Predicting Prostate Cancer Progression as a Function of ERG Status, Race & Obesity in a Longitudinal Patient Cohort
European Urology Focus 2017, Cullen et al. –BERG, LLC, collaborates with the Walter Reed National Military Medical Center and Center for Prostate Disease Research (CPDR) to investigate a large, racially diverse military population demonstrating that ERG tumor gene expression is a useful predictor of progression amongst Caucasian patients, but not for African Americans.
Authors: Jennifer Cullen, Denise Young, Yongmei Chen, Michael Degon, James Farrell, Jason Sedarsky, Wagner Baptiste, Philip Rosen, Vladimir Tolstikov, Michael A. Kiebish, Jacob Kagan, Sudhir Srivastava, Huai-Ching Kuo, Joel T Moncur, Inger L Rosner, Niven R. Narain, Viatcheslav R. Akmaev, Gyorgy Petrovics, Albert Dobi, David G McLeod, Shiv Srivastava, and Isabell A Sesterhenn
Prostate cancer is the second leading cause of death in American men. The most common genetic alteration is in the gene ERG, which can create pro-cancer fusion genes. Previous studies have shown differences in ERG fusion genes in various racial groups. The ERG status of a patient is important to determine so patients can be treated by the most effective therapy, as several drugs target ERG and its associated signaling pathways. The goals of this study, spearheaded by CPDR, were to determine if the presence or absence of ERG in prostate cancer patients is predictive of disease progression, and if race also had an effect on ERG expression and disease progression. Over 900 military healthcare patient whole prostate samples were analyzed, of which 36% were African American, and 64% were Caucasian American. ERG was found to be lower in African American patients, compared with Caucasian Americans. ERG-positive tumors in Caucasian Americans were associated with younger age, lower obesity and a more favorable score of disease severity. ERG-negativity in Caucasian Americans was associated with greater odds of recurrent disease, but interestingly, there was no association between ERG and disease in African American patients. ERG-positive surgical margin (the healthy tissue surrounding a tumor biopsy) was predictive of disease recurrence in African American, but not Caucasian patients. The data also demonstrated a trend between obesity and ERG negativity in Caucasian patients. This study provides evidence that ERG status and obesity may be an indicator for predicting disease progression after prostate cancer surgery in Caucasian American men.