Blood Test for Symptomatic Patients Aims to Revolutionize Cancer Diagnosis

By LabMedica International staff writers
Posted on 05 Jun 2023

Image: Galleri Multi-Cancer Test (Photo courtesy of GRAIL)

Cancer patients generally seek medical attention from a primary care physician only after they begin experiencing related symptoms, such as unexplained weight loss, anemia, or abdominal discomfort. But these symptoms are complex as they can be attributed to various causes. Early detection and intervention of cancer can significantly enhance patient outcomes. Hence, there is a need for innovative tools to speed up cancer diagnosis and potentially eliminate the need for invasive and costly investigations, thus more effectively triaging patients with non-specific cancer symptoms. Now, a novel blood test, capable of detecting over 50 types of cancer, has shown promising results, accurately detecting cancer in two-thirds of more than 5,000 individuals who had consulted their physician due to suspected symptoms. Furthermore, in 85% of these cases, the test accurately identified the original location of the cancer.

The SYMPLIFY study, sponsored by The University of Oxford (Oxford, UK), is the first large-scale evaluation of a multi-cancer early detection (MCED) test from GRAIL, LLC (Menlo Park, CA, USA) among individuals who had consulted their GP due to suspected cancer symptoms. The study enrolled 6,238 participants, aged 18 and above, across England and Wales who were referred for urgent imaging, endoscopy, or other diagnostic methods due to symptoms suggestive of potential gynecological, lung, lower GI or upper GI cancer, or who had presented with non-specific symptoms. All participants provided a blood sample for DNA extraction and testing.

The MCED test from GRAIL detected a cancer signal in 323 individuals, with 244 of these receiving a cancer diagnosis, resulting in a positive predictive value (PPV) of 75.5%, negative predictive value (NPV) of 97.6%, and specificity of 98.4%. The overall sensitivity of the MCED test stood at 66.3%, ranging from 24.2% for stage I cancers to 95.3% for stage IV, and increasing with age and later cancer stage. The overall accuracy of the top CSO prediction following a positive MCED test was 85.2%. The study participants had a mean age of 62.1 years. Encouraged by the study outcomes, GRAIL now aims to broaden its market to include patients demonstrating symptoms linked to cancer, such as unexplained weight loss or abdominal pain.

GRAIL is planning to devise a new test specifically tailored for symptomatic patients, employing the same core technology used in its MCED test. The company hopes to have the new test available in months rather than years. Through a simple blood test, GRAIL aims to minimize reliance on costly scans or invasive biopsies as initial diagnostic procedures for cancer. Medical professionals have expressed enthusiasm about the potential impact of such blood tests in average-risk populations. These tests could serve as a crucial aid in making decisions concerning further diagnostic evaluation for patients. Nevertheless, the efficacy of such blood tests for early cancer detection and their influence on overall patient survival continues to be a topic of debate among clinicians.

“GRAIL’s earlier PATHFINDER study previously demonstrated that adding GRAIL’s MCED testing to standard of care screening more than doubled the number of cancers detected compared with standard screening alone in adults with no symptoms or suspicion of cancer. Now, the SYMPLIFY data confirm the potential benefit of methylation-based MCED blood tests as a diagnostic aid for use in the symptomatic patient population,” said Sir Harpal Kumar, President of GRAIL Europe. “These exciting results will inform our development of an optimized classifier for use in symptomatic patients with a suspicion of cancer.”

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GRAIL, LLC