Which Country Has the Most Stomach Cancer Cases? — 2026 Update

The available source material does not include country-by-country statistics on stomach cancer incidence or patient rankings, so we cannot answer "which country has the most stomach cancer patients." That said, Korea has a well-established national gastroscopy screening system and is a country where a large volume of stomach cancer diagnoses and surgeries take place, and treatment outcome statistics for Korea are available.

Key Takeaways

• Country-by-country rankings of stomach cancer incidence or patient numbers are not included in the available material, so we cannot tell you "which country has the most stomach cancer patients."
• That said, Korea is known as one of the countries with the most experience diagnosing and treating stomach cancer, and it operates a national gastroscopy screening program every two years starting at age 40.
• Korea's 5-year relative survival rate for stomach cancer is 78.6% (National Cancer Registry Statistics, 2019–2023, National Cancer Center Korea), compared with 39.8% in the United States (SEER, 2016–2022).
• Both figures are nationwide averages, not the results of any single hospital, and much of the gap reflects differences in early-detection rates rather than treatment technology alone.
• Survival rates are population averages and do not predict an individual's outcome; actual prognosis depends on stage, tumor type, age, and coexisting conditions.

Can We Identify the Country With the Most Stomach Cancer Cases?

• No. The knowledge notes available do not include country-by-country data on stomach cancer incidence or case-count rankings—only comparative 5-year relative survival rates by cancer type (post-treatment outcomes).
• Incidence and survival rate are different metrics and should not be confused. A higher incidence rate does not necessarily mean lower survival, and vice versa.
• However, the notes do describe Korea as one of the countries that diagnoses and performs surgery for stomach cancer most frequently in the world, so it can be introduced as a country with extensive experience in diagnosing and treating this disease.

Why Is There a Difference in Stomach Cancer Survival Between Korea and the US?

• The gap is driven not just by differences in treatment technology but significantly by how early the cancer is detected. Korea's 5-year relative survival rate for stomach cancer is 78.6% (National Cancer Registry Statistics, 2019–2023), while the US rate is 39.8% (SEER, 2016–2022).
• Because Korea runs a national gastroscopy screening program every two years from age 40, a relatively high proportion of cases are diagnosed as early-stage stomach cancer. Early-stage stomach cancer can often be treated with endoscopic submucosal dissection (ESD) alone, without removing the stomach.
• The two datasets cover different periods (2019–2023 vs. 2016–2022) and represent nationwide statistics rather than any single hospital's outcomes, so direct comparison should be made cautiously.

What Is the Typical Sequence for Diagnosing and Treating Stomach Cancer?

• Step 1, Gastroscopy and biopsy — confirms whether cancer is present and identifies the tumor type (intestinal or diffuse type, degree of differentiation).
• Step 2, CT and additional tests — assess how deeply the tumor has invaded the stomach wall, lymph node involvement, and spread to other organs. Endoscopic ultrasound may be added for early-stage cases.
• Step 3, Staging (TNM) — Stage 1 means the cancer remains in the shallow layers of the wall with no or minimal lymph node spread; stages 2–3 mean deeper wall invasion or lymph node involvement; stage 4 means spread to distant organs.
• Step 4, Treatment — early-stage stomach cancer is managed with endoscopic resection; operable cases undergo gastrectomy with lymph node dissection; advanced or metastatic cases are primarily treated with systemic chemotherapy.
• Step 5, Follow-up — after treatment, patients undergo regular check-ups, blood tests, CT scans, and gastroscopy at set intervals.

FAQ — Can I Apply These Survival Rate Numbers Directly to My Own Situation?

• No. Survival rates are population averages, not numbers that predict an individual's outcome. Stomach cancer outcomes vary greatly depending on stage, tumor type, age, and coexisting conditions.
• The figures of 78.6% for Korea and 39.8% for the US come from different periods and methodologies—National Cancer Registry Statistics 2019–2023 and SEER 2016–2022, respectively—so they are best used as reference points for general trends rather than precise comparisons.

FAQ — Do Individual Hospitals Publish Their Own Survival Rates?

• Under Korean medical law, individual hospitals' treatment outcomes are not used in advertising. The 78.6% figure cited here comes from nationwide statistics compiled by the Central Cancer Registry at National Cancer Center Korea, not the performance of any specific hospital or physician.
• Individual treatment outcomes vary by stage, tumor type, age, and coexisting conditions, so an accurate assessment can only be made through consultation with the treating medical team.

Sources and Notes

• This article was prepared based on stomach cancer reference notes, National Cancer Registry Statistics 2019–2023 (Central Cancer Registry, National Cancer Center Korea), US SEER data 2016–2022, and patient guideline materials from the National Cancer Information Center and NCCN. Country-by-country data on stomach cancer incidence or case-count rankings were not included in the source material, so that specific question could not be answered.
• This content is provided for general medical information purposes only. Diagnosis, treatment methods, and outcomes may vary depending on individual circumstances. Accurate diagnosis and treatment decisions should always be made in consultation with your medical team.