Results from a huge study have shown the fight against cancer may have an incredible new weapon: a simple blood that test can detect multiple different types of cancer before they even show symptoms.
The Pathfinder study, which enrolled 6,600 adults aged 50 and over, offered the blood test to each adult and mixed it with current screening methods to identify whether the Galleri test could find cancers that were evading other methods. Developed by GRAIL, the test is hoped to allow detection of cancer in its early stages when it is most vulnerable to treatment. Cancers that are detected in stage I and II have a significantly higher survival rate, making diagnostics one of the most powerful tools in preventing the estimated 10 million cancer deaths worldwide.
Out of the total sample, the test found cancer in about 1 percent of people. Within those, some types of cancer were found for which there are no current screening methods, suggesting those cancers could have developed for significantly longer before being detected. When paired with other screening methods, the numbers began to skyrocket.
“When added to standard of care screening, MCED [Multi-Cancer Early Detection] testing more than doubled the number of cancers detected compared to standard screening alone. In fact, Galleri detected more cancers than all U.S. Preventive Services Task Force-recommended standard single cancer screenings combined. These included Stage I cancers of the liver, small intestine, and uterus, and Stage II pancreatic, bone, and oropharyngeal cancers,” said Dr Jeffrey Venstrom, chief medical officer at GRAIL, in a statement.
“This is particularly notable given the PATHFINDER population was heavily screened with higher-than-average rates for mammography, colonoscopy, and low-dose CT lung scans.”
Out of the total sample, 35 participants were diagnosed with 36 cancers; 25 of these were cancers that do not have currently established screening tests. Almost half of the non-recurrent cancers were found in either stage I or II, making it likely that effective treatment can be found, and some of the cancers detected were pancreatic and ovarian, which are typically found at a late stage with poor prognoses.
Once tallied, the cancer signal testing had a 97 percent accuracy in identifying a cancer's origin, a high number compared to standard-of-care screening available. The participants also noted their relatively low anxiety surrounding the screening process following the study, which is a strong advantage of newer cancer screens, such as liquid biopsies. Fewer than 1 percent of people received a false positive result.
“Every year, we lose more than 600,000 loved ones to cancer in the U.S. alone. Unfortunately, the burden of cancer will grow with the demographic tidal wave, as the absolute risk of developing any cancer increases as we get older,” said Dr Josh Ofman, president at GRAIL, in a statement.
“Bending the cancer mortality curve will require earlier detection of more cancer. However, a world with more single cancer screening tests is simply clinically and economically untenable as each single cancer screening test has a false positive rate of 5-10 percent. We need to expand from screening for individual cancers to also screening individuals for cancer. We believe MCED tests can enable this paradigm shift by finding more types of cancer at earlier stages with a single blood test.”