A non-invasive blood test, which could be used as a potential tool for the early detection of five common types of cancer up to four years before conventional diagnosis, is reported in a China study.
The survival of cancer patients significantly increases when the disease is identified at early stages, as the tumour can be surgically removed or treated with appropriate drugs. However, only a limited number of screening tests exist for a few cancer types.
In their study, Kun Zhang and colleagues at the State Key Laboratory of Genetic Engineering and Collaborative Innovation Centre for Genetics and Development, School of Life Sciences, Fudan University, in Shanghai describe a blood-based cancer screening test, called PanSeer, which examines cancer-specific methylation signatures in the blood.
The authors perform an analysis on plasma samples obtained from 605 asymptomatic individuals, 191 of whom were later diagnosed with cancer. They also profile plasma samples from an additional 223 diagnosed cancer patients as well as 200 primary tumour and normal tissue samples. The authors demonstrate that their test can potentially detect with high specificity five common types of cancer (stomach, oesophageal, colorectal, lung or liver cancer) in post-diagnosis patients, as well as in asymptomatic individuals up to four years before conventional diagnosis.
The authors emphasise that the PanSeer assay is unlikely to be predicting patients who will later go on to develop cancer. Instead, it is most likely identifying patients who already have cancerous growths, but remain asymptomatic to current detection methods. They conclude that further large-scale longitudinal studies are needed to confirm the potential of the test for the early detection of cancer in pre-diagnosis individuals.
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.
Xingdong Chen, Jeffrey Gole, Athurva Gore, Qiye He, Ming Lu, Jun Min, Ziyu Yuan, Xiaorong Yang, Yanfeng Jiang, Tiejun Zhang, Chen Suo, Xiaojie Li, Lei Cheng, Zhenhua Zhang, Hongyu Niu, Zhe Li, Zhen Xie, Han Shi, Xiang Zhang, Min Fan, Xiaofeng Wang, Yajun Yang, Justin Dang, Catie McConnell, Juan Zhang, Jiucun Wang, Shunzhang Yu, Weimin Ye, Yuan Gao, Kun Zhang, Rui Liu,Li Jin