A breakthrough study by researchers at Lawson Health Research Institute in London, Ontario, Memorial Sloan Kettering Cancer Center and the Royal Marsden Epic Sciences in England is the first to demonstrate that a simple blood test can predict how advanced prostate cancer patients will respond to specific treatments. This test will help patients choose the most beneficial path of treatment and hopefully, prolong their lives based on their specific DNA.

The study, published in Scienmag, explains that the new technology involves a liquid biopsy test that examines the circulating tumor cells (CTC’s) in blood samples from patients with advanced prostate cancer who are deciding which form of treatment works best for their particular case.

The tests identifies a protein called AR-V7 which is found in the nucleus of CTCs. Researchers found that the patients who tested positive for this protein responded best to a certain form of chemotherapy while those who tested negative for this protein responded better to hormone-targeting therapy with drugs called androgen-receptor (ARS) inhibitors. These are the two most widely used drug classes to treat advanced prostate cancer.

“The study focused on the critical decision point when patients and their families and their oncologists are choosing that therapy to use next,” says Dr. Alison Allan, a scientist at Lawson. “We are addressing a critical and yet unmet need by validating that a blood test can be used to help select the most appropriate therapy that may prolong a patient’s life.

Other than skin cancer, prostate cancer is the most common cancer in American men with 164,690 new cases each year and 29,430 deaths annually.

The CTC blood test is now commercially available in the United States as the Oncotype DX AR-V7 Nucleus Detect.