Galleri Blood Test

The Galleri blood test, developed by GRAIL, uses advanced genomic sequencing technology to analyse cell-free DNA in your blood. When cancer cells die, they release fragments of DNA into the bloodstream. The Galleri test examines patterns of chemical modifications (methylation) on this DNA, which can indicate the presence of cancer and even predict where in the body the cancer signal is coming from. This cancer signal origin prediction capability is particularly valuable as it helps guide further diagnostic investigations if needed.

It is important to understand that the Galleri blood test is a screening tool, not a diagnostic test. If a cancer signal is detected, further testing such as imaging or biopsy will be required to confirm a diagnosis. The test has demonstrated strong performance in clinical studies, with a low false positive rate of less than 1 percent in people without cancer. For those with a cancer signal detected, the test accurately predicts the cancer signal origin in approximately 90 percent of cases, helping to direct follow-up investigations.

The Galleri test is intended to complement, not replace, existing single cancer screening programmes such as cervical, breast, and bowel cancer screening. It is most beneficial for individuals aged 50 and above, those with a family history of cancer, or people with lifestyle risk factors. During your appointment at Prema Health, one of our experienced clinicians will take a simple blood sample, discuss your individual risk factors, and explain what to expect from your results. We provide full support throughout the process, including guidance on next steps should any concerning findings arise.

The Galleri blood test screens for signals from more than 50 types of cancer across various body systems. These include common cancers such as breast, bowel, lung, and prostate cancer, as well as many cancers that currently have no recommended screening methods. The test can detect signals from head and neck cancers, gastrointestinal cancers including pancreatic, stomach, oesophageal, and liver cancer, gynaecological cancers such as ovarian and uterine cancer, urological cancers, blood cancers including lymphoma and leukaemia, and many other solid tumours.

Particularly valuable is the test ability to screen for deadly cancers that are often diagnosed late when symptoms finally appear, such as pancreatic cancer, ovarian cancer, and oesophageal cancer. Early detection of these typically hard-to-find cancers can significantly improve treatment options and outcomes. The Galleri test is also beneficial for detecting multiple myeloma, bladder cancer, bile duct cancer, and rare cancers that might otherwise go undetected until advanced stages. By screening for such a wide range of cancers from a single blood sample, the Galleri test provides comprehensive cancer surveillance that goes far beyond traditional screening programmes.