostate cancer is more common in North America, Europe (especially northwestern countries in Europe), the Caribbean, and Australia. It is less common in Asia, Africa, and South and Central America. Multiple factors, such as diet and lifestyle, may account for this.

• Genetic factors: Mutations in a portion of the DNA called the BRCA2 gene can increase a man's risk of getting prostate cancer, as well as other cancers. This same mutation in female family members may increase their risk of developing breast or ovarian cancer. However, very few cases of prostate cancer can be directly attributed to presently identifiable genetic changes. Other inherited genes associated with an increased risk of prostate cancer include RNASEL, BRCA 1, DNA mismatch genes, HPC1, and HoxB13.

• Other factors: High-fat diets (fatty foods) and diets high in red meats and fatty foods and low in fruits and vegetables appear to be associated with a higher risk of developing prostate cancer. Obesity is also linked to a higher risk of the disease. Increased calcium intake and dairy foods may increase the risk of prostate cancer.

• Smoking, a history of sexually transmitted diseases, a history of prostatitis (inflammation of the prostate), and a history of vasectomy have not been proven to play a role in causing prostate cancer. The role of fish oil in risk of prostate cancer remains under investigation.