Promising results from the PATHFINDER II cancer screening study

Rebecca Kaltman, MD is a board-certified hematologist oncologist. She serves as the Medical Director of the Inova Saville Cancer Screening and Prevention Center.

At Inova Schar Cancer, we’re excited to share encouraging news from a major national research study called PATHFINDER II. This study is helping shape the future of cancer screening – and it’s bringing new hope to patients and families.

A simple blood test with big potential

PATHFINDER II is a large research study that evaluated a new blood test called Galleri®. This test looks for tiny pieces of DNA that cancers can release into the bloodstream. Galleri is one of several similar types of tests that can provide the opportunity to detect cancers for which there is currently no good screening. With this blood test, doctors may be able to identify a cancer that would otherwise not have been found until the cancer had reached a later, and possibly less treatable, stage.

If a signal indicating the possibility of cancer is detected, additional testing is recommended to determine the potential source. This evaluation is guided by Galleri’s test result, which generally suggests one or two sites from which the cancer may be originating.

More than 35,000 adults ages 50 and older joined the study. More than 800 participants were enrolled through Inova Schar Cancer. The PATHFINDER II study has now released its first major results, and the findings are very encouraging.

What did the study find?

• More cancers found, sooner: When the Galleri blood test was added to standard cancer screenings (like mammograms, colonoscopies, pap smears, PSA blood tests and lung scans), doctors found three times more cancers than with standard screening alone
• Earlier detection: Most of the cancers found by the test were at an earlier stage, when treatment is most effective
• Filling the screening gap: About 75% of the cancers detected by Galleri do not have a routine screening test available today
• Accurate and safe: The test was highly accurate, with very few false positive results (a false positive rate of just 0.4%), and fewer than 1% of participants needed an invasive procedure to follow up

Why does this matter?

There are more than 100 types of cancer. Yet, routine screening tests are only available for five kinds of cancer. The other 95+ cancer types – like pancreatic, liver and ovarian, among many others – don’t have reliable screening tests. That means these cancers are often found later, when they are more advanced and treatment is harder. About 70% of all cancer deaths result from types of cancer that do not have a screening test and were caught at a later stage.

PATHFINDER II shows that a simple blood test could help fill this gap, finding cancers earlier and giving patients more options.

It is important to note that Galleri and tests like it can miss cancers frequently, as much as 40 to 60% of the time. While this new category of blood tests is very promising, these tests are not meant to be used in isolation. It is important for everyone to continue to get their routine cancer screening along with any new types of screening like Galleri.

What’s ahead?

PATHFINDER II will continue for several more years. Researchers want to learn how this blood test can work alongside traditional screenings like mammograms and colonoscopies.

In addition, the Inova Saville Cancer Screening and Prevention Center is now part of a Virginia research group that was chosen to be one of nine hubs of the National Cancer Institute’s Cancer Screening Research Network. This network has launched the first randomized controlled study of two multicancer detection (MCD) tests called the Vanguard Study. This study and those that come after will be critical to understanding the impact of MCD testing on cancer detection, healthcare utilization and outcomes compared to those undergoing routine screening.

Learn more

Read the official press release from GRAIL.

The Inova Saville Cancer Screening and Prevention Center is honored to be at the forefront of these exciting developments in cancer screening and early detection.