Prostate Cancer: Why You May Need Genetic Testing

It is currently estimated that 13% of men in the United States will develop prostate cancer within their lifetime, making it the most common cancer that occurs in men.

Because of this, the National Comprehensive Cancer Network (NCCN) suggests that all men over age 45 should discuss screening for prostate cancer with their health care providers. Screening typically consists of a simple blood test, called the Prostate-Specific Antigen (PSA) test, and can also include the Digital Rectal Exam (DRE), which is a manual exam of the prostate.

Early detection of prostate cancer is important, as it can result in more favorable outcomes.

The biggest risk factor for men to develop prostate cancer is age; as men get older, the risk to develop prostate cancer rises.

Studies have shown that race also plays a role in prostate cancer risk: African American men have a higher probability to develop prostate cancer than men of other ethnicities and are also more likely to have more aggressive prostate cancer or for the prostate cancer to occur at a younger age. The reasons for this are currently unknown.

Family history is another big risk factor toward developing prostate cancer; having a history of men in your family with prostate cancer can increase one’s own risk to develop it.  This is likely due to hereditary, or genetic, causes.

There are some cancer prevention genes, such as the commonly known BRCA1 and BRCA2 genes, that can elevate a man’s risk to develop prostate cancer if a mutation is present. These genes are frequently associated with breast and ovarian cancer in women, but certainly have an impact on men’s health, too.

As such, the NCCN guidelines were recently updated to recommend that all men with aggressive (metastatic or intraductal/cribriform histology) prostate cancer undergo genetic testing to determine if their cancer is hereditary.

In a recent study out of the University of Utah, genetic testing was obtained on all men who developed prostate cancer and were diagnosed at their hospital between June 2016 to December 20184. Of the 408 men that underwent genetic testing and had results available to review, 10.3% (42 men) were found to have a genetic mutation related to hereditary prostate cancer.

The majority of these mutations were in the BRCA2 gene (25.5%), but mutations were also found in the ATM gene and the CHEK2 gene. These latter two genes are associated with hereditary prostate cancer, breast cancer, pancreatic cancer (ATM), and colon cancer (CHEK2).

This finding validated the recent expansion of the NCCN guidelines to confirm genetic testing should be offered to all patients with aggressive prostate cancer.

Additionally, this study looked at various factors between patients with prostate cancer that may help predict if they would have a mutation in a hereditary prostate cancer gene. The authors did not find any factors that were more or less likely to help identify a mutation. This included looking at age, race, PSA scores, prostate cancer risk group (as defined by NCCN), or family history.

Thus, this adds even more justification as to why all men with aggressive prostate cancer should consider genetic testing, regardless of their family histories or other factors.

As targeted therapies become available to patients with hereditary cancer gene mutations, the option of genetic testing can change a man’s course of prostate cancer treatment.

Genetic testing results can also help provide an explanation for why a cancer occurred and can provide information to family members wanting to know their own risk of developing cancer.