A blood test can predict the response of patients with advanced prostate cancer to treatments

July 25, 2018

An International Collaborative Study Between Lawson Health Research Institute, Sloan Memorial Kettering Cancer Center, Royal Marsden and Epic Sciences is one of the first to demonstrate that a blood test can predict How Advanced Prostate Patients The study used a liquid biopsy test developed by the molecular diagnostic company Epic Sciences that examines circulating tumor cells (CTCs) in blood samples from prostate cancer patients who decide whether to switch from hormone therapy to chemotherapy. CTCs are cancer cells that leave a tumor, enter the blood and invade other parts of the body, causing cancer to spread.

The test identifies whether the CTCs of a patient contain a protein called AR-V7 in the cell's nucleus. . The research team tried to determine if the presence of this protein predicted which treatment would best prolong a patient's life. They found that patients who tested positive for the protein responded better to taxane-based chemotherapy, while those who were protein-negative responded better to hormone-targeting therapy with drugs called receptor signaling inhibitors. androgens. These are the two classes of medications most commonly used to treat advanced prostate cancer.

"The study is focused on a critical decision point when patients and their oncologists choose the therapy to follow," says Dr. Alison Allan. Lawson and Chair, Department of Anatomy and Cell Biology at the Schulich School of Medicine and Dentistry at Western University. "We respond to a critical unmet need by validating that a blood test or liquid biopsy can be used to select a therapy that can prolong a patient's life."

Research Participants included 142 patients with advanced prostate cancer. Program at the London Health Sciences Center (LHSC) in London, Ontario; Memorial Sloan Kettering Cancer Center in New York; and the Royal Marsden in London, England. Patients had already undergone at least one series of hormone-unsuccessful treatments and were working with their oncologist to decide whether to switch to another hormone therapy or chemotherapy as a first-line treatment.

Therapies like ARS inhibitors work by slowing down or stopping the growth of cancers that use hormones to grow. The growth of prostate cancer is based on hormones called androgens, which include testosterone. Inhibitors of ARS block the production of male hormones to treat the recurrence or spread of prostate cancer

"ARS inhibitors are the first line of treatment preferred as they target the hormones that feed the prostate cancer cells. Says Dr. Allan. "However, at some point, cancer cells may find a way to survive without this fuel and become resistant to ARS inhibitors, in many cases through the production of the AR-V7 protein.

Although this study was aimed at predicting the best treatment for patients who had previously undergone at least one cycle of hormone-targeting therapy, a future goal of the team is to evaluate the use of this test or similar CTC blood tests to determine optimal treatment at past decision points in advanced prostate cancer care.The team also plans to collaborate more with Epic Sciences to evaluate different versions of the CTC blood test for d & # x14; 39, other types of cancer, such as lung cancer

Epic Sciences and Genomic Health partnership means the CTC blood test is now commercially available in the United States. Oncotype DX AR-V7 core detector.