New technique could allow emergency responders to determine severity of LVO stroke while patient is still in the ambulance
Researchers at Brigham and Women’s Hospital in Massachusetts say they have developed a clinical laboratory test that can quickly determine whether a patient is experiencing one of the deadliest types of strokes, known as an ischemiclarge vessel occlusion (LVO) stroke. The development team believes this new assay could be deployed as a point-of-care test to enable faster diagnosis of stroke events.
The test combines measurement of two blood plasma biomarkers with an established clinical score used by clinicians and EMS personnel to assess stroke severity. Compared with current approaches, their technique more accurately differentiates LVO strokes from other types of strokes, making it more likely that patients receive appropriate treatment in a timely manner, the researchers said in a Brigham news release.
Dark Daily has long predicted that advances in technology and computing power would make it possible for pathologists and clinical laboratory scientists to combine multiple established biomarkers (individually not associated with the disease state targeted) with other clinical and patient data to create the ability to make an accurate and earlier diagnosis.
Ultimately, Brigham’s research could “aid in the development of a point‐of‐care diagnostic test capable of guiding prehospital LVO stroke triage,” wrote Joshua Bernstock, MD, PhD, Clinical Fellow in Neurosurgery at Brigham and Women’s Hospital, lead author of the study, and colleagues.
“We have developed a game-changing, accessible tool that could help ensure that more people suffering from stroke are in the right place at the right time to receive critical, life-restoring care,” said Joshua Bernstock, MD, PhD (above), Clinical Fellow in Neurosurgery at Brigham and Women’s Hospital and lead author of the Brigham study that developed the clinical laboratory test that the researchers say can enable emergency caregivers to determine quickly and accurately if a patient is having an ischemic large vessel occlusion (LVO) stroke. (Photo copyright: Brigham and Women’s Hospital.)
Early Identification of LVO Stroke
As explained in the news release, an LVO stroke is a type of ischemic stroke caused by obstruction in a major brain artery. The researchers noted that LVO strokes account for “62% of poststroke disabilities and 96% of poststroke death.”
These strokes are readily treatable using endovascular thrombectomy (EVT), in which the blockages are surgically removed, the news release note. However, the researchers observed that EVT “requires specialized teams and equipment, limiting its availability to comprehensive stroke centers and other EVT‐capable centers.”
This can lead to delays as patients are transferred to those facilities, worsening outcomes and increasing the risk of death, the researchers wrote in Stroke: Vascular and Interventional Neurology. So, early identification of LVO stroke is key to ensuring patients receive timely treatment.
Identifying False Negatives/Positives
One challenge, the news release notes, is that brain bleeds (hemorrhagic stroke) can present similar symptoms, yet require “vastly different” treatment.
“A growing body of work has, therefore, evaluated prehospital stroke assessment scales in an effort to identify LVO strokes in the field,” the researchers wrote. “However, such severity scales lack the sensitivity and specificity required for triaging LVO patients with confidence, resulting in false negatives in patients with LVO as well as false positives in patients with stroke mimics or hemorrhagic stroke.”
As explained by EMS Aware, these assessment scales, such as FAST-ED (field assessment stroke triage for emergency destination) and RACE (rapid arterial occlusion evaluation), attempt to determine the severity of a stroke by assigning scores based on symptoms such as facial palsy, arm weakness, and speech difficulties.
To develop their test, Bernstock and colleagues proposed combining the scales with measurement of two blood proteins:
In their study, they attempted to validate cutoff values for the biomarkers and scales.
To do so, the researchers analyzed data from 323 patients admitted to a Florida hospital with suspected stroke between May 2021 and August 2022. Each was assigned to one of four diagnostic categories based on clinical data from their medical records, which included results of computed tomography (CT scan) or magnetic resonance angiography (MRA). The diagnostic categories included:
The patients were assessed using five stroke severity scales. The researchers used frozen blood samples from the patients to measure the biomarkers. They then used this data to determine the likelihood of LVO stroke and compared the results with the diagnoses as determined by the clinical data.
“Combinations of the blood biomarkers with the scales FAST‐ED or RACE showed the best performance for LVO detection, with a specificity of 94% (for either scale combination) and a sensitivity of 71% for both scales,” the researchers wrote.
Sensitivity was higher in patients who presented within the first six hours from onset of symptoms.
“Critically, application of the biomarker and stroke scale algorithms ruled out all patients with hemorrhage,” the researchers wrote. However, they also suggested that their algorithm could be adjusted to enable early identification of hemorrhagic stroke.
The researchers noted that they chose biomarker cutoffs to maximize specificity, so “a certain number of LVOs are missed. However, as such patients default into ‘standard‐of‐care’ triaging pathways, such a decision is unlikely to represent much clinical risk.”
Testing in the Field
The Brigham researchers used established biological biomarkers combined with modern computing—in combination with the scores from a field assessment test—to develop their new clinical laboratory test that identifies the type of stroke.
Their next step is to carry out “another prospective trial to measure the test’s performance when used in an ambulance,” the news release states. “They have also designed an interventional trial that leverages the technology to expedite the triage of stroke patients by having them bypass standard imaging and move directly to intervention.”
“In stroke care, time is brain,” Bernstock said. “The sooner a patient is put on the right care pathway, the better they are going to do. Whether that means ruling out bleeds or ruling in something that needs an intervention, being able to do this in a prehospital setting with the technology that we built is going to be truly transformative.”
More research and clinical studies are needed. However, the fact that the Brigham team wants to deploy this approach in ambulances is an indication that there is high clinical value from this approach.
Clinical pathologists and medical laboratory managers will want to watch the ongoing development and deployment of this new assay, whether it is run in near-patient settings or core clinical laboratories in support of patients presenting in emergency departments.
Scientists reported positive Phase 1 trial results of their “intratumoral microdevice” in patients with glioma tumors
Here is an example of new microtechnology which has the potential to greatly shorten the time and improve the ability of physicians to determine which anti-cancer drug is most effective for an individual patient’s glioblastoma. As it is further developed, this technology could give anatomic pathologists and clinical laboratories an increased role in assessing the data produced by microdevices and helping physicians determine the most appropriate anti-cancer drug for specific patients.
In a news release, researchers at Brigham and Women’s Hospital (BWH) in Boston said they have developed an implantable “intratumoral microdevice” (IMD) that functions as a “lab in a patient,” capable of gauging the effectiveness of multiple drugs that target brain tumors. In a Phase 1 clinical trial, they tested the IMD on six patients with glioma tumors.
“In order to make the greatest impact on how we treat these tumors, we need to be able to understand, early on, which drug works best for any given patient,” study co-author Pier Paolo Peruzzi, MD, PhD, told the Harvard Gazette. “The problem is that the tools that are currently available to answer this question are just not good enough. So, we came up with the idea of making each patient their own lab, by using a device which can directly interrogate the living tumor and give us the information that we need.”
Peruzzi is Principal Investigator at the Harvey Cushing Neuro-Oncology Laboratories and Assistant Professor of Neurosurgery at Harvard Medical School.
“Our goal is for the placement of these devices to become an integral part of tumor surgery,” said Pier Paolo Peruzzi, MD PhD (above) of Brigham and Women’s Hospital and Harvard Medical School in an article he co-wrote for Healio. “Then, with the data that we have from these microdevices, we can choose the best systemic chemotherapy to give to that patient.” Pathologists and clinical laboratories may soon play a role in helping doctors interpret data gathered by implantable microdevices and choose the best therapies for their patients. (Photo copyright: Dana-Farber Cancer Institute.)
New Perspective on Tumor Treatments
In a news story he co-wrote for Healio, Peruzzi explained that the microdevice—about the size and shape of a grain of rice—contains up to 30 tiny reservoirs that the researchers fill with the drugs they want to test. Surgeons implant the device during a procedure to remove the tumors.
The surgery takes two to three hours to perform, and during that time, the device releases “nanodoses” of the drugs into confined areas of the tumor. Near the end of the procedure, the device is removed along with tissue specimens. The researchers can then analyze the tissue to determine the effectiveness of each drug.
“This is not in the lab, and not in a petri dish,” Peruzzi told Harvard Gazette. “It’s actually in real patients in real time, which gives us a whole new perspective on how these tumors respond to treatment.”
The Healio story notes that gliomas are “among the deadliest brain cancers and are notoriously difficult to treat.” With current approaches, testing different therapies has posed a challenge, Peruzzi wrote.
“Right now, the only way these drugs are tested in patients is through what are called window-of-opportunity studies, where we give one drug to the patient before we resect the tumor and analyze the effect of the drug,” he said. “We can only do this with one drug at a time.”
Determining Safety of Procedure
The primary goal of the Phase 1 trial was to determine the safety of the procedure, Peruzzi noted. “To be in compliance with standard clinical practice and minimize risks to the patients, we needed to integrate the placement and retrieval of the device during an otherwise standard operation.”
The trial consisted of three men and three women ranging from 27 to 86 years old, with a median age of 76. Five were diagnosed with glioblastoma and one with grade 4 astrocytoma.
“None of the six enrolled patients experienced adverse events related to the IMD, and the exposed tissue was usable for downstream analysis for 11 out of 12 retrieved specimens,” the researchers wrote in Science Translational Medicine. They noted that application of the IMD added about 32 minutes to the time required for the surgery, equating to a cost increase of $7,800.
One drug they tested was temozolomide (TMZ), “the most widely used agent in this patient population,” they wrote. “Several patients in our trial received it systemically, either before or after IMD insertion, as part of the standard of care. Thus, although our trial was not designed to choose chemotherapy agents based on IMD data, we still could compare the observed clinical-radiological response to systemic TMZ with the patient-specific response to TMZ in the IMD-exposed tissue.”
One patient, the researchers noted, had not benefited from the drug “in concordance with the poor tissue response observed in the IMD analysis.” But in another patient, a 72-year-old woman, “IMD analysis showed a marked response to TMZ,” and she survived for 20 months after receiving the treatment “with radiological evidence of tumor response. This was despite having a subtotal tumor resection, in itself an unfavorable prognostic factor. The patient expired because of an unrelated cardiovascular event, although she had remained neurologically stable.”
Drug Duration Limitation
One limitation of the study was that testing the device during the tumor removal procedure limited the duration of the drug treatments, Peruzzi said. The Harvard Gazette noted that following their initial study, the researchers were testing a variation of the procedure in which the device is implanted three days before the main surgery in a minimally invasive technique. This gives the drugs more time to work.
Cancer researchers have theorized that common treatments for tumors can impair the immune system, Peruzzi wrote in Healio. “One thing we want to look at is which drugs can kill the tumor without killing the immune system as well,” he noted.
Future studies will determine the effectiveness of implanting microdevices into tumors to test therapies in vivo. Should they become viable, clinical laboratories and anatomic pathologists will likely be involved in receiving, interpreting, storing, and transmitting the data gathered by these devices to the patient’s doctors.
Some hospital organizations are pushing back, stating that the new regulations are ‘too rigid’ and interfere with doctors’ treatment of patients
In August, the Biden administration finalized provisions for hospitals to meet specific treatment metrics for all patients with suspected sepsis. Hospitals that fail to meet these requirements risk the potential loss of millions of dollars in Medicare reimbursements annually. This new federal rule did not go over well with some in the hospital industry.
Sepsis kills about 350,000 people every year. One in three people who contract the deadly blood infection in hospitals die, according to the Centers for Disease Control and Prevention (CDC). Thus, the federal government has once again implemented a final rule that requires hospitals, clinical laboratories, and medical providers to take immediate actions to diagnose and treat sepsis patients.
The effort has elicited pushback from several healthcare organizations that say the measure is “too rigid” and “does not allow clinicians flexibility to determine how recommendations should apply to their specific patients,” according to Becker’s Hospital Review.
Perform blood tests within a specific period of time to look for biomarkers in patients that may indicate sepsis, and to
Administer antibiotics within three hours after a possible case is identified.
It also mandates that certain other tests are performed, and intravenous fluids administered, to prevent blood pressure from dipping to dangerously low levels.
“These are core things that everyone should do every time they see a septic patient,” said Steven Simpson, MD, Professor of medicine at the University of Kansas told Fierce Healthcare. Simpson is also the chairman of the Sepsis Alliance, an advocacy group that works to battle sepsis.
Simpson believes there is enough evidence to prove that the SEP-1 guidelines result in improved patient care and outcomes and should be enforced.
“It is quite clear that this works better than what was present before, which was nothing,” he said. “If the current sepsis mortality rate could be cut by even 5%, we could save a lot of lives. Before, even if you were reporting 0% compliance, you didn’t lose your money. Now you actually have to do it,” Simpson noted.
“We are encouraged by the increased attention to sepsis and support CMS’ creation of a sepsis mortality measure that will encourage hospitals to pay more attention to the full breadth of sepsis care,” Chanu Rhee, MD (above), Infectious Disease/Critical Care Physician and Associate Hospital Epidemiologist at Brigham and Women’s Hospital told Healthcare Finance. The new rule, however, requires doctors and medical laboratories to conduct tests and administer antibiotic treatment sooner than many healthcare providers deem wise. (Photo copyright: Brigham and Women’s Hospital.)
Healthcare Organizations Pushback against Final Rule
“By encouraging the use of broad spectrum antibiotics when more targeted ones will suffice, this measure promotes the overuse of the antibiotics that are our last line of defense against drug-resistant bacteria,” the AHA’s letter states.
In its recent coverage of the healthcare organizations’ pushback to CMS’ final rule, Healthcare Finance News explained, “The SEP-1 measure requires clinicians to provide a bundle of care to all patients with possible sepsis within three hours of recognition. … But the SEP-1 measure doesn’t take into account that many serious conditions present in a similar fashion to sepsis … Pushing clinicians to treat all these patients as if they have sepsis … leads to overuse of broad-spectrum antibiotics, which can be harmful to patients who are not infected, those who are infected with viruses rather than bacteria, and those who could safely be treated with narrower-spectrum antibiotics.”
CMS’ latest rule follows the same evolutionary path as previous federal guidelines. In August 2007, CMS announced that Medicare would no longer pay for additional costs associated with preventable errors, including situations known as Never Events. These are “adverse events that are serious, largely preventable, and of concern to both the public and healthcare providers for the purpose of public accountability,” according to the Leapfrog Group.
In 2014, the CDC suggested that all US hospitals have an antibiotic stewardship program (ASP) to measure and improve how antibiotics are prescribed by clinicians and utilized by patients.
Research Does Not Show Federal Sepsis Programs Work
He points to analysis which showed that though use of broad-spectrum antibiotics increased after the original 2015 SEP-1 regulations were introduced, there has been little change to patient outcomes.
“Unfortunately, we do not have good evidence that implementation of the sepsis policy has led to an improvement in sepsis mortality rates,” Rhee told Fierce Healthcare.
Rhee believes that the latest regulations are a step in the right direction, but that more needs to be done for sepsis care. “Retiring past measures and refining future ones will help stimulate new innovations in diagnosis and treatment and ultimately improve outcomes for the many patients affected by sepsis,” he told Healthcare Finance.
Sepsis is very difficult to diagnose quickly and accurately. Delaying treatment could result in serious consequences. But clinical laboratory blood tests for blood infections can take up to three days to produce a result. During that time, a patient could be receiving the wrong antibiotic for the infection, which could lead to worse problems.
The new federal regulation is designed to ensure that patients receive the best care possible when dealing with sepsis and to lower mortality rates in those patients. It remains to be seen if it will have the desired effect.
Radiological method using AI algorithms to detect, locate, and identify cancer could negate the need for invasive, painful clinical laboratory testing of tissue biopsies
This will be of interest to histopathologists and radiologist technologists who are working to develop AI deep learning algorithms to read computed tomography scans (CT scans) to speed diagnosis and treatment of cancer patients.
“Researchers used the CT scans of 170 patients treated at The Royal Marsden with the two most common forms of retroperitoneal sarcoma (RPS)—leiomyosarcoma and liposarcoma—to create an AI algorithm, which was then tested on nearly 90 patients from centers across Europe and the US,” the news release notes.
The researchers then “used a technique called radiomics to analyze the CT scan data, which can extract information about the patient’s disease from medical images, including data which can’t be distinguished by the human eye,” the new release states.
The research team sought to make improvements with this type of cancer because these tumors have “a poor prognosis, upfront characterization of the tumor is difficult, and under-grading is common,” they wrote. The fact that AI reading of CT scans is a non-invasive procedure is major benefit, they added.
“This is the largest and most robust study to date that has successfully developed and tested an AI model aimed at improving the diagnosis and grading of retroperitoneal sarcoma using data from CT scans,” said the study’s lead oncology radiologist Christina Messiou, MD, (above), Consultant Radiologist at The Royal Marsden NHS Foundation Trust and Professor in Imaging for Personalized Oncology at The Institute of Cancer Research, London, in a news release. Invasive medical laboratory testing of cancer biopsies may eventually become a thing of the past if this research becomes clinically available for oncology diagnosis. (Photo copyright: The Royal Marsden.)
Study Details
RPS is a relatively difficult cancer to spot, let alone diagnose. It is a rare form of soft-tissue cancer “with approximately 8,600 new cases diagnosed annually in the United States—less than 1% of all newly diagnosed malignancies,” according to Brigham and Women’s Hospital.
In their published study, the UK researchers noted that, “Although more than 50 soft tissue sarcoma radiomics studies have been completed, few include retroperitoneal sarcomas, and the majority use single-center datasets without independent validation. The limited interpretation of the quantitative radiological phenotype in retroperitoneal sarcomas and its association with tumor biology is a missed opportunity.”
According to the ICR news release, “The [AI] model accurately graded the risk—or how aggressive a tumor is likely to be—[in] 82% of the tumors analyzed, while only 44% were correctly graded using a biopsy.”
Additionally, “The [AI] model also accurately predicted the disease type [in] 84% of the sarcomas tested—meaning it can effectively differentiate between leiomyosarcoma and liposarcoma—compared with radiologists who were not able to diagnose 35% of the cases,” the news release states.
“There is an urgent need to improve the diagnosis and treatment of patients with retroperitoneal sarcoma, who currently have poor outcomes,” said the study’s first author Amani Arthur, PhD, Clinical Research Fellow at The Institute of Cancer Research, London, and Registrar at The Royal Marsden NHS Foundation Trust, in the ICR news release.
“The disease is very rare—clinicians may only see one or two cases in their career—which means diagnosis can be slow. This type of sarcoma is also difficult to treat as it can grow to large sizes and, due to the tumor’s location in the abdomen, involve complex surgery,” she continued. “Through this early research, we’ve developed an innovative AI tool using imaging data that could help us more accurately and quickly identify the type and grade of retroperitoneal sarcomas than current methods. This could improve patient outcomes by helping to speed up diagnosis of the disease, and better tailor treatment by reliably identifying the risk of each patient’s disease.
“In the next phase of the study, we will test this model in clinic on patients with potential retroperitoneal sarcomas to see if it can accurately characterize their disease and measure the performance of the technology over time,” Arthur added.
Importance of Study Findings
Speed of detection is key to successful cancer diagnoses, noted Richard Davidson, Chief Executive of Sarcoma UK, a bone and soft tissue cancer charity.
“People are more likely to survive sarcoma if their cancer is diagnosed early—when treatments can be effective and before the sarcoma has spread to other parts of the body. One in six people with sarcoma cancer wait more than a year to receive an accurate diagnosis, so any research that helps patients receive better treatment, care, information and support is welcome,” he told The Guardian.
According to the World Health Organization, cancer kills about 10 million people worldwide every year. Acquisition and medical laboratory testing of tissue biopsies is both painful to patients and time consuming. Thus, a non-invasive method of diagnosing deadly cancers quickly, accurately, and early would be a boon to oncology practices worldwide and could save thousands of lives each year.
Best of all, the researchers say the test could provide an inexpensive means of early diagnosis. This assay could also be used to monitor how well patients respond to cancer therapy, according to a news release.
The protein had previously been identified as a promising biomarker and is readily detectable in tumor tissue, they wrote. However, it is found in extremely low concentrations in blood plasma and is “well below detection limits of conventional clinical laboratory methods,” they noted.
To overcome that obstacle, they employed an ultra-sensitive immunoassay known as a Simoa (Single-Molecule Array), an immunoassay platform for measuring fluid biomarkers.
“We were shocked by how well this test worked in detecting the biomarker’s expression across cancer types,” said lead study author gastroenterologist Martin Taylor, MD, PhD, Instructor in Pathology, Massachusetts General Hospital and Harvard Medical School, in the press release. “It’s created more questions for us to explore and sparked interest among collaborators across many institutions.”
“We’ve known since the 1980s that transposable elements were active in some cancers, and nearly 10 years ago we reported that ORF1p was a pervasive cancer biomarker, but, until now, we haven’t had the ability to detect it in blood tests,” said pathologist and study co-author Kathleen Burns, MD, PhD (above), Chair of the Department of Pathology at Dana-Farber Cancer Institute and a Professor of Pathology at Harvard Medical School, in a press release. “Having a technology capable of detecting ORF1p in blood opens so many possibilities for clinical applications.” Clinical laboratories may soon have a new blood test to detect multiple types of cancer. (Photo copyright: Dana-Farber Cancer Institute.)
Simoa’s Advantages
In their press release, the researchers described ORF1p as “a hallmark of many cancers, particularly p53-deficient epithelial cancers,” a category that includes lung, breast, prostate, uterine, pancreatic, and head and neck cancers in addition to the cancers noted above.
“Pervasive expression of ORF1p in carcinomas, and the lack of expression in normal tissues, makes ORF1p unlike other protein biomarkers which have normal expression levels,” Taylor said in the press release. “This unique biology makes it highly specific.”
Simoa was developed at the laboratory of study co-author David R. Walt, PhD, the Hansjörg Wyss Professor of Bioinspired Engineering at Harvard Medical School, and Professor of Pathology at Harvard Medical School and Brigham and Women’s Hospital.
The Simoa technology “enables 100- to 1,000-fold improvements in sensitivity over conventional enzyme-linked immunosorbent assay (ELISA) techniques, thus opening the window to measuring proteins at concentrations that have never been detected before in various biological fluids such as plasma or saliva,” according to the Walt Lab website.
Simoa assays take less than two hours to run and require less than $3 in consumables. They are “simple to perform, scalable, and have clinical-grade coefficients of variation,” the researchers wrote.
Study Results
Using the first generation of the ORF1p Simoa assay, the researchers tested blood samples of patients with a variety of cancers along with 406 individuals, regarded as healthy, who served as controls. The test proved to be most effective among patients with colorectal and ovarian cancer, finding detectable levels of ORF1p in 58% of former and 71% of the latter. Detectable levels were found in patients with advanced-stage as well as early-stage disease, the researchers wrote in Cancer Discovery.
Among the 406 healthy controls, the test found detectable levels of ORF1p in only five. However, the control with the highest detectable levels, regarded as healthy when donating blood, “was six months later found to have prostate cancer and 19 months later found to have lymphoma,” the researchers wrote.
They later reengineered the Simoa assay to increase its sensitivity, resulting in improved detection of the protein in blood samples from patients with colorectal, gastroesophageal, ovarian, uterine, and breast cancers.
The researchers also employed the test on samples from 19 patients with gastroesophageal cancer to gauge its utility for monitoring therapeutic response. Although this was a small sample, they found that among 13 patients who had responded to therapy, “circulating ORF1p dropped to undetectable levels at follow-up sampling.”
“More Work to Be Done”
The Simoa assay has limitations, the researchers acknowledged. It doesn’t identify the location of cancers, and it “isn’t successful in identifying all cancers and their subtypes,” the press release stated, adding that the test will likely be used in conjunction with other early-detection approaches. The researchers also said they want to gauge the test’s accuracy in larger cohorts.
“The test is very specific, but it doesn’t tell us enough information to be used in a vacuum,” Walt said in the news release. “It’s exciting to see the early success of this ultrasensitive assessment tool, but there is more work to be done.”
More studies will be needed to valid these findings. That this promising new multi-cancer immunoassay is based on a clinical laboratory blood sample means its less invasive and less painful for patients. It’s a good example of an assay that takes a proteomic approach looking for protein cancer biomarkers rather than the genetic approach looking for molecular DNA/RNA biomarkers of cancer.