MADRID, SPAIN (UroToday.com) - Prognostic variables to help differentiate indolent tumors from more aggressive tumors amongst patients with low- and intermediate-risk prostate could help to guide treatment decisions and post-treatment monitoring. This study examined the use of the TERT hypermethylated oncological region (THOR) as a diagnostic and prognostic marker in prostate cancer.
Hypermethylation of THOR has previously been reported by the authors as being associated with telomerase activation in cancer, and has been shown to be an effective prognostic marker in pediatric cancers. Using TCGA data, the authors found that high THOR methylation was present in adult telomerase-dependent cancers as well, including prostate cancer. Using an international multi-institutional cohort of 267 patients undergoing radical prostatectomy, the authors found THOR hypermethylation correlated with Gleason score, tumor invasiveness, and lymph node positivity. It was also associated with an absolute decrease in biochemical progression-free survival (bPFS) of 18% at 5 years (64% vs 82% for hypomethylated cancers) and 48% at 8 years (34% vs 82%). This difference in bPFS was seen even when the analysis was limited to patients with Gleason 6 or 7 (3+4) disease, with THOR methylation predictive of a 3.7-fold increased risk of bPFS on multivariate analysis (95% CI 1.18-11.5, p=0.03).
The authors conclude that THOR hypermethylation may be used as a prognostic variable to predict outcomes in patients with low or intermediate grade prostate cancer following radical prostatectomy. In future studies the authors would like to examine its use prior to treatment in prostate cancer diagnosis and monitoring.
Presented by Ricardo Leão,1,2,3 Pedro Castelo-Branco,1,5 Tatiana Lipman,1 Brittany Campbell,1 Aryeh Price,1 Cindy Zhang,1 Dave Lee,1 Sfetan Boerno,6 Ana Gomes,3 Hugo Coelho,3 Robert G Bristow,4 Michal Schweiger,6 Robert J Hamilton,2 Alexandre Zlotta,2 Arnaldo Figueiredo,3 Helmut Klocker,7 Holger Sueltman,8 and Uri Tabori1 at the 30th Annual European Association of Urology (EAU) Congress - March 20 - 24, 2015 - IFEMA - Feria de Madrid - Madrid, Spain
1Arthur and Sonia Labatt Research Center, The Hospital for Sick Children, University of Toronto; 2Division of Urology, Princess Margaret Cancer Center, University of Toronto, 8Serviço de Urologia e Transplantação Renal, CHUC, Coimbra, Portugal; 1Radiation Medicine Program, Princess Margaret Cancer Center, University of Toronto; 5Regenerative Medicine Program, University of Algarve, Portugal; 6Max Planck Institute for Molecular GeneKcs, Berlin, Germany; 7Department of Urology, Medical University of Innsbruck, Austria; 8Cancer Genome Research, Heidelberg; Germany
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Reported by Timothy Ito, MD, medical writer for UroToday.com