An investigational exosome-based liquid biopsy accurately detected 97% of stage I to II pancreatic cancers when combined with the biomarker CA 19-9, according to findings presented by Xu et al at the American Association for Cancer Research (AACR) Annual Meeting 2024. Early detection of pancreatic cancer is often challenging because of several factors: the nonspecific symptoms of the disease, the pancreas’ inability to be palpated during physical examination, and the unreliability of existing biomarkers such as CA 19-9 when used alone. Researchers developed an exosome-based liquid biopsy approach that analyzed exosomes shed by cancerous and healthy cells into the blood to determine whether the test could detect early-stage pancreatic cancer. The researchers identified eight microRNAs that were uniquely found in exosomes shed from these tumors. They combined these with five cell-free DNA markers found in the blood of patients with pancreatic cancer to establish a signature associated with the disease. The researchers previously tested the performance of the liquid biopsy signature in 95 patients, reporting a 98% pancreatic cancer detection rate. In the new study, they sought to evaluate the liquid biopsy in a group of 523 patients with pancreatic cancer and 461 healthy donors from Japan, the United States, South Korea, and China. After training the liquid biopsy signature on the Japanese cohort, they found that the test detected 93%, 91%, and 88% of the pancreatic cancers in the U.S., South Korean, and Chinese cohorts, respectively. Further, when combined with CA 19-9, the liquid biopsy accurately detected 97% of stage I and stage II pancreatic cancers in the U.S. cohort. Although further research may be needed before the test can be deployed in the general population, the researchers concluded that it may benefit high-risk patients such as those with chronic pancreatitis, new-onset diabetes, or a family history of pancreatic cancer.