Why Does Korea Have the World's Highest Stomach Cancer Incidence Rate? (as of 2026)

The reason Korea is one of the countries diagnosing the most stomach cancer in the world isn't necessarily that the disease itself occurs more often—it's that the national gastroscopy screening program, offered every two years starting at age 40, catches early-stage stomach cancer at a much higher rate. As a result, Korea's 5-year relative survival rate for stomach cancer stands at 78.6% (National Cancer Registration Statistics 2019–2023).

Key Takeaways

• Korea's 5-year relative survival rate for stomach cancer is 78.6% (National Cancer Registration Statistics 2019–2023, National Cancer Center Korea Central Cancer Registry). The combined 5-year relative survival rate for all cancers during the same period is 73.7%.
• The U.S. SEER statistics put the 5-year relative survival rate for stomach cancer at 39.8% (2016–2022)—a substantial gap compared to the Korean figure.
• Both figures represent national-level statistics rather than the performance of any single hospital, and much of the gap stems not only from treatment technology but from how early the cancer is detected.
• Because Korea runs a national gastroscopy screening program every two years from age 40 onward, a relatively high proportion of cases are diagnosed as early-stage stomach cancer.
• Survival rates are population averages, not predictions for any individual case—actual outcomes vary significantly depending on stage, tumor type (histology), age, and comorbid conditions.

Why Does Korea Report So Many Stomach Cancer Diagnoses?

The screening system has a powerful effect on how many cases are 'found.' Because Korea offers national gastroscopy screening every two years starting at age 40, stomach cancer is frequently detected even before symptoms appear. In other words, the phrase 'high incidence rate' doesn't necessarily mean more cancers are actually occurring—it more accurately reflects that screening finds more cases, and finds them earlier. The gap between Korea's 78.6% 5-year relative survival rate (National Cancer Registration Statistics 2019–2023) and the U.S. SEER figure of 39.8% (2016–2022) is explained not just by differences in treatment technology but largely by differences in early-detection rates. This gap cannot be directly translated into predictions for individual outcomes, and even within the same diagnosis of 'stomach cancer,' treatment goals and methods differ entirely depending on stage.

What Difference Does Early Detection Make for Treatment?

Early-stage stomach cancer (confined to the mucosa) can sometimes be treated without removing the stomach at all. Early cancers that are small, well-differentiated, and free of ulceration can be removed via endoscopic submucosal dissection (ESD), which removes only the lesion—since the stomach itself isn't cut, eating habits and daily life are largely preserved. By contrast, surgically resectable stomach cancer—roughly stages 1 through 3—is typically treated with subtotal or total gastrectomy plus lymph node dissection, with stages 2–3 adding adjuvant chemotherapy after surgery or neoadjuvant chemotherapy before surgery. For stage 4 or recurrent stomach cancer that is inoperable or has metastasized, the treatment goal shifts from cure to control, with systemic chemotherapy becoming the central approach and drug selection guided by biomarker test results such as HER2 and PD-L1. Ultimately, early detection works to widen the range of treatment options available.

What Is the Sequence for Diagnosis and Staging?

The starting point for diagnosing stomach cancer is gastroscopy along with an on-the-spot tissue biopsy. Step 1 involves the biopsy confirming whether cancer is present and identifying the tumor type (intestinal or diffuse type, differentiation grade). Step 2 uses abdominal and chest CT to assess the depth of wall invasion, lymph node enlargement, and whether the cancer has spread to other organs. Step 3: when deciding whether endoscopic resection is appropriate for early-stage cancer, endoscopic ultrasound is added, and if peritoneal metastasis is suspected, diagnostic laparoscopy may be performed. Step 4: for advanced or metastatic stomach cancer, biomarker testing for HER2, PD-L1, CLDN18.2, and MSI guides drug selection. Staging follows the TNM system—stage 1 is confined to the shallow layers of the stomach wall with no or minimal lymph node involvement; stages 2–3 involve deeper wall invasion or lymph node involvement; and stage 4 indicates spread to distant organs.

FAQ — Whose Hospital Performance Do Korea's Survival Rate Figures Represent?

These figures represent nationwide statistics for all of Korea, not the performance of any specific hospital (National Cancer Registration Statistics 2019–2023, National Cancer Center Korea Central Cancer Registry). Under Korean medical law, hospital-specific outcome data cannot be used in advertising, and treatment results vary from person to person depending on stage and overall health. The same caveat applies when comparing against statistics from other countries, such as SEER (2016–2022).

FAQ — Can Endoscopy and CT Results from My Own Country Be Used for Remote Review?

Yes. Stomach, abdominal, and chest imaging should be submitted as original DICOM files, along with endoscopy photos and findings, biopsy and pathology reports, and biomarker test results such as HER2, PD-L1, and MSI, if available. If any additional tests are needed, they will be noted in the written opinion.

Sources and Notes

• This article was prepared based on the Stomach Cancer Note (National Cancer Registration Statistics 2019–2023, National Cancer Center Korea; SEER 2016–2022; National Cancer Information Center; NCCN Patient Guidelines) and a related FAQ note.
• This content is intended for general medical information purposes only. Diagnosis, treatment methods, and outcomes may vary depending on individual circumstances. Please be sure to consult with a medical professional to determine accurate diagnosis and treatment.