Scientists in China have developed a new blood test that can find many types of cancer early, with impressive accuracy. This test, created by researchers from Geneseeq and several major hospitals, checks for tiny bits of DNA that are released into the bloodstream by cancer cells.
These pieces of DNA, known as cell-free DNA or cfDNA, float freely in the blood and can give clues about the presence of cancer—even before symptoms appear.
Detecting cancer early can save lives, but it is still a big challenge in medicine. Many types of cancer do not have regular screening tests, and even for those that do, people are often diagnosed too late. Current methods like imaging or tissue biopsies can miss early-stage cancers or are too invasive to be used regularly for every person.
That’s why the new blood test is so promising. It is based on analyzing patterns in cfDNA using a method called whole-genome sequencing. Instead of looking for one specific gene or mutation, the test looks at a wide range of DNA characteristics, including the size of the DNA fragments, their structure, and even chemical changes on the DNA that may suggest cancer.
Then, using computer programs powered by machine learning, the test not only checks if someone likely has cancer but also predicts where in the body the cancer started.
To develop and test this approach, the scientists used blood samples from over 3,000 people with cancer and more than 3,000 people without cancer. They trained the computer model to spot differences in the DNA of these two groups.
Then, to make sure the test really worked, they tested it on a new group of people whose diagnosis was unknown to the researchers doing the analysis. This way, the results would be more reliable.
In one large group of over 1,400 people, the test found cancer with an accuracy of 87.4%. That means it correctly detected nearly 9 out of 10 cases. It was also very good at avoiding false alarms—97.8% of people without cancer were correctly told they didn’t have it.
For certain cancers, such as liver and bile duct cancer, the test found 100% of cases. It also performed very well with lung, ovarian, and colorectal cancers. Even for difficult-to-detect cancers like pancreatic cancer, the test picked up more than three-quarters of the cases.
Importantly, the test could also tell where the cancer was likely located in the body. In more than 8 out of 10 cases, it correctly predicted the cancer’s origin. This helps doctors act faster and more accurately when deciding on treatment or follow-up tests.
The researchers also tested the blood test on over 3,700 healthy people to see how well it would work in real life. Within a year, 43 of those people were diagnosed with cancer.
The test correctly flagged more than half of them as having cancer, and it was still very accurate in saying who didn’t have cancer. In this group, nearly half the cancers that the test found were missed by regular screening methods like imaging or physical exams.
This new study shows that a simple blood test could become a powerful tool for finding cancer early—especially types of cancer that are usually discovered too late. Being able to tell where the cancer might be located makes the test even more useful for doctors.
However, the test is not perfect yet. In the group of healthy people, it correctly found just over half of the real cases, and its ability to guess the cancer’s origin was slightly lower than in the first group. The positive predictive value (how often a “positive” result really means cancer) was only 25%, meaning follow-up tests would still be necessary to confirm a diagnosis.
Still, the results are very encouraging. The scientists say their test could make a big difference in the future of cancer care. It could help doctors find cancer earlier and start treatment sooner, especially for cancers that currently don’t have good screening methods. With more research and testing, this blood test could one day be used regularly to help save lives.
If you care about cancer, please read studies that low-carb diet could increase overall cancer risk, and new way to increase the longevity of cancer survivors.
For more health information, please see recent studies about how to fight cancer with these anti-cancer superfoods, and results showing daily vitamin D3 supplementation may reduce cancer death risk.
The study is published in Nature Medicine.
Copyright © 2025 Knowridge Science Report. All rights reserved.
