Multicancer Early Detection Blood Test Performance in Cancer Survivors From the PATHFINDER Study

Cancer survivors are at risk for recurrence and second primaries, yet often lack clear guidance for long-term surveillance.

We assessed the performance of a blood-based multicancer early detection (MCED) test in 1,609 survivors who participated in PATHFINDER, a prospective study of adults without current suspicion of cancer.

Previous cancers included breast (47%), melanoma (10%), prostate (9%), colorectal (4%), and lymphoma (4%). Average time since diagnosis was 11.2 years, and a cancer signal was detected in 1.2% (20/1,609). Ten new cancer diagnoses occurred: 5 second primaries (stage I uterine, stage II sarcoma, stage III ovarian, stage IV lymphoma, and stage IV colorectal) 8-15 years after original diagnosis and five recurrences (breast cancer) 4-11 years after original diagnosis. Test performance metrics were similar in those with and without previous cancer history.

These findings highlight the potential of MCED tests to address a significant unmet need in long-term surveillance of survivors.