Cancer often shows no clear symptoms in its early stages and is frequently detected only after it has progressed considerably. As the leading cause of death among Koreans, with a 36.9% chance of developing the disease for those who survive to the life expectancy of 83.5 years, recognizing subtle changes the body sends early on is important. Experts cite weight loss and severe fatigue as common signals of cancer.
"The most important common signals of cancer are weight loss and severe fatigue," said Choi Seok-jae, a professor of emergency medicine at Yeouido St. Mary's Hospital. "In the case of stomach cancer and colorectal cancer, black stool or bloody stool can appear, and in pancreatic cancer, jaundice and indigestion can occur."
Chronic fatigue, in particular, is a symptom that is easy to overlook. "Fatigue can be a signal that cancer is sending, but most people tend to ignore it, assuming it's just because they're busy," Choi stressed. "If fatigue persists, it suggests the possibility that a problem has arisen, so it requires attention."
Rising fat levels found in health checkups should also not be taken lightly. "You need to accept that a problem has arisen in your metabolic environment and change your eating habits," Choi advised. When blood triglyceride or cholesterol levels rise, fat accumulates in blood vessels, leading to arteriosclerosis, and over the long term, the risk of cardiovascular and cerebrovascular diseases such as myocardial infarction and stroke also increases.
The starting point of prevention is dietary habits. The International Agency for Research on Cancer (IARC) under the World Health Organization (WHO) analyzes that 30% of cancer deaths are attributable to smoking and 30% to dietary factors, with alcohol reported at around 5%. Choi also presented smoking cessation and abstinence from alcohol as top priorities, saying, "Cigarettes account for 30% of cancer causes, and alcohol accounts for 5%."
Consumption of ultra-processed foods must also be reduced. "Ultra-processed foods must be thoroughly excluded from the table," Choi said. "They damage the gut ecosystem and raise sugar levels, becoming a major cause of cancer and metabolic diseases." For red meat, boiling or steaming is recommended over grilling or charring.
According to the National Cancer Center, about 280,000 new cancer patients are diagnosed annually. As the patient population is expected to increase further due to population aging, removing risk factors from daily habits is cited as the most realistic countermeasure.
