An international team of researchers has developed a non-invasive blood test that can detect if a person has one of the five common types of cancer, four years before the condition can be diagnosed with current methods. The test detects cancer of the stomach, esophagus, colorectal, lung, and liver.
Called PanSeer, the test detected cancer in 91% of samples from individuals who had been asymptomatic when the samples were collected and were only diagnosed with cancer one to four years later. Additionally, the test accurately detected cancer in 88% of the samples from 113 patients who had already been diagnosed when the samples were collected. The test also recognized cancer-free samples 95% of the time. H.H
Additionally, the test accurately detected cancer in 88% of the samples from 113 patients who had already diagnosed five common cancers. The test also recognized cancer-free samples 95% of the time.
The study is unique in that the researchers had access to blood samples from asymptomatic patients who had not yet been diagnosed. This allowed the team to develop a test that can find cancer markers much earlier than conventional diagnostic methods. The samples were collected as part of a 10-year longitudinal study started in 2007 by Fudan University in China.
The ultimate goal would be to routinely perform blood tests like this during annual health checks. But the immediate approach is to assess the people most at risk, based on family history, age, or other known risk factors. “
Kun Zhang, one of the corresponding authors of the article and professor and chair of the Department of Bioengineering at the University of California, San Diego.
Early detection is important because the survival of cancer patients is significantly increased when the disease is identified in the early stages, since the tumor can be surgically removed or treated with the appropriate medications. However, there is only a limited number of early detection tests for some types of cancer.
Zhang and colleagues present their work in the July 21, 2020 issue of Nature’s Communications. The team includes researchers from Fudan University and Singlera Genomics, a startup based in San Diego and Shanghai that is working to commercialize evidence based on advances originally made in Zhang’s bioengineering lab at UC San School of Engineering. Diego Jacobs.
The researchers emphasize that the PanSeer trial is unlikely to predict which patients will later develop cancer. Instead, it is most likely to identify patients who already have cancerous growths, but who remain asymptomatic for current screening methods. The team concluded that more large-scale longitudinal studies are needed to confirm the potential of the test for early detection of cancer in pre-diagnosed individuals.
Longitudinal study of Taizhou
Blood samples in the Nature’s Communications The study was collected as part of the Taizhou Longitudinal Study, which collected plasma samples from more than 120,000 people between 2007 and 2017. Each individual gave blood samples over a 10-year period and underwent regular check-ups with doctors. In total, more than 1.6 million specimens have been collected and filed to date.
Once a person was diagnosed with cancer, the researchers had access to blood samples taken one to four years before these patients began to show symptoms.
The team was able to examine samples from healthy and sick individuals from the same cohort. The authors performed an analysis on plasma samples obtained from 605 asymptomatic individuals, of whom 191 were subsequently diagnosed with cancer. They also profile plasma samples from an additional 223 diagnosed cancer patients, as well as 200 samples from primary tumor and normal tissue.
Diagnostic method based on DNA methylation
Zhang and his laboratory have been developing cancer detection methods for more than a decade based on a biological process called DNA methylation analysis. The method detects a particular DNA signature called CpG methylation, which is the addition of methyl groups to multiple adjacent CG sequences in a DNA molecule. Each tissue in the body can be identified by its unique signature of methylation haplotypes. They did an early-stage proof-of-concept study that was published in a 2017 article in Genetics of nature.
Zhang co-founded Singlera Genomics, which licensed the technology he developed at UC San Diego. In the past few years, Singlera Genomics has been working to improve and eventually market cancer early detection tests, including the PanSeer test, which was used in the Nature’s Communications study. Zhang is now the company’s scientific advisor.
Zhang, Singlera Genomics, and additional collaborators have been working to make a formal demonstration that cancer can be detected in the blood before conventional diagnosis. July 2020 Nature’s Communications Publishing is the result of that effort.
Source:
University of California – San Diego
Journal reference:
Chen, X. et al. (2020) Early non-invasive detection of cancer four years before conventional diagnosis using a blood test. Communications from nature. doi.org/10.1038/s41467-020-17316-z.
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