New cause of stomach cancer development found

An international group of researchers from China and the USA has made an important discovery in the field of oncology, identifying a previously unknown external factor that can cause somatic mutations in the gastric mucosa, which subsequently lead to cancer development. The results of this significant study were published in the scientific journal Nature.

Until now, the medical community has recognized only a few main risk factors for stomach cancer: excess body weight, tobacco smoking, and infection with the bacterium Helicobacter pylori. However, clinical practice shows that this oncological disease is often diagnosed in people who lead a healthy lifestyle and have no harmful habits.

Seeking to solve the mystery of stomach cancer occurrence in such patients, scientists conducted large-scale genomic sequencing of 238 samples of normal gastric tissue obtained from 30 volunteers from the UK, USA, and Hong Kong. Among the study participants, 18 people were diagnosed with stomach cancer. To improve the accuracy of identifying genetic mutations associated with the disease, researchers applied advanced laser imaging technology.

Analysis of the obtained data brought unexpected results. Contrary to assumptions that constant exposure to the aggressive acidic environment of the stomach should accelerate mutation processes, the study showed that mutations in normal stomach tissues occur at the same frequency as in most other cells of the body. However, in patients diagnosed with stomach cancer, characteristic changes were found in the cells, indicating the initial stage of the tumor process. In malignant tissues, the number of such mutations significantly increased.

A particularly intriguing discovery was the detection of three copies of certain chromosomes - 13, 18, and 20 - in some cells of the gastric mucosa. This phenomenon, known in genetics as trisomy, was identified only in some study participants. This observation allowed scientists to hypothesize about the existence of a previously unknown mutagen, the exposure to which is associated with the development of stomach cancer.

In addition, the study showed that by the age of 60, potentially dangerous mutations form in almost 10% of the cells of the gastric mucosa. A particularly high risk of their occurrence is observed in people suffering from chronic inflammatory processes in the stomach.