Grail's Next-Gen Multi-Cancer Test Detects 50 Early-Stage Cancers with 93% Accuracy

Blood Samples

GRAIL published validation data for its multi-cancer early detection blood test. The technology can detect more than 50 different cancer types across all stages. It has a false-positive rate of less than one percent and does all this testing on a single blood sample. It reports that in positive results, it is 93% accurate.

The results of the study were published in Annals of Oncology, describing the results from the company’s foundational Circulating Cell-free Genome Atlas (CCGA) sub-study. The CCGA included more than 15,000 patients who either had cancer or did not. The published results were a sub-study of 6,700 people, showing that Grail’s proprietary targeted methylation technology hit 99.3% specificity or a single low false-positive rate of less than 1%. A related study was published in Cancer Epidemiology, Biomarkers & Prevention.

The CCGA is being conducted at 142 sites in the U.S. and Canada. It is designed to map the broad view of genomic cancer signals in the blood, and then “discover, train and validate” the early detection blood test via three pre-planned sub-studies.

“At Grail, we believe that multi-cancer early detection has the potential to significantly reduce cancer mortality,” said Alex Aravanis, Grail’s co-founder, chief scientific officer and head of R&D. “This is a seminal moment in the field of cancer detection. We’ve built what we believe to be one of the largest clinical study programs ever conducted in genomic medicine, and the data published in Annals of Oncology further support Grail’s approach and commitment to clinical and scientific rigor.”

Most cancers don’t have recommended early screening tests. As a result, by the time they are diagnosed, it can be too late for most effective therapy. Grail’s approach is to sort through a blood sample looking for specific early markers of a variety of cancers. The study suggests that if all cancers currently diagnosed at stage IV were diagnosed earlier, mortality rates could drop by as much as 24%.

The overall detection rate for the substudy for all cancer types was 43.9% across stages I, II and III. Those stages are marked by localized disease that hasn’t spread throughout the body.

In 12 prespecified cancers, the overall detection rate was 67.3%. Those cancers were anus, bladder, colon and rectum, esophagus, head and neck, liver and bile-duct, lungs, lymphoma, ovaries, pancreas and stomach, and plasma cell neoplasms like multiple myeloma. The test appears to become more effective as the cancer progresses, which makes sense. The more advanced the cancer, the more cancer cells, and cancer DNA in the blood. The study reported detecting 39% in stage I, 69% in stage II, 83% in stage III and 92% in stage IV.

The test leverages next-generation sequencing to analyze groups of methyl groups—a carbon atom with three hydrogen atoms attached—latched on to the DNA of cancer cells. Methyl groups help regulate cell activity and gene expression. Found in the bloodstream, the methylation patterns are notably different from DNA from healthy cells.

“Our previous work indicated that methylation-based tests outperform traditional DNA-sequencing approaches to detecting multiple forms of cancer in blood samples,” said co-lead author Geoffrey Oxnard, a medical oncologist at the Dana-Farber Cancer Institute. “The results of this study suggest that such assays could be a feasible way of screening people for a wide variety of cancers.”

Minetta Liu, research chair and professor, Department of Oncology, Mayo Clinic, and co-lead author and investigator in the CCGA study, said, “The promising results from this independent validation data set demonstrate the robustness of the test performance, including its ability to detect multiple cancer types, and its generalizability to broader populations due to a low false-positive rate. In addition, the high accuracy in identifying the anatomic origin of the primary cancer, in conjunction with detection of a positive cancer signal in the blood, will allow providers to efficiently direct next steps for each individual’s diagnostic work-up and subsequent clinical care.”

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