Researchers reported a multi-cancer early detection blood test, when added to recommended screenings for breast, cervical, colorectal, and lung cancers, helped detect more than seven times as many cancers compared to standard screenings alone.
This revelation and others were shared last week when cancer experts from around the world met in Berlin for the annual European Society for Medical Oncology Congress, one of the largest international meetings advancing cancer research and care.
The PATHFINDER 2 study is large, multisite clinical trial determines how well a blood test can detect cancers earlier compared to traditional screening methods. The study has been following thousands of participants for three years to measure how often the test finds cancer, whether people keep up with standard screenings and what happens after early signs of cancer are detected. Results were presented from a pre-specified analysis of more than 25,000 participants with at least 12 months of follow-up.
Over half the cancers found by Galleri® were in early stages when treatment is typically more effective. About three-quarters of the cancers it detected currently have no recommended screening tests. As the largest U.S. study of its kind, PATHFINDER 2 suggests Galleri® could be a powerful new tool in finding more cancers earlier and improving outcomes for more people.

Dr. Charles McDonnell
“Sharing results on this world stage shows the progress we’re making in identifying new ways to detect cancer earlier,” says Dr. Charles McDonnell, radiologist with Sutter Medical Group and an investigator of the study at Sutter Health. “PATHFINDER 2 represents the next step in exploring whether multi-cancer early detection blood tests could become part of everyday care, helping doctors find more cancers at earlier, treatable stages.”
Following the Clues
Cancer can be difficult to detect in its earliest stages. Often it leaves no clear warning signs until it has already advanced, which is why most cancer deaths occur in cancers that lack consistent screenings.
To test a new approach that could be paired with traditional screening methods, Grail launched the PATHFINDER 1 study, one of the first large clinical trials of a MCED blood test. More than 6,600 people nationwide, including over 1,600 at Sutter, took part in the study of Grail’s MCED blood test called Galleri®.
For Louis “Lou” Sall, a 68-year-old Sacramento resident and PATHFINDER 1 participant, the impact was life-changing.
“Because Lou’s head and neck cancer was diagnosed early, he was able to receive chemotherapy and radiation that stopped the disease from spreading to other organs,” said Dr. McDonnell. “Today, he remains in remission for that cancer.”
Stories like Sall’s gave MCEDs the glow of a “crystal ball,” showing what’s possible when cancers are found and treated sooner. Now, PATHFINDER 2 is building on that foundation.

Dr. Natalia Colocci
“As a top enrollment site to PATHFINDER 2, Sutter places its clinicians and patients at the forefront of research that could reshape how cancer is detected,” says Dr. Natalia Colocci, Cancer Service Line medical oncology section chief, and an investigator for PATHFINDER 2 at Sutter’s Palo Alto Medical Foundation Research Institute and co-author of the abstracts presented at ESMO.
Expanding Research into Everyday Care
New findings from PATHFINDER 2 illustrate critical progress made in shaping the future of how cancer is detected.

Dr. Amanda Wheeler
“The results presented at ESMO mark an important turning point in cancer detection and highlight Sutter’s role as a trusted research partner, contributing not just study participants, but also leadership and expertise to help translate innovation into patient care,” says Dr. Amanda Wheeler, chair of Sutter’s Advanced Cancer Service Line.
To learn more and to see if you qualify to join the next phase of this research in the REACH Study at Sutter, please contact clinicalresearch@sutterhealth.org.