Stomach cancer is frequently detected through screening rather than symptoms. Because early signs are hard to distinguish from common digestive complaints, doctors say the surest safeguard for people aged 40 and over is a regular endoscopy, regardless of whether symptoms are present.
Stomach cancer ranked fifth among all cancers by number of new patients, according to data from the Ministry of Health and Welfare and the Korea Central Cancer Registry released on the 24th. A survey by the International Agency for Research on Cancer, part of the World Health Organization, found that 27 out of every 100,000 Koreans were newly diagnosed with the disease. Statistics Korea's 2021 cause-of-death data put the stomach cancer mortality rate at 14.1 per 100,000 people.
Stomach cancer refers broadly to malignant tumors in the stomach, and most cases are gastric adenocarcinoma, which develops in the glandular cells of the stomach lining. Cancer that begins in the lining burrows deeper into the stomach wall over time. If it advances further, it can spread to nearby lymph nodes as well as other organs including the liver, lungs and peritoneum.
One of the main causes is infection with Helicobacter pylori. The bacterium triggers chronic inflammation in the stomach lining, which can lead to atrophic gastritis and intestinal metaplasia. Diets heavy in salty or charred foods and processed products also raise the risk. Smoking is known to increase the risk of stomach cancer roughly 2.5 times. A family history of the disease and previous stomach surgery are additional risk factors.
Early-stage stomach cancer appears as common complaints such as heartburn, bloating and indigestion, or produces almost no symptoms at all. Weight loss, loss of appetite, difficulty swallowing, repeated vomiting and black stools often indicate the disease has progressed considerably. Persistence matters more than severity. If similar discomfort keeps recurring, it is best to identify the cause rather than dismiss it as a simple digestive problem.
Endoscopy is used as the most accurate test for identifying stomach cancer. If an abnormal area is found, a biopsy confirms the diagnosis, and imaging such as a CT scan is used to assess how far the disease has advanced and determine the course of treatment.
Prevention starts with cutting back on salty and spicy foods, eating plenty of vegetables and fruit, quitting smoking and limiting alcohol. If a Helicobacter pylori infection is confirmed, patients should consult a specialist to decide whether to undergo treatment.
Cho Joon-hyung, a professor of gastroenterology at Soonchunhyang University Seoul Hospital, stressed that stomach cancer can be treated successfully when caught early, but that the later it is found, the more complicated treatment becomes and the heavier the burden on patients. Cho added that when stomach discomfort persists, patients should not simply assume indigestion but should confirm the cause through proper testing.
Meanwhile, the national cancer screening program provides an endoscopy every two years to men and women aged 40 and over. In 2026, those born in even-numbered years are eligible. Eligible individuals can book an appointment in advance and visit a designated national cancer screening facility with photo identification, and screening is available at any facility nationwide regardless of where they live. Out-of-pocket costs are either waived or set at 10%, depending on the category of the recipient.