Two articles discussing the development of new genetic tests which could potentially be used to detect and determine aggressive prostate cancers were published in the May 2nd and May 15th issues of the Zerohour Newsletter of the Project to End Prostate Cancer.
The biggest problem facing men who have been diagnosed with prostate cancer is to determine whether the cancer is potentially aggressive and therefore requires treatment or whether it can be subject to “active surveillance”. PSA values alone will not answer this question. However, genetic changes or biomarkers are being actively sought by researchers to help determine the aggressive nature of the cancer. Three such genes are named ERG, ETV1 and PTEN. Researchers at Stanford University and Abbott Molecular are working to develop a molecular assay to detect rearrangements of the ERG and ETV1 genes and measure loss of the PTEN gene. A study published in the British Journal of Cancer evaluated 308 prostate cancer patients who were treated conservatively. “Those who did not show abnormal ERG/ETV1 genetic changes with no PTEN gene loss had excellent prognosis, as evidenced by an 85 percent survival rate after 11 years. Men who showed PTEN gene loss in the absence of the gene rearrangements had a poor survival rate of 13.7 percent. The study showed the promise of the new biomarkers to identify patients who would benefit most from intensive therapies.”
In another study, researchers at the Mayo Clinic have found that changes to the “on-off” switches of genes occur early in the development of prostate cancer and could be used as biomarkers to detect the disease months or even years earlier than current approaches. “These biomarkers — known as DNA methylation profiles — also can predict if the cancer is going to recur and if that recurrence will remain localized to the prostate or, instead, spread to other organs. The study, published in the journal Clinical Cancer Research, is the first to evaluate the methylation changes that occur across the entire human genome in prostate cancer. The discovery could someday help physicians diagnose prostate cancer earlier and make more effective treatment decisions to improve cure rates and reduce deaths. It also points to the development of new drugs that reverse the DNA methylation changes, turning the “off” switch back “on” and returning the genetic code to its normal, noncancerous state.”