Liver cancer is the second most common cancer death rate in Korea. “I thought I could just cut down on drinking.”

A, who rarely drinks alcohol because of his family history, is weak. Then one day, through a health check-up, he underwent a blood test and an abdominal ultrasound, and the doctor found that he had liver cancer. As a result of the detailed examination, A was diagnosed with liver cancer. It was unacceptable news for Mr. A, who did not drink alcohol.

Liver cancer is a target of caution among ‘drinkers’. This is because alcohol is the main cause of liver cancer by damaging liver health. However, besides alcohol, there are many factors that promote liver cancer, so it is necessary to pay attention to health management. In particular, liver cancer is known as a cancer with a poor prognosis. As of 2019, liver cancer was the second most common cause of death among cancers in Korea. The Korea Liver Foundation and the Korean Liver Society designate October 20 every year as ‘Liver Day’ to raise awareness about liver disease and encourage diagnosis and treatment.

One of the major causes of liver cancer is free radicals. According to the Gwangju Institute of Science and Technology (GIST), the excessive accumulation of free radicals in the body is mainly involved in the development of malignant liver cancer. Oxygen free radical refers to ‘harmful oxygen’ in which oxygen that enters the body during respiration is transformed by various oxidation processes.

Free radicals produced excessively by light pollution, chemicals, ultraviolet rays, and stress attack living tissues and damage cells. Accordingly, the research team led by Professor Seong-gyu Park of the Department of Life Sciences at GIST and the team of Professor Gu-heung Jeong of Seoul National University established a hypothesis that free radicals have a major effect on the development of liver cancer.

As a result, it was found that the protein PDIA3 (disulfide bond isomerase protein that regulates oxidation, reduction, and isomerization of proteins) oxidatively modified by free radicals increases DKC1, which induces malignancy, and consequently promotes the development of malignant liver cancer. did.

Free radicals increase with stress and also under the influence of tobacco. Tobacco also contains hydrogen peroxide, which is a type of active oxygen, which generates a lot of free radicals in the body. Excessive exercise and overeating are also considered causes of increased free radical generation.

Nonalcoholic fatty liver, in which fat accumulates in the liver due to a high-fat diet and insufficient exercise, is also classified as a potential liver cancer factor. Recently, the prevalence of nonalcoholic fatty liver among men in Korea is on the rise.

A team led by Professor Hyesoon Park (Department of Family Medicine) and Seoyoung Kang (International Medical Center) at Asan Medical Center in Seoul investigated the prevalence of obesity, abdominal obesity, and non-alcoholic fatty acids in 40,000 adults aged 19 and over who participated in the National Health and Nutrition Survey from 1998 to 2017. analyzed. The subjects were those who had never had liver disease such as hepatitis or cirrhosis in the past and who rarely drink alcohol with an alcohol intake of 30 g or less at a time.

As a result, the prevalence of nonalcoholic fatty liver in Korean men increased by 11 percentage points from 19.7% in 1998 to 30.7% in 2017. During the same period, the average body mass index (BMI) increased from 22.9 to 24.5, and the average waist circumference also increased by more than 4 cm from 81.9 cm to 86.1 cm. A BMI of 25 or more is considered obese, and a waist circumference of 90 cm or more is considered abdominal obesity.

Nonalcoholic fatty liver disease is closely related to lifestyle. In fact, the proportion of men who consume more than 30% of their daily energy intake from fat has doubled compared to 19 years ago, and the proportion of men who lack physical activity has also increased significantly.

If non-alcoholic fatty liver is left unattended, it can progress to cirrhosis and liver cancer, which in severe cases requires liver transplantation. Professor Park Hye-soon said, “Non-alcoholic fatty liver is often mild with only fat accumulation and no liver damage, but if left untreated, it can develop into hepatitis, which damages the liver cells, cirrhosis, which hardens the liver, and liver cancer, a malignant tumor.”

Studies on improving fatty liver are also in progress. The Korea Advanced Institute of Science and Technology (KAIST) and Seoul National University Bundang Hospital investigated the effect of suppressing the neurotransmitter ‘serotonin’ signal to improve and inhibit fatty liver disease along with diabetes.

Unlike its role in the brain, serotonin regulates various energy metabolism in peripheral tissues in the context of obesity and diabetes. The joint research team found that inhibiting the signaling of serotonin 2B receptors in adipocytes reduces the inflammatory response in adipose tissue. In addition, it confirmed the effect of improving overall metabolic indicators such as suppression of fatty liver and increase in systemic insulin sensitivity.