Genetic test that analyzes DNA to identify men at greatest risk for developing the disease could become common clinical laboratory screen for cancer
Researchers in the UK believe a common spit test can be more accurate at determining which men are more likely to develop prostate cancer than the clinical laboratory prostate-specific antigen (PSA) blood test currently used by the National Health Service (NHS) for that diagnosis.
During a recent study, scientists at the Institute of Cancer Research, London (ICR), found that germline DNA extracted from saliva, which was then used to derive polygenic risk scores for cancer, resulted in a higher percentage of participants “found to have clinically significant disease” than the percentage that would have been identified with the use of PSA or MRI.
The salvia test works by analyzing men’s DNA to find out if they are genetically pre-disposed to developing the disease. Men who find out they are likely to develop prostate cancer can then pursue further testing and scans.
“The test assesses 130 genetic variants to provide a risk score for prostate cancer, which is the second most common cause of cancer deaths in men in the UK,” The Guardian reported.
The study found that 187 of the men in the study had prostate cancer. According to the American Cancer Society, one in eight men will be diagnosed with prostate cancer in their lifetime.
“We can identify men at risk of aggressive cancers who need further tests and spare the men who are at lower risk from unnecessary treatments,” said study leader Rosalind Eeles, PhD, of the ICR London, in The Guardian.
“With this test, it could be possible to turn the tide on prostate cancer,” Rosalind Eeles, PhD, of the Institute of Cancer Research, London, told the BBC. (Photo copyright: Prostate Cancer UK.)
Landmark Discovery
Michael Inouye, PhD, professor of systems genomics and population health at the University of Cambridge, told the BBC that researchers will look back on this study “as a landmark.” He also acknowledged that it would be a long road before widespread implementation of the test.
While some sources call the ICR’s test promising, they also acknowledge it may only have a modest effect and that there may be possible racial disparities in the findings. The study was primarily based on people with European ancestry. According to Prostate Cancer UK, black men in the UK have double the risk of developing the disease. A similar trend can be observed in the US, Statistica reported.
Dusko Ilic, PhD, professor in stem cell sciences at King’s College London, told the BBC that there was “no direct evidence” of these findings having an effect on survival or quality of life. He stressed the need for more studies to better assess the value of the test.
The salvia test is expected to be included in Prostate Cancer UK’s TRANSFORM trial, a $58 million research program partly funded by the NHS to determine the best way to screen for cancer in the UK.
Effect on Clinical Pathologists
Prostate cancer is expected to surge in the US over the next 15 years, according to UC Davis Health. Thus, pathologists should expect more men to seek ways to assess their risk. Pathologists would be wise to educate themselves fully on new and emerging tests and tools to best meet the needs of their patients.
Given the publicity generated by former President Biden’s announcement that he has an advanced case of prostate cancer, clinical laboratories should also expect more patients to request diagnostic tests that either screen for or confirm the presence of the disease.
Researchers in Sweden develop urine test that more effectively screens for prostate cancer than standard PSA test
Clinical laboratories may soon have a new inexpensive, non-invasive urine test to screen for prostate cancer that produces superior results compared to the standard PSA test.
An international team of scientists led by researchers at the Karolinska Institutet in Sweden found they could use machine learning to not only accurately identify the presence of a new set cancer biomarkers in urine samples but also determine the stage or grade of the cancer.
“There are many advantages to measuring biomarkers in urine,” said Mikael Benson, principal researcher in the Department of Clinical Science, Intervention and Technology at Karolinska Institutet and senior investigator for the study, in a news release. “It’s non-invasive and painless and can potentially be done at home. The sample can then be analyzed using routine methods in clinical labs.”
“New, more precise biomarkers than PSA can lead to earlier diagnosis and better prognoses for men with prostate cancer,” said Mikael Benson, principal researcher at Karolinska Institutet and senior investigator for the study, in a news release. “Moreover, it can reduce the number of unnecessary prostate biopsies in healthy men.” (Photo copyright: Karolinska Institutet.)
New Prostate Cancer Biomarkers
According to the American Cancer Society, there will be approximately 313,780 new cases of prostate cancer diagnosed this year in the US with about 35,770 deaths due to the disease. About one in eight US men will be diagnosed with prostate cancer in their lifetime, and the lifetime risk of dying from prostate cancer is one in 44 men.
“Early cancer diagnosis is crucial but challenging owing to the lack of reliable biomarkers that can be measured using routine clinical methods. The identification of biomarkers for early detection is complicated by each tumor involving changes in the interactions between thousands of genes. In addition to this staggering complexity, these interactions can vary among patients with the same diagnosis as well as within the same tumor,” the researchers wrote in Cancer Research.
The scientists “hypothesized that reliable biomarkers that can be measured with routine methods could be identified by exploiting three facts:
The same tumor can have multiple grades of malignant transformation;
These grades and their molecular changes can be characterized using spatial transcriptomics; and,
These changes can be integrated into models of malignant transformation using pseudotime models to prioritize the genes that were most correlated with malignant transformation.”
To perform their study, the scientists analyzed the mRNA activity of cells in prostate tumors to construct digital models of prostate cancer. These models were then examined using machine learning, a type of artificial intelligence (AI), to locate specific proteins that could be used as biomarkers.
The researchers evaluated these new biomarkers in urine, blood, and tissue samples from more than 2,000 prostate cancer patients along with a control group. The team’s final calculations found the results of the urine test surpassed the current PSA test traditionally used for diagnosing prostate cancer.
“Prostate cancer can be effectively identified by analyzing the expression of candidate biomarkers in urine,” lead study author Martin Smelik, PhD student at Karolinska Institutet, told Fox News. “This approach outperforms the current blood tests based on PSA, but at the same time keeps the advantages of being non-invasive, painless, and relatively cheap.”
Advancements over Traditional PSA Test
Although the prostate-specific antigen (PSA) test typically used by doctors to diagnose prostate cancer can screen for the disease and monitor its progression, it has limitations.
“While PSA is an incredibly sensitive tool for issues related to the prostate, it is not specific to prostate cancer,” Matthew Abramowitz, MD, associate professor in the Department of Radiation Oncology at the Sylvester Comprehensive Cancer Center, University of Miami Miller School of Medicine, told Fox News. “The techniques proposed in the current study suggest the promise of identifying specific cancer markers in the urine, minimizing some of the specificity concerns associated with PSA.”
“This study highlights the power of machine learning applied to patient data in identifying breakthroughs that can help us diagnose cancer earlier, when our treatments are most effective,” Timothy Showalter, MD, a radiation oncologist at UVA Health in Virginia, told Fox News. “Prostate cancer screening has not seen a transformative advance in decades, and current approaches still rely on the PSA blood test, which is known to have low specificity for clinically significant cancers.”
“Overall, this study demonstrates the diagnostic potential of combining spatial transcriptomics, pseudotime, and machine learning for prostate cancer, which should be further tested in prospective studies,” the researchers wrote.
The Karolinska Institutet team is planning large-scale clinical trials as the next phase of their exploration.
OPKO Health’s 4Kscore test predicts the rate of high-risk prostate cancer and may become a useful business case study for other labs developing proprietary diagnostic tests
Clinical laboratories and biotech companies with new medical laboratory tests are struggling to win coverage by Medicare and private payers. How big is this problem? There are currently tens of thousands of molecular diagnostic assays and genetic tests offered for clinical use.
Any lab company seeking to obtain an appropriate Current Procedural Terminology (CPT) code, favorable coverage guidelines, and adequate reimbursement from health insurers for its new lab test faces three big challenges, and they are related. First, payers are simply overwhelmed with requests to review new genetic tests. The flood of new test submissions exceeds the capability of payers to respond.
Most Payers May Not Have Right Scientific Expertise to Evaluate Genetic Tests
As healthcare systems make patient safety a greater priority, the public reporting of pathology errors in Canada has no comparable track record in the United States
Errors in anatomic pathology testing in the Canadian provinces of Nova Scotia and Saskatchewan made media headlines this summer. In each case, it was just a limited number of cases where errors at pathology labs resulted in inaccurate diagnoses and, in at least one case, a needless mastectomy for a patient.
At a time when health systems in Canada, the United States, and other developed nations are giving great emphasis to patient safety, disclosure of life-changing diagnostic errors to patients is appropriate. Consumers are holding physicians—including surgical pathologists—to a higher standard of care. (more…)
