A new research initiative led by the Oregon Health & Science University Knight Cancer Institute, named PATHFINDER 2, has revealed that a single blood test, capable of screening for over 50 types of cancer, substantially improves early detection when combined with traditional screening protocols. This innovative approach identifies malignancies that might otherwise progress to advanced stages unnoticed. The study, published in Nature Medicine, highlights the effectiveness of GRAIL's Galleri test, which employs a sophisticated machine-learning algorithm to distinguish between healthy and cancerous cell-free DNA.
These findings are particularly significant as they coincide with the Food and Drug Administration's (FDA) advisory committee review for potential approval of the Galleri test. Dr. Nima Nabavizadeh, the lead author and director of early detection clinical research at OHSU Knight Cancer Institute, emphasized the test's potential to bridge critical gaps in current cancer screening. He noted that existing screening methods cover only a fraction of cancers, whereas this blood test can detect many others while they are still localized and asymptomatic, thereby increasing the chances of successful treatment. This test is envisioned as a powerful supplement to, rather than a replacement for, standard screening procedures, aiming to significantly boost early cancer diagnoses.
Enhanced Early Cancer Detection with Novel Blood Test
The PATHFINDER 2 trial, which forms the basis for GRAIL's FDA application, enrolled a vast cohort of 35,878 individuals aged 50 and above across North America, establishing it as the most extensive interventional multi-cancer early detection study in the region. OHSU played a pivotal role, enrolling approximately 6,100 participants. The study's results demonstrated a remarkable 6.5-fold increase in cancer detection rates when the Galleri test was added to existing screening recommendations for breast, colorectal, cervical, and lung cancers. Notably, nearly half of the newly identified cancers were diagnosed at stages 1 or 2, and almost three-quarters were found by stage 3, phases where curative interventions are often more feasible. A significant 70% of these detected cancers are currently without national screening guidelines, underscoring the test's potential to address a major unmet need in oncology. This technology could revolutionize screening for aggressive cancers like pancreatic, ovarian, liver, and bile duct cancers, which are typically diagnosed only after symptoms manifest.
The clinical impact of the Galleri test was profoundly illustrated by the case of Franklin Weingarten, a study participant whose early-stage cholangiocarcinoma, a rare and aggressive bile duct cancer, was detected through the blood test. Without this early diagnosis, his cancer would likely have been found at an incurable stage. Dr. Nabavizadeh highlighted the immense benefit of such early detection, allowing for timely surgical intervention and significantly improving patient outcomes. This case exemplifies how the test can transform the trajectory of diseases that are usually diagnosed too late. The study also reported an impressive specificity of 99.64% for the Galleri test, resulting in a minimal false-positive rate of just 0.36%. Furthermore, for positive results, the test accurately predicted the cancer's origin with 91.3% accuracy, streamlining subsequent diagnostic procedures and reducing unnecessary invasive tests. Only 0.6% of participants with positive results underwent invasive procedures, most of which were non-surgical, demonstrating the test's high reliability and patient-friendly nature.
Advancing Cancer Screening and Future Directions
The success of the PATHFINDER 2 trial has cemented the OHSU Knight Cancer Institute's position as a leader in early cancer detection. Dr. Nabavizadeh underscored the critical role of the Knight Early Detection Clinical Research Team and its collaborators across Oregon in achieving this milestone. The extensive network of community partners, including the Oregon Rural Practice-based Research Network, St. Charles Health System, Salem Hospital, and Bay Area Hospital, facilitated broad participation and robust data collection. This collaborative effort has equipped the OHSU team with unparalleled expertise in deploying multi-cancer early detection tests, interpreting results, and guiding patients through diagnostic pathways, effectively shaping the future of cancer screening practices and health system integration.
OHSU is continuing its pioneering work with two new studies: REACH and INFORM. The REACH study is currently enrolling Medicare beneficiaries to evaluate annual multi-cancer early detection testing, with expanded access through community sites across Oregon. The INFORM study, a joint venture with Dana-Farber Cancer Institute, will focus on individuals with inherited cancer risks, strong family histories, or genetic predispositions, offering at-home testing via telehealth, mobile phlebotomy, and community laboratory partnerships. These initiatives are poised to further advance multi-cancer early detection technology. Dr. Nabavizadeh emphasized that while the promise of detecting numerous cancers with a single blood test is compelling, rigorous clinical validation, like that provided by PATHFINDER 2 and ongoing studies in the United Kingdom, is essential for its widespread adoption. Patients like Bart Dawkins, whose liver cancer was detected early by Galleri, attest to the life-saving potential of this innovative testing, underscoring the urgent need for its broader implementation in preventative healthcare.