Discovery could lead to new clinical laboratory testing for cancer screening in new mothers
Any clinical laboratory test that returns unexpected results is worth looking into more deeply. Such was the case with a recent study conducted by the National Institutes of Health (NIH), which investigated cases of pregnant women who received “unusual” results to prenatal lab tests conducted at a dozen labs in North America.
Following cancer screening protocols that included rapid whole-body magnetic resonance imaging, NIH scientists discovered “previously undetected cancers in 48.6% of pregnant people who had abnormal results for prenatal cell-free DNA (cfDNA) testing used to screen for chromosomal disorders in the fetus,” according to an NIH news release.
“They looked like healthy young women, and they reported themselves as being healthy,” Diana Bianchi, MD, head of the Prenatal Genomics and Therapy Section for the Medical Genetics Branch at the NIH’s National Human Genetics Research Institute, and senior author of the government study, told the Associated Press (AP).
While cfDNA tests are not diagnostic, pathologists and clinical laboratory managers involved in genetic testing are likely familiar with them. The blood tests are used by expectant mothers to assess risk of a fetus with an abnormal number of chromosomes that could suggest disorders such as Down Syndrome, according to ARUP Laboratories.
Unexpected results from tests draw attention. This one seems to have a chance to get more traction with labs because the results point to a prenatal test having some success predicting cancer, even if incidentally.
“[The study participants] and their care providers need to take the results seriously and have additional testing because in that population there is a 48% risk of cancer,” Diana Bianchi, MD, senior author of the NIH study, told the AP. (Photo copyright: National Institutes of Health.)
Cancer Found in about Half of Those with Abnormal cfDNA
The NIH researchers started a long-term study, called IDENTIFY, to learn more about abnormal cfDNA results that could suggest cancer. Study participants must be:
Pregnant or postpartum with no known cancer.
Recipients of “unusual clinical cfDNA-sequencing results or results that are non-reportable (fetal aneuploidy status could not be assessed) from one of 12 different commercial laboratories,” they wrote in NEJM.
For the study’s initial cohort of 107 participants, researchers repeated cfDNA sequencing testing and coordinated standard medical diagnostic tests (such as Pap smears) and whole-body magnetic resonance imaging.
52 women (48.6%) were found to have “hidden cancers.”
32 had blood cancers.
20 had solid tumors in the breast, bile duct, colon, pancreas, lung, kidney, bone, and adrenal gland.
13 of the 20 with solid tumors were able to access “potentially curative treatments.”
55 women did not have cancer and may have obtained an unreliable cfDNA result.
“In this study, 48.6% of participants who received unusual or nonreportable clinical cfDNA-sequencing results had an occult cancer (cancer of unknown primary).
“Further study of DNA-sequencing patterns that are suggestive of occult cancer during prenatal screening is warranted,” the researchers wrote in NEJM.
Follow-Up Testing Needed
Cancers found in the study participants “included colorectal, breast, lung and pancreatic cancers, as well as lymphoma, cholangiocarcinoma and renal carcinoma. The screening test analyzes placental DNA fragments circulating in the maternal bloodstream to identify an extra chromosome or to determine the baby’s sex,” according to the NIH news release.
Bianchi told AP the study results also pointed to a “very chaotic” pattern in DNA-sequencing of women with cancer, and that more research is needed to find out who should be screened for cancer.
Clinical laboratories and pathologists who analyze cfDNA tests could take a leadership role in assessing current standards for the tests, determining how suspicious results are reported, and suggesting needed changes.
“Previously … CDC developed tests for emerging pathogens and then shared those tests with others, and then after that, commercial labs would develop their own tests,” Shah told CNN. “That process took time. Now with these new arrangements, commercial labs will be developing new tests for public health responses alongside CDC, not after CDC.”
In a news release announcing the contract, ARUP Laboratories also characterized the move as a shift for the agency.
“The new contract formalizes ARUP’s relationship with the CDC,” said Benjamin Bradley, MD, PhD, medical director of the ARUP Institute for Research and Innovation in Infectious Disease Genomic Technologies, High Consequence Pathogen Response, Virology, and Molecular Infectious Diseases. “We continue to expand our capabilities to address public health crises and are prepared to scale up testing for H5N1, or develop other tests quickly, should the need arise.”
“To be clear, we have no evidence so far that this [bird flu] virus can easily infect human beings or that it can spread between human beings easily in a sustained fashion,” Jennifer Nuzzo, DrPH (above), Director of the Pandemic Center and Professor of Epidemiology at Brown University School of Public Health, told CNN. “If it did have those abilities, we would be in a pandemic.” Clinical laboratory leaders will recall the challenges at the CDC as it developed its SARS-CoV-2 test early in the COVID-19 pandemic. (Photo copyright: Brown University.)
Missouri Case Raises Concerns
The first human infection of HPAI was reported in late March following a farmer’s “exposure to dairy cows presumably infected with bird flu,” the CDC stated in its June 3, 2024, bird flu Situation Summary. That followed confirmation by the USDA’s Animal and Plant Health Inspection Service (APHIS) of an HPAI outbreak in commercial poultry flocks in February 2022, and the CDC’s confirmation of the first known infections in dairy herds reported on March 25, 2024.
Concerns about the outbreak were heightened in September following news that a person in Missouri had been infected with the virus despite having no known contact with infected animals. CNN reported that it was the 14th human case in the US this year, but all previous cases were in farm workers known to be exposed to infected dairy cattle or poultry.
In a news release, the Missouri Department of Health and Senior Services (DHSS) revealed that the patient, who was not identified, was hospitalized on Aug. 22. This person had “underlying medical conditions,” DHSS reported, and has since recovered and was sent home. Both DHSS and the CDC conducted tests to determine that the virus was the H5 subtype, the news release states.
At present, the CDC states that the public health risk from the virus is low. However, public health experts are concerned that risks could rise as the weather gets cooler, creating opportunities for the virus to mutate “since both cows and other flu viruses will be on the move,” CNN reported.
Concerns over CDC Testing and FDA Oversight
In the months immediately following the first human case of the bird flu virus, Nuzzo was among several public health experts sounding an alarm about the country’s ability to ramp up testing in the face of new pathogens.
“We’re flying blind,” she told KFF Health News in June, due to an inability to track infections in farmworkers. At that time, tests had been distributed to approximately 100 public health labs, but Nuzzo and other experts noted that doctors typically order tests from commercial laboratories and universities.
KFF reported that one diagnostics company, Neelyx Labs, ran into obstacles as it tried to license the CDC’s bird flu test. Founder, CEO, and lead scientist Shyam Saladi, PhD, told KFF that the federal agency had promised to cooperate by facilitating a license and a “right to reference” CDC data when applying for FDA authorization but was slow to come through.
While acknowledging the need for testing accuracy, Greninger contended that the CDC was prioritizing caution over speed, as it did in the early days of the COVID-19 pandemic. “The CDC should be trying to open this up to labs with national reach and a good reputation,” he told KFF.
Another problem, KFF reported, related to the FDA’s new oversight of laboratory developed tests (LDTs), which is causing labs to move cautiously in developing their own tests.
Jennifer Nuzzo, DrPH (above), Director of the Pandemic Center and Professor of Epidemiology at the Brown University School of Public Health co-authored a June 2024 analysis in Health Affairs that called on the CDC to develop “a better testing playbook for biological emergencies.” The authors’ analysis cited earlier problems with the responses to the COVID-19 and mpox (formerly known as monkeypox) outbreaks.
If global surveillance networks have detected a novel pathogen, the authors advise, the US should gather information and “begin examining the existing testing landscape” within the first 48 hours.
Once the pathogen is detected in the US, they continued, FDA-authorized tests should be distributed to public health laboratories and the CDC’s Laboratory Response Network (LRN) laboratories within 48 hours.
Advocates of this approach suggest that within the first week diagnostics manufacturers should begin developing their own tests and the federal government should begin working with commercial labs. Then, within the first month, commercial laboratories should be using FDA-authorized tests to provide “high throughput capacity.”
This may be good advice. Experts in the clinical laboratory and healthcare professions believe there needs to be improvement in how novel tests are developed and made available as novel infectious agents are identified.
Representatives from almost 50 different clinical laboratories, professional associations, and societies came together this week to align efforts to expand the supply and retention of qualified laboratory scientists
FORT WORTH, TEXAS—Last week, representatives from a broad cross section of clinical laboratories, lab and pathology associations, public health laboratories, and lab regulatory bodies gathered specifically to identify ways to expand the number of skilled lab professionals.
COLA organized the “Workforce Action Alliance Summit,” a one-day gathering of key clinical laboratory stakeholders who share a common interest in developing initiatives that would directly increase the number of individuals choosing to pursue a career in laboratory medicine.
This is not a new problem, as the lack of trained laboratory scientists across all scientific disciplines has been acute for many years.
In a communication sent to invited participants, COLA’s CEO, Nancy Stratton, and COO, Kathy Nucifora, described the objective of the summit, writing:
“Clearly a call to collective action is required if we are to address the impending clinical laboratory workforce shortage. The past three years have demonstrated the significance of a resilient laboratory infrastructure, not only for the daily care of millions of Americans, but also during the global pandemic. The numerous efforts currently underway to resolve the shortage are unquestionably a component of the solution. Many, however, believe that these efforts are insufficient to close the gap between the projected number of new entrants into the profession, the rate at which those currently in the profession are departing, and the future demand for laboratory testing.”
Robert L. Michel, Editor-in-Chief of Dark Daily’s sister publication The Dark Report was a participant at COLA’S workforce summit. The Dark Report regularly profiles clinical laboratory organizations that have developed innovative and productive initiatives designed to increase the number of students choosing to train as medical technologists (MTs), clinical laboratory scientists (CLSs), medical laboratory technologists (MLTs) and other skilled lab positions.
In materials distributed at the summit, the ongoing gap between demand for skilled lab professionals and the supply was illustrated thusly:
“The US Department of Labor estimates 320,000 bachelors and associates degreed laboratory professionals are working in the United States. If each of those professionals worked a standard 40-year career, the natural annual attrition of 2.5% would require 8,000 new professionals to maintain their current numbers. This exceeds the current output of accredited educational programs by more than 1,000 annually.”
Case Studies of Success
Over the course of the day, participants at the summit heard about the successes of certain laboratory organizations designed to get more students into training programs, supported by the educational courses required for them to become certified in their chosen area of laboratory medicine. These case studies centered around several themes:
Obtaining funding specifically to establish an MT/CLS training program to increase the number of candidates in a region. One example involved ARUP Laboratories and its success at working with a local Congressional representative to get a $3 million federal grant funded as part of a larger legislative package.
The medical laboratory scientist (MLS) program at Saint Louis University (SLU) worked with Quest Diagnostics to launch an accelerated bachelor’s degree program. The 16-month program combines online academic courses with intensive hands-on learning and clinical experiences in Quest’s Lenexa, Kansas, laboratory. The first students in this accelerated degree program began their studies in the spring semester of 2023.
By rethinking the structure of its existing didactic and experiential learning structure, NorthShore University HealthSystem’s MLS program, located at Evanston Hospital north of Chicago, doubled its enrollment capacity.
During the afternoon, working groups addressed ways that lab organizations can collaborate to increase recruitment and retention of laboratory scientists across all disciplines of lab medicine. This input was synthesized into action planning for the three priorities that can lead to expanding the lab workforce.
By day’s end, several working groups were organized with specific next steps. COLA is taking the lead in managing this initiative and giving it momentum. All clinical laboratory professionals and pathologists are welcome to participate in the Workforce Action Alliance (WAA). Anyone wishing to learn more can contact COLA by clicking here, calling 800-981-9883, or by visiting https://education.cola.org/contact-us-page.
Its low cost may advance liquid biopsy cancer testing used by anatomic pathologists and improve outcomes by speeding time to diagnosis and treatment
Researchers in Japan say they have created a circulating tumor cell (CTC) detection solution that is inexpensive and easy to run. Such a device would be of huge interest to investors and companies wishing to develop clinical laboratory tests that use circulating tumor cells in the blood to identify patients with cancer.
In a proof-of-concept study, researchers at Kumamoto University (KU) in Japan have developed and tested a microfilter device they claim can separate and capture CTCs in blood without large equipment, a KU news release reported.
According to Medgadget, the device is an “inexpensive, convenient, and highly sensitive filter that can successfully work in samples containing as few as five tumor cells in one milliliter of blood and does not require expensive equipment or reagents, unlike certain pre-existing cell capture technologies.”
This Technology Could Give Pathologists a Less-Invasive Cancer Test
As medical laboratory scientists and anatomic pathologists know, a CTC test is less invasive than tissue biopsy, which benefits patients. Furthermore, such a CTC test may enable earlier detection of cancer and start of treatment improving odds for success.
Still, there are many pitfalls to overcome when the challenge is to detect cancer cells in a milliliter (about .03 fluid ounce) of blood. As Medgadget put it, “A needle in a haystack doesn’t even come close.”
“Cancer cell count in the blood of cancer patients is extremely low. If these cells are easily detectable, cancer diagnosis may be possible by simply using a blood test, thus reducing patient burden,” the researchers wrote in their paper.
“This work demonstrates that our microfilter device can accurately detect trace amounts of cancer cells in blood,” said study leader Yuta Nakashima, PhD (above), Associate Professor, Department of Mechanical System Engineering at Kumamoto University, in the news release. “We expect it will be adopted for cancer diagnosis and treatment, including for early diagnosis of cancers that cannot be detected by imaging like CT and PET scans, post-operative follow-up, recurrence monitoring, and tailor-made treatments. In the future, we plan to use blood samples donated by cancer patients to verify the practical and clinical application of the method,” he added. Were it to become available, such a CTC test would be a boon for clinical laboratories and anatomic pathologists engaged in cancer diagnostics and treatment. (Photo copyright: Kumamoto University.)
How Does the CTC Filter Device Work?
The KU scientists created a palm-size “cancer detection device using a microfilter and nucleic acid aptamer,” the paper said, adding:
It includes slits to enable a deformation with force of blood pumping through the device.
As blood flows over the microfilter, cancer cells bind to the nucleic acid aptamer.
Force of blood flow opens microfilter slits, pushing away the healthy cells.
Cancer cells are left on the microfilter.
To test the microfilter the researchers used one milliliter of blood that was “spiked with cancer cells,” according to the paper. Findings include:
Detection of five CTCs in one milliliter of blood.
Blood cell removal rate of 98% suggested “no blood cells were absorbed by the microfilter,” the news release said.
The method “showed higher accuracy than the CellSearch System,” the Talanta paper noted.
The KU research team compared their microfluidic device to CellSearch, an FDA-cleared system for detecting CTCs from a blood sample.
CellSearch enables “identification, isolation, and enumeration of CTCs of epithelial origin,” according to Menarini Silicon Biosystems of Castel Maggiore, Italy. It works from a blood sample of 7.5 millimeters with “high level of sensitivity and specificity,” notes the company’s website.
According to Menarini, labs offering CellSearch CTC testing include:
The UK scientists admit that their research needs further study. Nakashima indicated he plans to test blood samples donated by cancer patients in subsequent device trials.
“Although great progress has been made, there is a long way to go before CTC-based liquid biopsy is widely used as a routine test in clinical application,” the authors of that study noted.
Nevertheless, even with more to do, liquid biopsy testing has come a long way, as multiple Dark Daily eBriefs reported over the years.
If the KU scientists succeed in bringing to market a microfilter that can reduce the cost of CTC detection by clinical laboratories while also improving cancer diagnostics, that will have a huge impact on cancer patients and is worthy of clinical laboratory leaders’ attention.
In the absence of a “gold standard,” researchers are finding a high frequency of false negatives among SARS-CoV-2 RT-PCR tests
Serology tests designed to detect antibodies to the SARS-CoV-2 coronavirus that causes the COVID-19 illness have been dogged by well-publicized questions about accuracy. However, researchers also are raising concerns about the accuracy of molecular diagnostics which claim to detect the actual presence of the coronavirus itself.
“Diagnostic tests, typically involving a nasopharyngeal swab, can be inaccurate in two ways,” said Steven Woloshin, MD, MS, in a news release announcing a new report that “examines challenges and implications of false-negative COVID-19 tests.” Woloshin is an internist, a professor at Dartmouth Institute, and co-director of the Geisel School of Medicine at Dartmouth.
“A false-positive result mistakenly labels a person infected, with consequences including unnecessary quarantine and contact tracing,” he stated in the news release. “False-negative results are far more consequential, because infected persons who might be asymptomatic may not be isolated and can infect others.”
Woloshin led a team of Dartmouth researchers who analyzed two studies from Wuhan, China, and a literature review by researchers in Europe and South America that indicated diagnostic tests for COVID-19 are frequently generating false negatives. The team published their results in the June 5 New England Journal of Medicine (NEJM).
For example, one research team in Wuhan collected samples from 213 hospitalized COVID-19 patients and found that an approved RT-PCR test produced false negatives in 11% of sputum samples, 27% of nasal samples, and 40% of throat samples. Their research was published on the medRxiv preprint server and has not been peer-reviewed.
The literature review Woloshin’s team studied was also published on medRxiv, titled, “False-Negative Results of Initial Rt-PCR Assays for COVID-19: A Systematic Review.” It indicated that the rate of false negatives could be as high as 29%. The authors of the review looked at five studies that had enrolled a total of 957 patients. “The collected evidence has several limitations, including risk of bias issues, high heterogeneity, and concerns about its applicability,” they wrote. “Nonetheless, our findings reinforce the need for repeated testing in patients with suspicion of SARS-Cov-2 infection.”
Another literature review, published in the Annals of Internal Medicine, titled, “Variation in False-Negative Rate of Reverse Transcriptase Polymerase Chain Reaction–Based SARS-CoV-2 Tests by Time Since Exposure,” estimated the probability of false negatives in RT-PCR tests at varying intervals from the time of exposure and symptom onset. For example, the authors found that the median false-negative rate was 38% if a test was performed on the day of symptom onset, versus 20% three days after onset. Their analysis was based on seven studies, five of which were peer-reviewed, with a total of 1330 test samples.
Doctors also are seeing anecdotal evidence of false negatives. For example, clinicians at UC San Diego Health medical center treated a patient with obvious symptoms of COVID-19, but two tests performed on throat samples were negative. However, a third test, using a sample from a bronchial wash, identified the virus, reported Medscape.
Sensitivity and Specificity of COVID-19 Clinical Laboratory Tests
The key measures of test accuracy are sensitivity, which refers to the ability to detect the presence of the virus, and specificity, the ability to determine that the targeted pathogen is not present. “So, a sensitive test is less likely to provide a false-negative result and a specific test is less likely to provide a false-positive result,” wrote Kirsten Meek, PhD, medical writer and editor, in an article for ARUP Laboratories.
“Analytic” sensitivity and specificity “represent the accuracy of a test under ideal conditions in which specimens have been collected from patients with either high viral loads or a complete absence of exposure,” she wrote. However, “sensitivity and specificity under real-world conditions, in which patients are more variable and specimen collection may not be ideal, can often be lower than reported numbers.”
In a statement defending its ID Now molecular point-of-care test, which came under scrutiny during a study of COVID-19 molecular tests by NYU Langone Health, Northwell Health, and Cleveland Clinic, according to MedTech Dive, Abbott Laboratories blamed improper sample collection and handling for highly-publicized false negatives produced by its rapid test. An FDA issued alert about the test on May 14 noted that Abbott had agreed to conduct post-market studies to identify the cause of the false negatives and suggest remedial actions.
Issues with Emergency Use Authorizations
In their NEJM analysis, Woloshin et al point to issues with the FDA’s process for issuing Emergency Use Authorizations (EUAs). For example, they noted variations in how manufacturers are conducting clinical evaluations to determine test performance. “The FDA prefers the use of ‘natural clinical specimens’ but has permitted the use of ‘contrived specimens’ produced by adding viral RNA or inactivated virus to leftover clinical material,” they wrote.
When evaluating clinical performance, manufacturers ordinarily conduct an index test of patients and compare the results with reference-standard test, according to the Dartmouth researchers. For people showing symptoms, the reference standard should be a clinical diagnosis performed by an independent adjudication panel. However, they wrote, “it is unclear whether the sensitivity of any FDA-authorized commercial test has been assessed in this way.” Additionally, a reference standard for determining sensitivity in asymptomatic people “is an unsolved problem that needs urgent attention to increase confidence in test results for contact-tracing or screening purposes.”
“To truly determine false negatives, you need a gold standard test, which is essentially as close to perfect as we can get,” Stephen Rawlings, MD, PhD, (above), a resident physician of internal medicine and infectious diseases fellow at UC San Diego’s Center for AIDS Research (CFAR), who has been working on SARS-CoV-2 test validation since March. “But there just isn’t one yet for coronavirus,” he told Medscape. (Photo copyright: University of California, San Diego.)
Continued adherence to current measures, such as physical distancing and surface disinfection.
Development of highly sensitive and specific tests or combinations of tests to minimize the risk of false-negative results and ongoing transmission based on a false sense of security.
Improved RT-PCR tests and serological assays.
Development and communication of clear risk-stratified protocols for management of negative COVID-19 test results.
“These protocols must evolve as diagnostic test, transmission, and outcome statistics become more available,” they wrote.
Meanwhile, clinical laboratories remain somewhat on their own at selecting which COVID-19 molecular and serology tests they want to purchase and run in their labs. Complicating such decisions is the fact that many of the nation’s most reputable in vitro diagnostics manufacturers cannot produce enough of their COVID-19 tests to meet demand.
Consequently, when looking to purchase tests for SARS-CoV-2, smaller medical laboratory organizations find themselves evaluating COVID-19 kits developed by little-known or even brand-new companies.
