With this new technology, gastric cancer detection bid farewell to gastroscopy and barium meal
Gastroscope and barium meal are currently the two most commonly used methods for detecting gastric cancer.
Compared with these two methods, a major feature of the DNA methylation detection method is that it is non-invasive. It does not require "intubation" or "filming", and its biggest advantage is that it can complete multiple cancer types at once. Screening greatly improves the efficiency of screening.
Gastric cancer is not easily detected at an early stage, leading to a higher mortality rate.
Regular screening, early detection and early treatment are the best ideas for dealing with gastric cancer.
However, gastroscopy screening is a "suffering" physical examination item for many people, and the sensitivity of the currently used serum tumor markers (such as carcinoembryonic antigen) is very low. How to solve these problems?
"DNA methylation to detect cancer" may become a new solution.
Peking University Biomedical Frontier Innovation Center, Beijing Future Gene Diagnosis Advanced Innovation Center Tang Fuchou, Wenlu team and Peking University Third Hospital Department of General Surgery Fu Wei team cooperated through the detection of cancer methylation markers in plasma free DNA Sequencing analysis has realized the early non-invasive detection of gastric cancer and the non-invasive early differential detection of gastric cancer, colorectal cancer and liver cancer.
The results were recently published in the international academic journal "Clinical Chemistry".
The specificity of gastric cancer methylation markers is close to 100%
As one of the corresponding authors of the article, Associate Researcher Wen Lu introduced to a reporter from Science and Technology Daily that in 2015, based on the distribution characteristics of CpG short tandem sequences in the human genome, researchers developed a new technology MCTA-Seq that uses a single targeted primer to capture Nearly 9,000 CpG short tandem sequence methylation information, and use this technology for non-invasive detection of hepatocellular carcinoma; in 2019, researchers applied the technology to early non-invasive detection of colorectal cancer; in a paper published in 2021 , Researchers further applied the technology to early non-invasive detection of gastric cancer and non-invasive differential detection of three types of gastrointestinal cancers.
In this study, researchers identified a set of methylation markers that distinguish gastric cancer from normal gastric mucosa, and another set of methylation markers that distinguish gastric cancer, colorectal cancer, and liver cancer.
Using these markers, researchers have established a classifier to detect and distinguish the above three cancer types.
The sensitivity of this classifier to detect gastric cancer, colorectal cancer and liver cancer is 56%, 78%, and 85%, respectively. The accuracy of distinguishing the three cancer types is 94%, 80%, and 68%, and the specificity is close to 100%.
"However, starting from the current sample size and experimental results, this technology is still about 5 years away from clinical application." Wenlu explained, "Many colleagues around the world are exploring in this direction. Take the study as an example. At present, the detection results they get are about the same as ours. But our goal is to find the most suitable markers and use simpler methods and lower costs to get the same level of results."
The biggest advantage of DNA methylation detection methods is non-invasive
Gastroscope and barium meal are currently the two most commonly used methods for detecting gastric cancer.
The former requires the patient to receive anesthesia and insert a light guide tube into the patient's stomach; the latter requires the patient to take barium sulfate emulsion and receive X-ray irradiation.
Compared with these two methods, a major feature of the DNA methylation detection method is that it is non-invasive and does not require "intubation" or "filming".
However, the biggest advantage of the new method is that it can complete the screening of multiple cancers at one time, greatly improving the screening efficiency.
In future clinical applications, patients can be screened for possible cancers through DNA methylation methods, and then confirmed by specific diagnostic methods corresponding to the cancers.
"The prospect of using MCTA-Seq for noninvasive tumor early screening is very broad." Wen Lu commented, "Our study only covers 3 gastrointestinal cancers, but MCTA-Seq technology has the ability to screen and detect different cancers. The ability of methylation markers, the top ten cancers led by lung cancer, and even dozens of cancer types, may be covered in the future. In addition, DNA methylation detection methods can also be combined with other detection methods to increase Sensitivity and accuracy, reducing the false positive rate. These are the future development directions of technology."