say the authors of new research.
Rachel B. Issaka, MD, MAS, of the Fred Hutchinson Cancer Center, Seattle, presented the clinical data, which was published in The New England Journal of Medicine, at the American Association for Cancer Research annual meeting.
Fred Hutchinson Cancer Center
Dr. Rachel B. Issaka
The authors of the study evaluated the performance of a cfDNA blood-based test in a population eligible for colorectal cancer screening. The researchers found that the test had high sensitivity for the detection of colorectal cancer and high specificity for advanced precancerous lesions.
This novel blood test could improve screening adherence and, ultimately, reduce colorectal cancer-related mortality, Dr. Issaka said during her presentation.
“This test has the potential to help us reach the 80% screening target in colorectal cancer. However, this will depend on many factors, including access, implementation, follow-up colonoscopy, and characteristics of the test,” Dr. Issaka said in an interview.
She added that, when approved for broader use, anyone who wants to use this blood test for colorectal cancer screening should have a frank conversation with their healthcare provider.
“Considering the person’s age, medical history, family history, and any potential symptoms, and how the test performs will dictate if it’s the right test for that person versus another screening strategy,” Dr. Issaka explained.
The Blood Test Detects Colorectal Cancer With High Accuracy
The investigators of the observational ECLIPSE trial evaluated the performance of the cfDNA-based blood test in 7861 individuals who were eligible for colorectal cancer screening. The study population included people from more than 200 rural and urban sites across 34 states, including community hospitals, private practices, gastroenterology clinics, and academic centers. “The study enrolled a diverse cohort that is reflective of the demographics of the intended use population in the US,” Dr. Issaka said during her talk.
The co-primary outcomes of the study were the test’s sensitivity for detecting colorectal cancer and its specificity for identifying advanced neoplasia.
In her presentation, Dr. Issaka highlighted that the test had 83.1% (95% confidence interval [CI], 72.2%-90.3%) sensitivity for the detection of colorectal cancer, meaning that it was able to correctly identify most participants with the disease. The test’s sensitivity was even higher (87.5%; 95% CI, 75.3%-94.1%) for stage I, II, or III colorectal cancer. “These are the stages at which early intervention can have the greatest impact on patient prognosis,” Dr. Issaka said.
Moreover, the blood test showed 89.6% (95% CI, 88.8%-90.3%) specificity for advanced neoplasia, including colorectal cancer and advanced precancerous lesions. The specificity of the test for negative colonoscopy results (no colorectal cancer, advanced precancerous lesions, or nonadvanced precancerous lesions) was 89.9% (95% CI, 89.0%-90.7%).
Dr. Issaka highlighted that this cfDNA assay is the first blood-based test with performance comparable to current guideline-recommended noninvasive options for CRC.
The Blood Test Shows Limited Ability To Detect Advanced Precancerous Lesions
During her presentation, Dr. Issaka acknowledged that the cfDNA-based blood test had a lower sensitivity (13.2%; 95% CI, 11.3%-15.3%) for the detection of advanced precancerous lesions, suggesting that it may be more effective at identifying established cancers than early-stage precancerous changes. Low sensitivity was also observed for high-grade dysplasia (22.6%; 95% CI, 11.4%-39.8%). However, she emphasized that the test could still play a valuable role in a comprehensive screening approach, potentially serving as a first-line tool to identify individuals who would then undergo follow-up colonoscopy.
“Although blood-based tests perform well at finding cancers, they do not do so well at finding precancerous polyps. This is relevant because colorectal cancer is one of the few cancers that we can prevent by finding and removing precancerous polyps,” Folasade P. May, MD, PhD, MPhil, said in an interview.
“Users must also understand that if the test result is abnormal, a colonoscopy is required to look for cancers and polyps that might have caused the abnormal result,” added Dr. May, associate professor at UCLA. She was not involved in the study.
Clinical Implications and Future Steps
According to the study published in the NEJM, colorectal cancer is the third most commonly diagnosed cancer in the United States, and early detection is crucial for effective treatment. However, over a third of eligible individuals are not up to date with recommended screening.
During her talk, Dr. Issaka noted that colonoscopy is the most commonly used screening method for colorectal cancer. What contributes to the low adherence to getting a colonoscopy among the eligible population is that some find it inconvenient, and the test is invasive, she added.
According to Dr. May, the key advantage of cfDNA-based screening is that many people will find it easier to complete a blood test than the currently available screening tests.
“This option may allow us to screen individuals that we have previously struggled to convince to get screened for colorectal cancer,” she said.
In an interview, Dr. Issaka acknowledged that the potential public health impact of any noninvasive screening test depends on how many people with abnormal results complete a follow-up colonoscopy. “This is an important quality metric to track,” she said.
In an interview, Dr. Issaka emphasized that comparing this cfDNA blood test with emerging blood tests and other noninvasive screening strategies will empower patients and clinicians to select the right test at the right time for the right patient.
She added that the study was conducted in an average-risk screening population and that further research is needed to evaluate the test’s performance in higher-risk groups and to assess its real-world impact on screening adherence and colorectal cancer-related outcomes.
Commenting on potential challenges with implementing this cfDNA blood test in clinical practice, Dr. May said, “As we consider incorporating blood-based tests into clinical practice, some challenges include cost, equitable access to tests and follow-up, performance in young adults who are newly eligible for screening, and follow-up after abnormal results.”
She added that, if there is uptake of these tests, it will be important to track how that impacts colorectal cancer screening rates, stage at diagnosis, and whether there is stage migration, incidence, and mortality.
“At this time, I feel that these tests are appropriate for individuals who will not or cannot participate in one of the currently recommended screening tests. These include colonoscopy and stool-based tests, like FIT and FIT-DNA,” Dr. May concluded.
Dr. Issaka reported financial relationships with the National Institutes of Health/National Cancer Institute, American College of Gastroenterology, and Guardant Health Inc. Dr. May reported financial relationships with Takeda, Medtronic, Johnson & Johnson, Saint Supply, Exact Sciences, Freenome, Geneoscopy, Guardant Health, InterVenn, Natura, National Institutes of Health/National Cancer Institute, Veterans Affairs HSR&D, Broad Institute, Stand up to Cancer, and NRG Oncology.
