A study reports high sensitivity and specificity of a cell-free DNA blood-based assay compared to colonoscopy
A cell-free DNA (cfDNA) blood-based assay for the detection of colorectal cancer in an average-risk screening population, showed performance metrics of 83% sensitivity for the detection of colorectal cancer, 90% specificity for advanced neoplasia, and 13% sensitivity for advanced precancerous lesions, as reported in the ECLIPSE study (N Engl J Med. 2024 Mar 14;390(11):973-983).
The prospective, observational, multicenter trial conducted in the U.S compared the performance of the cfDNA blood-based test to standard colonoscopy, which is currently the cornerstone examination of screening programmes for colorectal cancer, revealing the potential of an additional noninvasive screening option. Despite screening programmes have proven to reduce the incidence of colorectal cancer and related mortality, their implementation is uneven across Europe, and adherence rates are still low (Lancet Oncol. 2021 Jul;22(7):1002-1013). Noninvasive blood-based testing alternatives may help to increase the screening uptake among the population at-risk for colorectal cancer.
In the study, a total of 7861 participants - mean age of 60 years, 53.7% were women - were evaluable for final analysis, with completed and valid results from colonscopy and cfDNA blood-based test, including 65 individuals who had a colonoscopy-identified colorectal cancer.
Among those with a detected colorectal cancer, 83.1% had a positive cfDNA test, which indicates that the cfDNA blood-based test had an overall sensitivity of 83.1% (95% confidence interval [CI], 72.2 to 90.3). Sensitivity according to stage trended higher with more advanced cancer, with 42 of 48 stage I, II, or III colorectal cancers identified by the cfDNA blood-based test (sensitivity, 87.5%; 95% CI, 75.3 to 94.1). The test also identified 10 of 10 stage IV colorectal cancers (sensitivity, 100%; 95% CI, 72 to 100), however the small sample did not allow for formal comparison.
A total of 89.6% of the participants without any advanced colorectal neoplasia (colorectal cancer or advanced precancerous lesions) identified on colonoscopy had a negative cfDNA blood-based test, whereas 10.4% had a positive cfDNA blood-based test, indicating a specificity for advanced neoplasia of 89.6% (95% CI, 88.8 to 90.3). A total of 89.9% of the participants who had a negative colonoscopy (defined as no colorectal cancer, advanced precancerous lesions, or nonadvanced precancerous lesions identified on colonoscopy) had a negative cfDNA blood-based test, indicating a specificity for no neoplasia of 89.9%. A false positive rate of 10.1% was observed.
Further studies are needed to understand the effect of this cfDNA blood-based testing in a real-world population and whether its incorporation into existing screening programmes may have a positive impact on screening uptake.
