Kim, 41 this year, holds the key post of head of planning at a company. Kim had experienced a symptom since last year in which blood was mixed in the credit entry. Thinking it was just simple hemorrhoids, Kim did not take it seriously and kept putting off going to the hospital, thinking a health check later would be fine. But at the early-year health check, after undergoing a colonoscopy, Kim was diagnosed with stage 3 colon cancer.
Colon cancer is one of the most common cancers in Korea, following lung and stomach cancer. It is the third most common cause of cancer deaths after lung and liver cancer. In Korea, about 35,000 new cases of colon cancer are diagnosed each year. But compared with other cancers, colon cancer has a relatively good prognosis, and its risk factors are well known, making prevention and treatment easier. If found early, the five-year survival rate exceeds 90%. If the stage is low, a complete cure is possible with surgery, and chemotherapy is not needed.
However, if detection is delayed and the lesion invades the bowel wall and involves the lymph nodes, complex treatment becomes necessary. Still, even when there are metastases to the liver or lungs, if the metastatic foci (new tumors formed when cancer cells move from where they first arose to settle in other tissues or organs) are limited, long-term survival can be expected by surgically removing them or combining radiofrequency therapy.
The biggest characteristic of colon cancer is that it often remains for a long time as an adenomatous polyp (a benign tumor in the intestinal mucosa that can develop into cancer) before progressing to cancer. It usually takes several years to more than 10 years to progress from normal mucosa to an adenomatous polyp and then to cancer. Therefore, if an adenoma, a precancerous lesion, is found and removed by colonoscopy during this period, cancer can be avoided entirely.
In Korea, fecal occult blood testing (a screening test that detects trace amounts of blood in the credit entry to find abnormal bleeding in the digestive tract such as colon cancer, polyps, and hemorrhoids) is offered to adults 50 and older, and those with positive results are advised to undergo colonoscopy.
The problem is that colon cancer is increasingly occurring among younger people. Among young people in Korea, the incidence of colon cancer is 12.9 per 100,000, one of the highest in the world. According to the Health Insurance Review & Assessment Service, the number of colon cancer patients in their 20s and 30s in Korea jumped by a striking 34.3% over the four years from 2017 to 2021. Of course, patients in their 50s and older still account for the majority of colon cancer cases. But in terms of growth rate, it is much steeper among younger people. In fact, among younger people, colon cancer is often found late, as in Kim's case. Those under 50 are not covered by the national screening program, and even when symptoms such as abdominal pain or blood in the stool appear, many patients mistake them for irritable bowel syndrome or hemorrhoids.
Population aging, obesity, increased consumption of red meat, lack of fiber intake, insufficient physical activity, drinking, and smoking are cited as reasons colon cancer is rising quickly among younger people. In particular, colon cancer has a strong genetic tendency, so incidence rises sharply when there is a family history. It is important to have colonoscopies a bit earlier and a bit more often. With persistent blood in the stool, changes in bowel habits, unexplained anemia, or weight loss, a person should see a doctor regardless of age.