Cancer recurrence was defined in this study as a rise in prostate specific antigen (PSA) levels after surgery, she said. Rising PSA after removal of the prostate indicates that the cancer is in the process of recurring.
"A methylation test like this could potentially help doctors decide which patients need additional treatment after surgery, and which probably don't," said Cottrell. "The test is based on underlying molecular changes involved in cancer development, and this molecular information is complementary to the clinical and anatomical information currently used to predict recurrence, such as tumor stage and Gleason score."
According to Cottrell, the test will soon be validated in a multi-center trial for submission to the FDA. She also added that while this study analyzed prostatectomy samples, Epigenomics is expanding its research to see if the same results can be obtained from prostate biopsies. "If the test is a strong enough predictor of a good prognosis at the stage of biopsy, men with indolent cancer may not need surgery or radiation at all," she said.
"We know many men have a non-aggressive form of prostate cancer, but because we currently have no way to those patients, only very few are treated with a 'watchful waiting' approach instead of surgery or radiation," she said.
The PITX2 gene is believed to play a role in regulation of hormones, and Epigenomics earlier found that it could also help predict recurrence in breast cancer patients.
In this study, the researchers tested a total of six genetic markers - PITX2 plus five other methylated genes that were identified in tumor tissue taken from patients who recurred shortly after surgery. Hypermethylation of all six markers correlated with poor survival, but using PITX2 alone, the researchers found they could develop a methylation score that defined a good prognosis (with 94 percent PSA
Source:American Association for Cancer Research