The Benefit of Combining Docetaxel with Androgen Deprivation Therapy in Localized and Metastatic Hormone-sensitive...

Area of Science:

• Oncology
• Molecular Biology
• Clinical Trials

Background:

• Docetaxel is a standard treatment for advanced prostate cancer (PC).
• Treatment benefits vary among patients, with a subset showing TMPRSS2-ERG gene fusion and ERG overexpression.
• Identifying biomarkers for docetaxel efficacy is crucial.

Purpose of the Study:

• To assess biomarkers, specifically ERG expression and Ki67, for predicting docetaxel efficacy in hormone-sensitive prostate cancer (HSPC).
• To evaluate the association of these biomarkers with patient outcomes in clinical trials.

Main Methods:

• Analysis of pretreatment prostate biopsies from two phase 3 clinical trials (GETUG 12 and GETUG 15).
• Immunohistochemistry staining for Ki67 and ERG.
• Univariate and multivariable analyses to examine biomarker associations with relapse-free survival (RFS) and progression-free survival (PFS).

Main Results:

• Ki67 was associated with worse RFS in GETUG 12 patients.
• Docetaxel-based chemotherapy improved failure-free survival in ERG-positive patients (pooled analysis).
• ERG-positive patients showed improved PFS with docetaxel in both localized and metastatic HSPC settings.

Conclusions:

• ERG expression is a predictive biomarker for docetaxel response in both high-risk localized and metastatic HSPC.
• Ki67 may serve as a prognostic factor in HSPC.