A new diagnostic test could improve the prostate cancer experience for millions of men. Researchers at University College London (UCL) analyzed a tissue-based molecular test called Decipher to determine which men with high-risk prostate cancer were most likely to benefit from stronger treatment — and which might avoid unnecessary medication and side effects.

The analysis focused on abiraterone, a hormone therapy that was shown in the STAMPEDE clinical trial to cut the risk of death in half among men with high-risk, localized prostate cancer.

The findings were presented at the European Society for Medical Oncology (ESMO) Congress 2026 in Madrid, held Oct. 23–27.

Not every cancer is alike, and treating someone more aggressively than necessary could have "increased side effects and poorer quality of life," noted a UCL news release.

Because prostate cancers differ at the molecular level, not every patient benefits from adding hormone therapy.

To determine whether Decipher could help guide that decision, researchers examined test scores from more than 27,000 patients in real-world data and 401 men with non-metastatic prostate cancer who had participated in the STAMPEDE abiraterone trial.

Higher Decipher scores predicted worse outcomes, meaning the cancer is more likely to spread and additional treatment may be valuable. A low Decipher score suggested more intensive treatment may be unnecessary.

Lead researcher Dr. Sarah Howlett of UCL Cancer Institute commented in a statement that for men with very high-risk prostate cancer, preventing spread of the disease is "critical." "Understanding who benefits most from additional treatment can make a meaningful difference," she added. The findings suggest that genomic testing could help tailor treatment, according to the researcher.

Men with high-risk prostate cancer and low Decipher scores may face a lower risk of spread and could avoid more intensive therapy, while those with high scores may be the strongest candidates for additional treatment.

Identifying the same pattern in both a large, real-world dataset and a randomized clinical trial strengthens the findings, Howlett noted.

"But further validation in other datasets is needed before the test is used routinely to make these decisions," she said.

Elai Davicioni, medical director of urology for Decipher test maker Veracyte, also commented, "We believe this growing evidence gives physicians a stronger reason to use Decipher before making decisions that can affect both cancer outcomes and patients’ quality of life." Fox News senior medical analyst Dr. Marc Siegel, who was not involved in the study, also commented on the findings.

"Prostate cancer varies from person to person," he said. "Medical science is increasingly aware that it is not one size fits all." Localized prostate cancer, which has not yet spread, may contain mutations that predict how aggressive the disease will be and indicate whether it could respond to targeted therapies, Siegel noted.

Certain targeted therapies are being used more with widespread prostate cancer, according to the doctor, as they include "more powerful anti-androgens, which works not just on the testes, but on the adrenals as well." Hormone therapies have "significant side effects," including fatigue, and "don’t always help," he added.

Siegel said the study’s strength was its combination of a randomized treatment group with Decipher testing, which helped identify in advance which patients were most likely to respond to intensive hormone therapy. "This is the personalized, precise approach of the near future," he said.

Prostate cancer is the second-leading cause of cancer death behind lung cancer, according to the American Cancer Society.

About one in eight American men will be diagnosed with prostate cancer in their lifetime.