Genomic Test Could Help Doctors Decide Which High-Risk Prostate Cancer Patients Need Abiraterone

At a major cancer conference in Madrid, Dr. Sarah Howlett of the UCL Cancer Institute stood up to present a new analysis from the STAMPEDE clinical trial. The question she was addressing is one doctors have wrestled with for years: among men with high-risk prostate cancer, who actually needs the more intensive treatment, and who would do just as well without it?

The stakes are not small. Prostate cancer is the most common cancer in men, and in 2013 it affected more than 1 million men worldwide. It does not behave the same way in every patient. Treating someone more aggressively than necessary is associated with more side effects and a poorer quality of life. Abiraterone, the drug at the center of the study, lists fatigue among its side effects.

STAMPEDE had already shown that adding abiraterone, a hormone therapy, to standard treatment for men with high-risk, localized prostate cancer could halve the risk of death from the disease and slow its overall progression. But not every trial of extra hormonal therapies in high-risk prostate cancer has shown a benefit. So the UCL team asked whether a further test, the Decipher tissue-based molecular test, could pick out the men who stand to gain the most.

They drew on two datasets. One was real-world data covering 27,607 men, of whom 5,956 were analyzed for outcomes. The other was 401 men with non-metastatic prostate cancer who had been randomized within the STAMPEDE abiraterone trial.

Higher Decipher scores consistently predicted worse outcomes. For every 0.1 increase in the score, the adjusted hazard ratio for distant metastasis was 1.49, and the hazard ratio for dying of prostate cancer was 1.38. The score also predicted which patients whose cancer had not yet reached the lymph nodes would benefit from adding abiraterone to prevent spread to distant parts of the body.

Howlett said that for men with very high-risk disease, preventing spread is critical, and knowing who benefits most from extra treatment can make a meaningful difference. In her reading, men with high-risk disease but a low Decipher score have low rates of spread and could potentially be spared more intensive treatment, while those with a high score could be prioritized for it. She noted that seeing the same pattern in both a large real-world dataset and a randomized trial strengthens the findings, but said further validation in other datasets is needed before the test is used routinely for these decisions.

The UK context adds weight. In January, NHS England announced it would roll out abiraterone for men in England with high-risk locally advanced prostate cancer within weeks. Patients with similar risk profiles in Wales and Scotland already had access on the NHS. In the UK, the standard treatment for prostate cancer is androgen deprivation therapy.

Elai Davicioni, medical director for urology at Veracyte, the U.S. diagnostics firm that makes Decipher, said the growing evidence gives physicians a stronger reason to use the test before making decisions that affect both cancer outcomes and quality of life. He said the findings extend Decipher's predictive evidence to another consequential choice: whether adding abiraterone will meaningfully help a man with very high-risk disease.

For now, the finding is a promising signal rather than a change in practice. The next step is confirmation in other datasets.