>>10429943
Non-invasive early detection of cancer four years before conventional diagnosis using a blood test
https://www.nature.com/articles/s41467-020-17316-z
Abstract
Early detection has the potential to reduce cancer mortality, but an effective screening test must demonstrate asymptomatic cancer detection years before conventional diagnosis in a longitudinal study. In the Taizhou Longitudinal Study (TZL), 123,115 healthy subjects provided plasma samples for long-term storage and were then monitored for cancer occurrence. Here we report the preliminary results of PanSeer, a noninvasive blood test based on circulating tumor DNA methylation, on TZL plasma samples from 605 asymptomatic individuals, 191 of whom were later diagnosed with stomach, esophageal, colorectal, lung or liver cancer within four years of blood draw. We also assay plasma samples from an additional 223 cancer patients, plus 200 primary tumor and normal tissues. We show that PanSeer detects five common types of cancer in 88% (95% CI: 80–93%) of post-diagnosis patients with a specificity of 96% (95% CI: 93–98%), We also demonstrate that PanSeer detects cancer in 95% (95% CI: 89–98%) of asymptomatic individuals who were later diagnosed, though future longitudinal studies are required to confirm this result. These results demonstrate that cancer can be non-invasively detected up to four years before current standard of care.
Introduction
Late stage cancers often lack an effective treatment option1,2. Survival rates increase significantly when cancer is identified at early stages, as the tumor can be surgically removed or treated with milder drug regimens3; average 5-year survival at early stage is 91%, while average 5-year survival at late stage is 26%4. Detection of tumors at the earliest possible stage is therefore of paramount importance for cancer treatment. Currently, a limited number of screening tests exist for a few cancer types, including colonoscopy5, prostate specific antigen6, mammography7, and cervical cytology8. However, the efficacy of some tests has been questioned9, and many patients do not follow medical guidelines for screening10. Most cancer types currently lack an effective non-invasive early screening option11. Importantly, a formal demonstration of early detection requires collecting samples years before conventional cancer diagnosis, which is only feasible with longitudinal tracking of a large number of healthy individuals and identifying the very small fraction who develop cancer over time (at the incidence rate of cancer in the general population).