The presence of the TMPRSS2-ERG mutation in blood may predict how well patients with metastatic castration-resistant prostate cancer (CRPC) respond to docetaxel, according to study findings presented at the 2015 European Cancer Congress in Vienna.
Òscar Reig, MD, of Hospital Clinic, Barcelona, Spain, and colleagues prospectively evaluated TMPRSS2-ERG in peripheral blood mononuclear cells (PBMC) in 50 patients with metastatic CRPC treated with docetaxel. Patients with TMPRSS2-ERG had a significantly lower rate of PSA response to docetaxel compared with those who did not have TMPRSS2-ERG (12.5% vs. 68.3%). They also had a significantly lower median PSA progression-free survival (3.1 vs. 7.5 months), and lower median clinical/radiologic progression-free survival (3.1 vs. 8.2 months). In multivariate analysis, TMPRSS2-ERG was independently associated with a significant 3.7 times increased risk PSA progression and 6.3 times increased risk of clinical/radiologic progression.
“TMPRSS2-ERG predicts [a] low response rate to docetaxel and poor outcome in metastatic CRPC patients,” the authors concluded in a study abstract. “These data support its potential role as a biomarker to tailor treatment strategy.”