The usual way of establishing the risk of prostate cancer is by testing blood for the presence of the protein prostate-specific antigen (PSA) or by way of biopsy. However, the major drawback with both of these approaches is that the results of these tests are ambiguous as they do not correlate well with the actual risk of dying from the disease. This means that there is uncertainty for both doctors and patients on how best to proceed.
A new study carried out by scientists at Weill Cornell Medical College has shown that the presence of a second protein (ERG) in prostate tissue biopsies substantially increases the likelihood of cancer developing. This discovery should help doctors to decide which men are at risk of developing prostate cancer and how best to monitor them.
The researchers found that 53 per cent of men whose prostate biopsies showed the presence of ERG protein developed invasive prostate cancer, compared to 35 per cent of men whose biopsies were ERG-negative. All of the biopsies were classified as having high-grade prostatic intraepithelial neoplasia (HGPIN), which are lesions that may develop into cancer.
The findings of this study mean that those men with ERG-positive HGPIN biopsies could in future be closely monitored and treated whilst those whose biopsies are ERG-negative could avoid unnecessary further biopsies.
The study’s senior investigator, Dr. Mark Rubin, said, “This study is the largest ever conducted that focuses on looking at HGPIN and ERG in a systematic way. We found that more than half of patients with these biomarkers go on to develop prostate cancer, and that is a significant finding which we now want to test in a prospective clinical trial.”
"What this study shows is that not all HGPIN is equal -- that is, clinically significant. When confirmed in larger studies, testing for ERG in these precancerous lesions may change clinical practice in how men are evaluated with abnormal biopsies and may lead to earlier cancer detection," he added.
The study co-author Dr. Christopher Barbieri, a research fellow in the Department of Urology at Weill Cornell Medical College said,” About 1.3 million men will have a prostate biopsy each year, and this biopsy will be HGPIN-positive in more than 100,000 men. While HGPIN can be a precursor to prostate cancer, it's not really clear how often men with HGPIN will develop prostate cancer, or how quickly. Because of this uncertainty, urologists aren't entirely clear on how they should follow men with HGPIN. The guidelines used to be that all men with HGPIN should get an immediate repeat biopsy, but now some experts suggest waiting six months, or a year, or not re-biopsy at all.”
"Now we have shown that men with HGPIN that expressed ERG were at higher risk for developing prostate cancer. This finding could potentially give urologists a better idea of who needs a repeat biopsy, and who is more likely to be at lower risk,"
"We are now in an era of precision medicine -- where looking at cancers at a molecular level will give us crucial information that we can use to decide on the right clinical course for individual patients," Dr. Rubin says. "In that same light, findings in this study point to a potential advance in early assessment and treatment of prostate cancers."
The findings of the study are reported in the Journal of Clinical Oncology.
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