“Researchers have created a test that they say can predict whether a man is at high risk of prostate cancer recurrence.
“The research team, led by Prof. Robert Bristow of the Princess Margaret Cancer Centre and the University of Toronto, both in Canada, presented their findings at the 33rd conference of the European Society for Radiotherapy and Oncology (ESTRO33) in Vienna, Italy.
“For men with cancer confined to the prostate, surgery and precision radiotherapy are the primary treatments. However, Prof. Bristow explains that during initial treatment, whether the cancer has spread outside the prostate often goes undetected. This means the cancer will return in 30-50% of patients.”
Dal Pra A, Lalonde E, Sykes J, Warde F, et al. Clinical Cancer Research. Aug 5, 2013.
“BACKGROUND: Pre-clinical data suggest that TMPRSS2-ERG gene fusions, present in about 50% of prostate cancers (PCa), may be a surrogate for DNA repair status and therefore a biomarker for DNA damaging agents. To test this hypothesis, we examined whether TMPRSS2-ERG status was associated with biochemical failure after clinical induction of DNA damage following image-guided radiotherapy (IGRT). METHODS: Pre-treatment biopsies from two cohorts of intermediate-risk PCa patients (T1/T2, GS < 8, PSA < 20ng/mL) (> 7 years follow-up) were analyzed: (1) 126 patients with DNA samples assayed by array Comparative Genomic Hybridization for TMPRSS2-ERG fusion (CGH-cohort); and (2), 118 patients whose biopsies were scored within a tissue microarray (TMA) immunostained for ERG overexpression (surrogate for TMPRSS2-ERG fusion) (IHC-cohort). Patients were treated with IGRT with a median dose of 76 Gy. The potential role of TMPRSS2-ERG status as a prognostic factor for biochemical relapse-free rate (bRFR; nadir + 2 ng/mL) was evaluated in the context of clinical prognostic factors in multivariate analyses using Cox proportional hazards models. RESULTS: TMPRSS2-ERG fusion by aCGH was identified in 27 patients (21%) in the CGH-cohort and ERG overexpression was found in 59 patients (50%) in the IHC-cohort. In both cohorts TMPRSS2-ERG status was not associated with bRFR on univariate or multivariate analyses. CONCLUSIONS: In two similarly-treated IGRT cohorts, TMPRSS2-ERG status was not prognostic for bRFR, in disagreement with the hypothesis that these PCa have DNA repair defects that render them clinically more radiosensitive. TMPRSS2-ERG is therefore unlikely to be a predictive factor for IGRT response.”