FRIDAY, Sept. 25, 2026 (HealthDay News) -- A blood-based multicancer early detection (MCED) test that predicts cancer signal origin (CSO) has a positive predictive value of 60.3 percent for participants aged 50 years or older without clinical suspicion of cancer, with specificity of 99.64 percent, according to a study published online Sept. 22 in Nature Medicine.
Nima Nabavizadeh, M.D., from the Oregon Health & Science University in Portland, and colleagues expanded clinical evidence for the MCED test in the prospective interventional PATHFINDER 2 study, which examined coprimary end points of MCED performance metrics and safety in participants aged 50 years or older without clinical suspicion of cancer. A total of 35,878 participants were enrolled between December 2021 and July 2024.
The researchers found that the cancer detection rate was 0.54 percent among 32,007 performance-analyzable participants, while the positive predictive value and negative predictive value were 60.3 and 99.2 percent, respectively; specificity was 99.64 percent. Episode sensitivity was 39.3 and 69.8 percent for all cancers and in the prespecified 12-cancer subgroup, respectively. The positive likelihood ratio was 108.9 and negative likelihood ratio was 0.61; to detect one cancer, the number needed to screen was 185. The prediction accuracy was 91.3 percent for CSO. Overall, 0.6 percent of 35,335 safety-analyzable participants had invasive procedures after a positive MCED test, 90.5 percent of which were nonsurgical.
"We screen for just five cancers, yet the ones we can't screen for cause up to 70 percent of cancer deaths in this country; that's the gap this blood test helps close," Nabavizadeh said in a statement.
Several authors disclosed ties to pharmaceutical and biotechnology companies, including GRAIL, which is developing this MCED test and funded the study.
