About one in nine men will be diagnosed with prostate cancer during their lifetime. Recently, innovation in treatment approaches for advanced prostate cancer has provided hope to patients fighting this hard-to-treat disease. Researchers have found that defects in certain genes, called mutations, can play a role in prostate cancer that has spread to other parts of the body, also known as metastatic prostate cancer. Identifying these mutations can help inform doctors of targeted treatments for that type of disease.

Dr. Neal Shore, M.D., F.A.C.S., medical director and CPI at Carolina Urologic Research Center, founding director at CUSP Clinical Research Consortium, and director of National Urology Research at 21^st Century Oncology discusses the importance of testing for certain mutations in advanced prostate cancer and the potential impact the identification of these mutations can have on treatment decisions.

What is metastatic castration-resistant prostate cancer?

Metastatic castration-resistant prostate cancer (mCRPC) occurs when cancer has spread to other parts of the body, and no longer responds to a medical or surgical treatment that lowers testosterone. Approximately 10%-20% of those with advanced prostate cancer will develop castration-resistant prostate cancer (CRPC) within approximately 5 years of their original diagnosis. At least 84% of these men will have metastases (spread of the cancer beyond the prostate) at the time of CRPC diagnosis.

Prostate cancer is the second-most common cancer in men. Five-year survival for mCRPC is low, at about 31%, and extending survival remains a key goal for treating these men.

What role do genetics play?

Researchers have recently found defects, or mutations, in certain genes that play a role in metastatic prostate cancer. In some cases, people can be born with healthy genes that can change or become altered over the course of their life, and these genetic markers, also called biomarkers, are then acquired. In other cases, people can be born with altered genetic markers, also known as germline mutations, which have been inherited through familial genes. Some of these mutations are associated with an increased risk of prostate and other cancers, including breast, ovarian, and pancreatic.

What is biomarker testing?

There are two types of biomarker testing that look for genetic mutations in our cells: (1) genetic testing for inherited mutations, also known as mutations that can be passed down through family genetics and (2) biomarker testing for acquired mutations, also known as mutations that form later in life. Cancer patients may have either of these mutations and knowing this information can help physicians create a more personalized treatment plan and may inform cancer risk for other family members if the mutation is found to have been inherited. Biomarker testing is important for men who have been diagnosed with prostate cancer, especially those with metastatic prostate cancer, to learn more about the genetic makeup of their tumor. Testing is done on a small sample of bodily fluid or tissue—usually blood or saliva. Testing can also be done on a small sample of the tumor itself.

Why should men with metastatic prostate cancer get biomarker testing?

Certain medical society guidelines recommend biomarker testing and genetic testing for all men with metastatic prostate cancer to determine whether they have an inherited or acquired genetic mutation that is relevant to their cancer. If such a mutation is identified, this can help patients get more tailored, individualized treatment based on the genetic makeup of their tumor. Men with certain mutations may respond to certain types of treatments, like chemotherapy or targeted therapies.

When should biomarker testing be done?

While biomarker testing can be completed at any stage of a patient’s cancer journey, it is recommended that this testing is completed at diagnosis. This approach may help oncologists develop comprehensive treatment plans, which may impact patients’ treatment trajectory and even prognosis. People with cancer who are interested in biomarker testing should talk to their doctor.

Unfortunately, since the start of COVID-19 there has been a large drop in cancer screenings and diagnoses, with the prostate cancer diagnosis rate dropping by 49.1% in April 2020 when compared to the previous year. This steep rate of decline in diagnosis may lead to a future increase of patients with later-stage cancer, which can be harder to treat. People who may have a higher risk of cancer or are experiencing new or troubling symptoms should talk to their doctor.

For resources on COVID-19 and cancer care, patients, caregivers, and healthcare professionals can visit http://www.covid19cancerresources.com.

*Dr. Shore was not compensated for his participation in this article. ©2020 AstraZeneca. All rights reserved.