A technology has been developed to detect cancer more accurately at an early stage through blood tests. This was made possible by changing the test target to a biomolecule that can easily be found in cancer cells. If commercialized, it is expected that cancer will be detected earlier, leading to improved treatment outcomes.
Researchers at the University of Chicago announced on the 8th that they have developed a liquid biopsy technology that can detect colon cancer at an early stage using ribonucleic acid (RNA) instead of deoxyribonucleic acid (DNA). The results of this study were published in the international journal “Nature Biotechnology”.
Cancer diagnosis has primarily relied on biopsy methods that involve directly removing tissue. Tissue samples can be difficult for patients and time-consuming. As an alternative, a liquid biopsy that searches for traces of cancer cells in the blood has been developed. This method diagnoses cancer by finding mutations or chemical modifications in DNA fragments released when cancer cells die.
Liquid biopsy does not inconvenience patients, but early diagnosis is challenging. In the very early stages of cancer, when cancer cells are just beginning to grow, there are almost no DNA fragments in the blood. The researchers at the University of Chicago focused on RNA to solve this problem.
RNA plays a role as a kind of blueprint in protein synthesis. Genetic information from DNA is copied into RNA only for the necessary parts and used for the synthesis of specific proteins. The presence of RNA also indicates that the cell is actively functioning.
Instead of merely measuring the quantity of RNA, the research team chose to analyze the ratio of chemical modifications that occur to RNA. RNA modifications are chemical changes that regulate the functions of RNA, and the research team previously confirmed in plant studies that the level of biological activity increases with higher RNA modifications.
The researchers stated that the ratio of RNA modifications remains consistent regardless of the amount tested, making it a highly stable diagnostic marker. For example, if a specific RNA has a modification of 30%, that ratio remains unchanged whether they measure 100 or 1,000 RNAs.
The research team analyzed blood samples from colon cancer patients to identify the modification patterns of RNA derived from human cells, and also analyzed RNA from gut microbiota. Gut microbiota are symbiotic bacteria living in the intestines and respond sensitively to the health status of the human body.
When cancer develops, the inflammatory response alters the gut environment, leading to changes in the gut microbiome as well. This change can also be confirmed through RNA modification patterns. Particularly, gut microbiota have shorter life cycles than human cells, meaning they decompose more frequently, rapidly releasing RNA into the bloodstream. This is a crucial clue for early detection of changes caused by cancer.
Experimental results showed that liquid biopsy based on RNA modification exhibited approximately 95% diagnostic accuracy across all stages of cancer progression. This accuracy was maintained even in early stages of cancer. Commercial tests measuring DNA and RNA content in credit entries show about 90% accuracy in advanced cancer stages, but drop below 50% in early cancer.
Professor Chuan He of the University of Chicago said, “The use of the RNA modification ratio as a biomarker for cancer diagnosis is a first, and it is more reliable than simply measuring the quantity of RNA,” adding that “it is unprecedented to detect early cancer so accurately.”
References
Nature Biotechnology (2025), DOI: https://doi.org/10.1038/s41587-025-02731-8