Genetic Biomarker Test Calculates Recurrence, Survival Outcomes for Men With Prostate Cancer

A genetic biomarker test was found to accurately predict how men with high-risk prostate cancer will respond to radiation treatment and hormone therapy, according to a recent meta-analysis that was presented at the American Society for Radiation Oncology Annual Meeting.

The study, which included the examination of biopsy samples collected from 3 large-scale randomized clinical trials, indicated that physicians could use genetic test scores to individualize treatment for men with aggressive forms of prostate cancer.

“For a man with high-risk prostate cancer, this genetic score can be a very powerful prognostic tool that can tell us whether he is likely to be cured from treatment or is likely to see his cancer return again….I see this as a great opportunity to change the standard of care for patients in the future by using genomics to personalize therapy,” said Paul L Nguyen, MD, lead author of the study, a professor at Harvard Medical School, in a statement. Nguyen is also the vice chair of clinical research and director of genitourinary radiation oncology at the Dana-Farber Cancer Institute in Boston, Massachusetts.

Two-thirds of deaths attributed to prostate cancer occur in patients with high-risk prostate cancer, who often undergo radiation therapy and 2 years of hormone therapy as standard treatment. Balancing survival risk and quality of life is often a big concern for many patients; hormone therapy can cause uncomfortable adverse effects, including hot flashes and loss of libido, as well as possible cardiovascular and cognitive changes.

Researchers have shifted their focus to identifying prognostic biomarkers, which have the potential for use in developing more precise treatment guidelines and designating who might benefit from less therapy and which patients may benefit from additional treatment with newer hormonal agents.

The researchers used the Decipher biopsy test, which examines the activity of 22 genes in prostate tumors and produces a score that indicates the aggressiveness of a patient’s cancer.

"We are optimistic that this score can tell us which men should have their treatment de-intensified, meaning they will get less hormone therapy, and which men should have their therapy intensified, meaning they will get an additional, second-generation hormone therapy….With this genetic marker, we hope to personalize therapy for men with high-risk prostate cancer rather than having a one-size-fits-all approach," expressed Nguyen.

Decipher scores were calculated using RNA from 385 archival biopsy samples collected across 3 major prostate cancer trials. The genetic signature predicted which patients had a greater likelihood of developing distant metastases (HR, 1.24; 95% CI, 1.11-1.39), which had a higher risk of death due to their prostate cancer (HR, 1.27; 95% CI, 1.13-1.43), and which were more likely to die from any cause (HR, 1.12; 95% CI, 1.05-1.20). The rate of distant metastases at 10 years was 29% for patients whose scores indicated that they had a higher risk of metastases and 13% for those who had scores indicating a lower risk.

Although the Decipher test had been validated previously using tissue samples taken after patients underwent radical prostatectomy, the investigators’ current analysis examined tissue taken prior to the patients receiving treatment, when they had initially been diagnosed.

“This study is the first to validate a genetic biomarker for high-risk prostate cancer using pre-treatment archival tissue from large prospective randomized trials….Using archival tissue samples from a wide range of centers and patients—hundreds of cancer centers across the country—shows that this test can be helpful for many men with high-risk disease,” said Nguyen.

Additionally, the age of the samples meant that the investigators could examine long-term outcomes for patients with high-risk prostate tumors, potentially allowing patients to receive a complete follow-up for 20 to 30 years.

Nguyen emphasized that the Decipher test needs to be investigated further to confirm validity before it can become adapted widely.

Reference

Genetic biomarker test predicts recurrence and survival outcomes for men with high-risk prostate cancer. News release. American Society for Radiation Oncology. October 25, 2021. Accessed November 1, 2021. https://www.newswise.com/articles/genetic-biomarker-test-predicts-recurrence-and-survival-outcomes-for-men-with-high-risk-prostate-cancer