Accurate blood-based clinical laboratory testing for cancer promises to encourage more people to undergo early screening for deadly diseases
One holy grail in diagnostics is to develop less-invasive specimen types when screening or testing for different cancers. This is the motivation behind the creation of a new assay for colorectal (colon) cancer that uses a blood sample and that could be offered by clinical laboratories. The data on this assay and its performance was featured in a recent issue of the New England Journal of Medicine(NEJM).
The company developing this new test recognized that more than 50,000 people will die in 2024 from colon cancer, according to the American Cancer Society. That’s primarily because people do not like colonoscopies even though the procedure can detect cancer in its early stages. Similarly, patients tend to find collecting their own fecal samples for colon cancer screening tests to be unpleasant.
But the clinical laboratory blood test for cancer screening developed by Guardant Health may make diagnosing the deadly disease less invasive and save lives. The test “detects 83% of people with colorectal cancer with specificity of 90%,” a company press release noted.
“Early detection could prevent more than 90% of colorectal cancer-related deaths, yet more than one third of the screening-eligible population is not up to date with screening despite multiple available tests. A blood-based test has the potential to improve screening adherence, detect colorectal cancer earlier, and reduce colorectal cancer-related mortality,” the study authors wrote in the NEJM.
As noted above, this is the latest example of test developers working to develop clinical laboratory tests that are less invasive for patients, while equaling or exceeding the sensitivity and specificity of existing diagnostic assays for certain health conditions.
“I do think having a blood draw versus undergoing an invasive test will reach more people, My hope is that with more tools we can reach more people,” Barbara H. Jung, MD (above), President of the American Gastroenterological Association, told NPR. Clinical laboratory blood tests for cancer may encourage people who do not like colonoscopies to get regular screening. (Photo copyright: American Gastroenterology Association.)
Developing the Shield Blood Test
Colorectal cancer is the “third most common cancer among men and women in the US,” according to the American Gastrological Association (AGA). And yet, millions of people do not get regular screening for the disease.
To prove their Shield blood test, Guardant Health, a precision oncology company based in Redwood City, Calif., enrolled more than 20,000 patients between the ages of 45-84 from across the US in a prospective, multi-site registrational study called ECLIPSE (Evaluation of ctDNA LUNAR Assay In an Average Patient Screening Episode).
“We assessed the performance characteristics of a cell-free DNA (cfDNA) blood-based test in a population eligible for colorectal cancer screening. The coprimary outcomes were sensitivity for colorectal cancer and specificity for advanced neoplasia (colorectal cancer or advanced precancerous lesions) relative to screening colonoscopy. The secondary outcome was sensitivity to detect advanced precancerous lesions,” the study authors wrote in the NEJM.
In March, Guardant completed clinical trials of its Shield blood test for detecting colorectal cancer (CRC) in men and women. According to the company press release, the test demonstrated:
83% sensitivity in detecting individuals with CRC.
88% sensitivity in detecting pathology-confirmed Stages I-III.
Additionally, the Shield test showed sensitivity by stage of:
65% for pathology-confirmed Stage I,
55% for clinical Stage I,
100% for Stage II, and
100% for Stage III.
“The results of the study are a promising step toward developing more convenient tools to detect colorectal cancer early while it is more easily treated,” said molecular biologist and gastroenterologist William M. Grady, MD, Medical Director, Gastrointestinal Cancer Prevention Program at Fred Hutchinson Cancer Center and corresponding author of the ECLIPSE study in the press release. “The test, which has an accuracy rate for colon cancer detection similar to stool tests used for early detection of cancer, could offer an alternative for patients who may otherwise decline current screening options.”
Are Colonoscopies Still Needed?
“More than three out of four Americans who die from colorectal cancer are not up to date with their recommended screening, highlighting the need for a more convenient and less invasive screening method that can overcome barriers associated with traditional options,” Daniel Chung, MD, gastroenterologist at Massachusetts General Hospital and Professor of Medicine at Harvard Medical School, said in the Guardant press release.
Barbara H. Jung, MD, President of the American Gastroenterological Association, says that even if Guardant’s Shield test makes it to the public the “dreaded colonoscopy” will still be needed because the procedure is used to locate and test polyps. “And when you find those you can also remove them, which in turn prevents the cancer from forming,” she told NPR.
There is hope that less invasive clinical laboratory testing will encourage more individuals to get screened for cancer earlier and regularly, and that the shift will result in a reduction in cancer rates.
“Colorectal cancer is highly treatable if caught in the early stages,” said Chris Evans, President of the Colon Cancer Coalition, in the Guardant press release.
Guardant Health’s ECLIPSE study is a prime example of the push clinical laboratory test developers are making to create user-friendly test options that make it easier for patients to follow through with regular screening for early detection of diseases. It echoes a larger effort in the medical community to think outside the box and come up with creative solutions to reach wider audiences in the name of prevention.
As doctors become more familiar with using biomarkers to monitor Crohn’s disease, clinical laboratories may play a greater role in that process
New evidence-based guidelines from the American Gastroenterological Association (AGA) that call for using specific biomarkers to help manage Crohn’s disease (CD) may decrease the number of invasive procedures patients must undergo and increase the role clinical laboratories play in monitoring the disease.
The new AGA guidelines “recommend using the C-reactive protein (CRP) biomarker in blood and the fecal calprotectin (FCP) biomarker in stool to measure inflammation levels and assess whether Crohn’s disease is in remission or active,” Medical News Today reported.
Crohn’s disease is a chronic inflammatory bowel disease (IBD) that causes inflammation in the digestive tract, primarily in the small and large intestine. The cause of the disease is unknown, but genetics may play a role.
Typically, CD patients must undergo repeated colonoscopies to monitor the disease’s progression or remission. This has long been standard practice. Now, however, “AGA recommends the use of biomarkers in addition to colonoscopy and imaging studies,” according to an AGA news release. This hints at a greater role for clinical laboratories in helping physicians manage patients with Crohn’s Disease.
“Patients’ symptoms do not always match endoscopic findings, so biomarkers are a useful tool to understand and monitor the status of inflammation and guide decision making in patients with Crohn’s disease,” said gastroenterologist Siddharth Singh, MD, Assistant Professor of Medicine at UC San Diego Health and a co-author of the new AGA guidelines.
The AGA’s new guidelines demonstrate how medical science is generating new insights about how multiple biomarkers can be associated for diagnosis/management of a disease in ways that change the standard of care, particularly if it can reduce invasive procedures for the patient by the use of less invasive methods (such as a venous blood draw instead of a colonoscopy).
“Based on this guideline, biomarkers are no longer considered experimental and should be an integral part of inflammatory bowel disease care,” Ashwin Ananthakrishnan MD (above), a gastroenterologist at Massachusetts General Hospital and co-author of the guidelines, told Medical News Today. Under the new AGA guidelines, clinical laboratories will play a greater role in helping patients monitor their disease. (Photo copyright: Massachusetts General Hospital.)
Patient’s Needs Determine Biomarker vs Endoscopy Monitoring
AGA’s new guidelines could give patients a more comfortable, cost-effective, and possibly more efficient treatment plan to manage their Crohn’s disease. That’s even true if a patient’s Crohn’s disease is in remission.
With these new guidelines, Crohn’s disease patients in remission would only need their biomarkers to be checked every six to 12 months. Patients with active symptoms would need their biomarkers checked roughly every two to four months.
Biomarker testing can be seen as a useful addition to Crohn’s disease care rather than a full replacement of other forms of care. For example, the new AGA guidelines do not fully omit imaging studies and colonoscopies from treatment. Rather, they are recommended in treatment plans based on the patient’s needs.
In their Gastroenterology paper, the AGA authors wrote, “A biomarker-based monitoring strategy involves routine assessment of symptoms and noninvasive biomarkers of inflammation in patients with CD in symptomatic remission to inform ongoing management. In this situation, normalization of biomarkers is an adequate treatment target—asymptomatic patients with normal biomarkers would continue current management without endoscopy, whereas those with elevated biomarkers would undergo endoscopy.”
Fecal Matter Biomarkers
In speaking with Medical News Today on the benefits of using fecal biomarkers to assess a patient’s disease maintenance, gastroenterologist Jesse Stondell, MD, an Associate Clinical Professor at UC Davis Health, said, “If we start a patient on therapy, they’re not responding appropriately, they’re still having a lot of symptoms, we can check that fecal calprotectin test and get a very quick sense of if things are working or not.
“If the calprotectin is normal, it could be reassuring that there may be other reasons for their symptoms, and that the medicine’s working. But if they have symptoms, and a calprotectin is elevated, that’s a signal that we have to worry the medicine is not working. And that we need to change therapy in that patient,” he added.
“This is a win for Crohn’s disease patients,” Ashwin Ananthakrishnan, MD, a gastroenterologist at Massachusetts General Hospital and co-author of the AGA’s new guidelines, told Medical News Today. “Biomarkers are usually easier to obtain, less invasive, more cost-effective than frequent colonoscopies, and can be assessed more frequently for tighter disease control and better long-term outcomes in Crohn’s disease.”
Clinical laboratories should expect these guidelines to increase demand for the processing of blood or fecal matter biomarker testing. As Crohn’s disease monitoring becomes more dependent on biomarker testing, clinical labs will play a critical role in that process.
