US: Debate Rages Over Blood Test Offering Promise of Early Cancer Detection – News18

A new $949 Galleri blood test developed by a US-based biotech company offers the promise of early cancer detection, but it has sparked a heated debate among doctors, researchers, and patient advocates. This liquid biopsy can screen for over 50 types of cancers by identifying a shared cancer signal in DNA shed by tumors in the bloodstream, The Wall Street Journal (WSJ) reported.

More than 130,000 of these prescription-only tests have been sold since its availability in June 2021, with Grail, a subsidiary of gene-sequencing company Illumina, responsible for its production. While some doctors and longevity practitioners are including the Galleri test as part of comprehensive health screenings for affluent and health-conscious individuals, concerns persist.

Skeptics argue that there’s insufficient evidence to show that the test prevents cancer deaths, and they warn about the risks of false positive or negative results, the US newspaper said. One study found that over half of those who received a positive result did not have cancer. False positives can lead to unwarranted worry and costly follow-up procedures, while false negatives, which are more likely with this test, may cause patients to skip recommended screenings. In the WSJ report, Dr. Lori Minasian of the National Cancer Institute’s Division of Cancer Prevention advocates caution, particularly for asymptomatic individuals with minimal cancer risk.

Proponents of the Galleri test believe that the benefits of early cancer detection outweigh the potential drawbacks. They argue that making these tests available can increase cancer detection and improve public health. Still, it’s important to note that a positive test result isn’t a diagnosis; it should prompt an evaluation with a healthcare provider. The WSJ report said the test’s commercial availability precedes FDA approval or recommendations from the U.S. Preventive Services Task Force. It’s designed to complement, not replace, recommended cancer screenings and isn’t typically covered by insurance.

Some doctors offer the Galleri test as part of comprehensive physical exams, with prices ranging from $5,000 to $20,000, the report added. About half of their patients inquire about the test, and approximately 10% of them choose to take it. The Galleri test is also making its way into primary and specialty-care centers, often targeting individuals with an elevated cancer risk, such as those over 50 or with genetic risk factors. However, it is not recommended for pregnant individuals, those under 21, or those undergoing active cancer treatment.

Despite the ongoing debate, a company-funded study published in The Lancet reported a false positive rate of less than 1%, with 62% of positive results being incorrect, according to WSJ. Grail is actively working to improve the test’s accuracy. While many individuals like Valerie Caro credit the Galleri test with saving their lives by detecting cancer early, the medical community remains divided on its utility and efficacy. The test’s future depends on further research, FDA evaluation, and the resolution of ongoing controversies surrounding its use.