Doctors may soon be able to better decide how to treat early-stage stomach cancer using a new tool that combines a blood test and imaging.
Researchers from the Institute of Science Tokyo have developed a new diagnostic model that helps predict whether cancer has spread to nearby lymph nodes. This could help many patients avoid invasive surgeries they may not actually need.
Early-stage gastric cancer, also called stomach cancer, is often found when the disease is still limited to the inner lining of the stomach. In these cases, the outlook is very good. More than 90% of people survive five years or more.
If doctors believe the cancer has not spread, they often recommend a less invasive treatment called endoscopic resection. This procedure removes the cancer through a tube inserted into the stomach, allowing the patient to keep their stomach and recover more quickly.
However, if doctors think the cancer may have spread to the lymph nodes, they usually recommend a much more serious surgery called radical gastrectomy. This surgery removes part or all of the stomach along with surrounding lymph nodes. It is more invasive, with longer recovery time and more risks.
The problem is that it’s very hard to know for sure whether the cancer has spread before surgery. CT scans are commonly used, but they often miss small signs of cancer in the lymph nodes. In fact, CT scans can fail to detect spread in up to 50% of cases. Because of this uncertainty, doctors often choose the more aggressive treatment just in case.
As a result, many patients may undergo major surgery when it isn’t really necessary. Less than 20% of early-stage stomach cancer patients actually have cancer that spreads to the lymph nodes, meaning the majority are likely being overtreated.
To solve this issue, researchers led by Assistant Professor Keisuke Okuno developed a new test based on what’s called a liquid biopsy. Instead of taking a tissue sample through surgery, they used a blood sample to look for markers linked to cancer spread.
They focused on DNA methylation, a chemical change in DNA that can affect how genes work. These changes often appear when cancer is present.
The research team found six new DNA methylation markers by studying both tumor samples and blood samples from patients. They then combined these results with CT scan findings to create a model that predicts the risk of cancer spread more accurately.
The new model was tested using data from previous patients. It showed very good results. The tool was able to identify which patients were truly at low risk of cancer spread. Importantly, it did not miss any patients who actually had cancer in their lymph nodes. With this model, about 44% of patients could safely avoid surgery, according to the study.
“Our model allows nearly half of early-stage stomach cancer patients to skip major surgery without missing any serious cases,” said Professor Okuno. “This could become a noninvasive and reliable way to plan treatment for patients.”
The research was published in the United European Gastroenterology Journal on October 17, 2025. The scientists believe this new approach could become an important part of personalized medicine, where treatments are tailored to each patient’s specific condition.
More studies will be needed before this test becomes widely used in hospitals. Large trials involving multiple medical centers are planned. But the researchers are hopeful. With better tools to predict how cancer behaves, doctors can make more informed decisions. Patients will benefit from fewer unnecessary treatments and a better quality of life.
If you care about cancer, please read studies that artificial sweeteners are linked to higher cancer risk, and how drinking milk affects risks of heart disease and cancer.
For more health information, please see recent studies about the best time to take vitamins to prevent heart disease, and results showing vitamin D supplements strongly reduces cancer death.
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