Decipher Genomic Classifier Identifies Patients Who Benefit from Triplet Therapy in Metastatic Hormone-Sensitive Prostate Cancer

A major advancement in metastatic hormone-sensitive prostate cancerhas emerged from the ENZAMET trial: analysis using the Decipher genomic classifier shows that men with very high-risk tumor profiles benefit significantly from adding docetaxel to standard hormone therapy. Patients with a Decipher score above 0.85 who received the triplet regimen (ADT plus enzalutamide plus docetaxel) had improved overall survival compared to ADT plus enzalutamide alone, with an estimated hazard ratio of 0.75 after statistical adjustment for treatment selection bias. This represents the first validation of Decipher for predicting docetaxel benefit against a modern ADT-ARPI backbone, extending earlier findings from CHAARTED and STAMPEDE that tested it on ADT alone.

The Decipher genomic classifier is a 22-gene RNA assay performed on primary tumor tissue. While the exact gene weightings remain proprietary, extensive validation has shown that higher scores reliably identify men at greater risk of metastatic progression in localized settings and now also predict poorer prognosis in metastatic hormone-sensitive disease. The historical validation in CHAARTED and STAMPEDE confirmed that high Decipher scores predict which men benefit from adding docetaxel to ADT. ENZAMET extends this into the contemporary era of combined ADT and androgen receptor pathway inhibitor therapy.

The clinical application addresses a persistent conundrum: when should triplet therapy versus doublet therapy be used in metastatic hormone-sensitive prostate cancer? Since ENZAMET left docetaxel use at physician discretion, there was no pure randomized comparison of ADT-ARPI with or without docetaxel. The Decipher cutpoint of 0.85 now offers objective data to guide this decision beyond clinical characteristics alone. For patients fit for chemotherapy whose clinical features create uncertainty about triplet benefit, the test provides a more informed decision process. A score above 0.85 strengthens the argument for triplet therapy, while a lower score supports doublet therapy alone and helps avoid unnecessary toxicity.

The analysis required propensity score adjustment because patients receiving docetaxel had significantly higher rates of poor-prognosis, high-volume disease and a higher rate of scores above 0.85. While the sophisticated adjustment cannot fully eliminate residual confounding from physician selection bias, it moved closer to what would occur in a randomized trial. The results represent Level 1B evidence from a prospective-retrospective biomarker analysis with a pre-specified statistical plan and cutpoint defined before examining any ENZAMET data.

This finding shifts genomic classifiers from purely prognostic tools to treatment-selection instruments in the triplet era. This approach respects the biological heterogeneity of prostate cancer and provides concrete resolution for when intensified therapy adds meaningful survival benefit versus when hormonal therapy alone suffices.

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