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.
Testing capacity has been boosted by inclusion of commercial laboratory companies and the fact that the virus spreads less easily than SARS-CoV-2
At the start of the SARS-CoV-2 pandemic, clinical laboratories were unprepared for unprecedented testing volumes. Fast forward to today, and the monkeypox outbreak has some clinical laboratory managers and pathologists wondering if they might again be faced with a surge in demand for monkeypox testing.
The good news is that so far the supply of tests appears adequate, especially compared to the early days of COVID-19.
“We’ve always had more capacity than we have had tests coming in,” Walensky noted. “To date, we’ve used about 14% to 20% of our capacity.”
During a hearing before the Senate Health, Education, Labor, and Pensions Committee on the current state of monkeypox testing capacity in the US, Rochelle Walensky, MD (above), Director at the CDC said, “We worked through commercial labs to expand testing across the country and simultaneously [offered] outreach and education to providers, clinicians, patients, and public health.” At the moment, access to clinical laboratory testing for monkeypox appears stable, but that could change as demand grows. (Photo copyright: CDC.)
Capacity Sits at 80,000 Tests Per Week in the US
When the monkeypox outbreak began, US medical laboratories could run 6,000 tests per week. At the time, this was more than sufficient, according to a White House press briefing.
However, since then, demand for testing has increased across the country to 80,000 tests per week. As part of that effort, the CDC partnered with five commercial laboratories to expand access to testing, according to the federal Department of Health and Human Services (HHS), Dark Daily reported in August.
Testing capacity also has kept up with demand thanks to biology. Monkeypox, which is in the same orthopoxvirus family of viruses as smallpox, has proven far less virulent than COVID-19, so fewer people are getting infected.
FDA Advises Against Monkeypox Saliva Test
Another boost to capacity in the future may come from new types of monkeypox tests.
Wired reported on Aug. 1 that Flow Health—a California company already distributing COVID-19 tests—has developed a monkeypox test that can detect the virus in saliva. This test would require patients to spit into a tube for a sample, and as such could be distributed for at-home use.
However, in a report released on July 15, the US Food and Drug Administration (FDA) advised providers to only take testing samples from lesions caused by the rash associated with monkeypox infection. The FDA stated that there is currently no clinical data to support the use of other monkeypox tests like Flow Health’s.
Monkeypox Testing Resources Scarce in Some Areas
At the moment, clinical laboratory testing capacity seems stable, however, roadblocks are appearing that may disrupt the availability of monkeypox tests for patients.
Although bringing on five commercial laboratories has increased US testing capacity, MedTech Dive reported on Aug. 10 that for some hospitals and laboratories, resources for monkeypox testing are scarce.
“Right now, there’s a lot of confusion in the community about where to get tested, where can people find treatment,” Robert Pitts, MD, an Infectious Diseases Specialist at Bellevue, told MedTech Dive. “There’s just no clear guidance because I think a lot of the different facilities and healthcare systems in New York are still trying to patch together pathways. … We’ve had to borrow space, borrow staff, which has been really, really challenging.”
During August, Bellevue took two primary care providers out of their normal clinical responsibilities to instead focus on monkeypox. And Pitts found himself dedicating four to five hours of his time to monkeypox-related issues, MedTech Dive reported.
“And so, I’m using my own time, because it’s a crisis, to respond to it,” he said.
The US healthcare system has been somewhat more efficient at getting monkeypox tests out to clinical laboratories than was the case with COVID-19. Moreover, new tests may be on the way. However, roadblocks exist that must be overcome to ensure monkeypox testing capability will meet growing demand.
Should the test prove clinically viable, it could lead to new biomarkers for eye disease diagnostics and a new assay for clinical laboratories
Scientists at Flinders University in Australia have developed a genetic blood or saliva test that, they say, is 15 times more effective at identifying individuals at high risk of glaucoma than current medical laboratory tests.
If so, this discovery could lead to new biomarkers for diagnostic blood tests that help medical professionals identify and treat various diseases of the eye. Their test also can be performed on saliva samples. The researchers plan to launch a company later in 2022 to generate an accredited test that can be used in clinical trials.
“Early diagnosis of glaucoma can lead to vision-saving treatment, and genetic information can potentially give us an edge in making early diagnoses, and better treatment decisions,” said lead researcher Owen Siggs, PhD, Associate Professor, College of Medicine and Public Health at Flinders University, in a university press release.
Flinders University researchers have been collaborating with scientists at the QIMR Berghofer Medical Research Institute and other research institutes worldwide for some time to identify genetic risk factors for glaucoma, the press release noted.
“In the cross-sectional study of monogenic and polygenic variants related to the disease, the new genetic test was evaluated in 2,507 glaucoma patients in Australia and 411,337 people with or without glaucoma in the UK. The test, conducted using a blood or saliva sample, could potentially detect individuals at increased risk before irreversible vision loss happens,” Medical Device Network reported.
“Genetic testing is not currently a routine part of glaucoma diagnosis and care, but this test has the potential to change that,” said Jamie Craig, PhD, (above), Distinguished Professor, College of Medicine and Health at Flinders University in Australia and senior author of the study, in a press release. “We’re now in a strong position to start testing this in clinical trials,” he added. This is yet another example of how new research is identifying a novel biomarker that could be incorporated into a clinical laboratory test. (Photo copyright: Flinders University.)
Who Is at Risk for Glaucoma?
Glaucoma is a group of eye diseases that are typically caused by a buildup of pressure within the eye. The eyeball contains and produces a fluid called aqueous humour which provides nutrition to the eye and keeps the eye in a proper pressurized state. Any excess of this fluid should be automatically released via a drainage canal called the trabecular meshwork.
But that’s not always the case. When the fluid cannot drain properly, intraocular pressure is created. Most forms of glaucoma are characterized by this pressure, which can damage the optic nerve and eventually cause vision loss and even blindness. Treatments for the disease include medications, laser treatments, and surgery.
Anyone can develop glaucoma, but according to the Mayo Clinic, individuals at higher risk of the disease include:
Individuals over the age of 60.
Those with a family history of glaucoma.
People of African, Asian, or Hispanic descent.
Patients with certain medical conditions, such as diabetes, heart disease, high blood pressure, and sickle cell anemia.
Those with corneas that are thin in the center.
Individuals who have had a past eye injury or certain types of eye surgery.
People who have taken corticosteroid medications, especially eyedrops, for an extended period of time.
Glaucoma is the second leading cause of blindness worldwide, particularly among the elderly. When diagnosed early, the condition is manageable, but even with treatment, about 15% of glaucoma patients become blind in at least one eye within 20 years.
According to the federal Centers for Disease Control and Prevention (CDC), approximately three million Americans are living with glaucoma. The disease often has no early symptoms, which is why it is estimated that about 50% of individuals who have glaucoma do not realize they have the illness.
Thus, a clinically-viable genetic test that is 15 times more likely to identify people at risk for developing glaucoma in its early stages would be a boon for ophthalmology practices worldwide and could save thousands from going blind.
More research and clinical trials are needed before the Flinders University genetic test for glaucoma becomes available. But the discovery alone demonstrates the importance of continuing research into identifying novel biomarkers that could be incorporated into useful clinical laboratory diagnostic tests.
