Blood test would detect 5 cancers years before symptoms
An international research team reports that they have developed a non-invasive blood test that can detect five cancers four years before symptoms appear.
Detecting cancer long before it induces symptoms and is therefore already well developed is the current challenge for cancer doctors and researchers.
In a study published July 21 in the journal Nature Communications, an international research team appears to be close to achieving this. He reports that he has developed a non-invasive blood test capable of detecting five common cancers, on average four years before the disease can be diagnosed with current methods. In detail, this blood test detects cancers of the stomach, esophagus, lungs, liver, and colorectal cancer.
To develop this test, the team took blood plasma samples from more than 120,000 people between 2007 and 2017. Each participant took blood samples regularly for 10 years, and underwent regular examinations with doctors. When an individual was diagnosed with cancer, the researchers had access to blood samples taken one to four years before the onset of symptoms. This allowed the team to examine and compare blood samples from "healthy" and diseased individuals, and to see the differences.
In total, the team had access to blood samples from 605 asymptomatic individuals, of whom 191 were subsequently diagnosed with stomach, liver, lung, esophagus, and colorectal cancer. The team also had access to blood tests from 223 cancer patients and 200 samples from primary tumors and normal tissue.
Using all of this biological data, the researchers developed the test called PanSeer, which successfully detected future cancer in 91% of the samples from individuals who were initially asymptomatic but diagnosed with cancer and four years after the sample. Additionally, the test accurately detected cancer in 88% of the samples from 113 patients who had already been diagnosed at the time of collection, and recognized the samples as cancer-free 95% of the time.
If the study has limitations due to the relatively small number of participants, the risk of sample contamination, or the fact that the type of cancer remains unknown, the researchers believe these initial results are encouraging and validate their method, based on a characteristic molecular form of tumor DNA circulating in the blood.
More research will be needed to refine this first test, which could be a formidable tool for early detection of cancers. The latter is crucial since the survival of cancer patients increases considerably when the disease is identified and treated as soon as possible.