New research indicates that the Decipher Prostate Genomic Classifier offers an important tool for guiding treatment decisions in patients with metastatic prostate cancer, particularly in predicting who may benefit from chemotherapy with docetaxel.

Findings from the multicenter, prospective, phase 3 STAMPEDE trial, published in Cell, demonstrate that the Decipher test can predict which patients will benefit from treatment intensification with docetaxel. The test, a 22-gene panel developed through RNA whole-transcriptome analysis, was applied to prostate cancer samples collected during the trial.

For patients with metastatic disease, the addition of docetaxel to standard androgen deprivation therapy significantly improved survival in those with a high Decipher score, while no such benefit was observed in patients with lower scores. This distinction underscores the test’s ability to identify those most likely to respond positively to docetaxel, a finding consistent across both low- and high-volume metastatic subgroups. Professor Gerhardt Attard, MD, PhD, director of the UCL Cancer Institute and a co-investigator of the STAMPEDE trial, emphasized that while docetaxel improves survival, clinicians have lacked reliable tools to identify the patients most likely to benefit. The Decipher test’s predictive ability therefore has significant clinical value.

Further analysis revealed a meaningful biomarker–docetaxel interaction through whole-transcriptome analysis of tumor samples. Patients with PTEN-inactive tumors demonstrated a more favorable response to docetaxel, and when combined with a high Decipher score, this translated into a 45% reduction in the risk of death with the addition of docetaxel. This subgroup represented 28% of the metastatic tumors studied, highlighting the potential for refined patient selection based on genomic and molecular features.

Although the main focus was on docetaxel, investigators also examined whether Decipher could predict benefit from abiraterone. Patients with higher Decipher scores appeared to derive greater benefit, but the interaction was neither statistically significant nor clinically decisive, as both high- and low-score groups experienced meaningful improvements with abiraterone.

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