A new biomarker for prostate cancer has been identified that can be detected in tissue and urine samples. Researchers at Sanford-Burnham Medical Research Institute in Orlando, FL, have found a set of RNA molecules detectable in prostate cancer patients but not in men without this cancer. They publish their findings in The Journal of Molecular Diagnostics.
Currently, screening for prostate cancer consists of testing for high concentrations of prostate-specific antigen (PSA) in blood samples. These PSA tests are often followed by a biopsy to confirm the presence of cancer.
However, the PSA test is considered to be imperfect, and in 2013 the American Urological Association recommended against PSA tests being offered routinely.
Dr. Vipul Patel, medical director of the Global Robotics Institute at Florida Hospital in Orlando, explains:
“While elevated PSA can be an alert to a lethal cancer, it can also detect less aggressive cancers that may never do any harm.
Moreover, only 25% of men with raised PSA levels that have a biopsy actually have prostate cancer. Prostate cancer needs to be screened for; we just need to find a better marker.”
The RNA molecules that the Sanford-Burnham researchers have identified are “long noncoding RNAs” (lncRNAs). Until recently, the usefulness of lncRNAs had not been appreciated by scientists, who dismissed the non-coding molecules as “non-functional noise in the genome.”
lncRNAs are now believed to regulate cellular development. Evidence is also mounting that lncRNAs may contribute to a variety of diseases, including cancer.
lncRNAs were elevated in prostate cancer patient samples across three distinct groups:
- Human prostate cancer cell lines and normal prostate epithelial cells
- Prostate adenocarcinoma tissue samples and matched normal tissue samples
- Urine samples from patients with prostate cancer or benign prostate hypoplasia, and normal healthy individuals.
In each group, prostate cancer patients exhibited higher levels of lncRNAs compared with healthy control subjects.
“We have identified a set of lncRNAs that appear to have an important role in prostate cancer diagnostics,” says Ranjan J. Perera, PhD, associate professor and scientific director of Analytical Genomics and Bioinformatics at Sanford-Burnham’s Lake Nona campus in Orlando.
“The findings advance our understanding of the role of lncRNAs in cancer biology and, importantly, broaden the opportunity to use lncRNAs as biomarkers to detect prostate cancer,” Perera adds.
Because the lncRNAs are easily detected in urine samples, prostate cancer screening could become more accessible than it currently is with blood tests.
- In 2014, more than 230,000 new cases of prostate cancer will be diagnosed among American men
- 1 in 7 American men will get prostate cancer at some point in their life
- 1 in 36 American men will die from the disease.
Dr. Patel concludes:
“There is a tremendous unmet clinical need for better non-invasive screening tools for early detection of prostate cancer to reduce the overtreatment and morbidity of this disease. Our findings represent a promising approach to meet this demand.”
Other recent proposed alternatives to the PSA test include an “electronic noise” designed to differentiate between prostate cancer and benign prostatic hyperplasia, which share similar diagnostic properties.
Earlier this year, Medical News Today reported on the eNose and quoted researchers who claimed the device’s results were on a par with those published for the PSA test and were “achieved rapidly and in a completely noninvasive manner.”