What is gastric cancer?

Gastric (stomach) cancer is cancer arising from the lining of the stomach — the large majority (approximately 95%) being adenocarcinomas. It is the 5th most common cancer globally (1.09 million new cases in 2020) and the 4th leading cancer killer (769,000 deaths), with a strikingly unequal global distribution — East Asia, Eastern Europe and parts of Latin America bear a disproportionate burden while high-income Western countries have seen dramatic declines over decades.

What causes gastric cancer?

H. pylori infection is responsible for approximately 89% of gastric cancers — the most important modifiable cause of any cancer. The bacterium causes chronic inflammation → progressive mucosal damage through the Correa cascade over 20-40 years. Additional risk factors: salt-rich diets (pickled, smoked, preserved foods); low fruit and vegetable intake; smoking; heavy alcohol; and occupational exposures. Hereditary forms: hereditary diffuse gastric cancer (CDH1 mutations — 70-80% lifetime risk), Lynch syndrome, gastric adenocarcinoma and proximal polyposis of the stomach (GAPPS).

What are the symptoms?

Early gastric cancer is often asymptomatic or causes only non-specific dyspepsia — which is why most cases are diagnosed late. Warning symptoms that should prompt urgent endoscopy: unexplained weight loss; progressive difficulty swallowing (dysphagia); persistent vomiting; early satiety; haematemesis (vomiting blood) or melaena (black tarry stools); iron-deficiency anaemia without explanation; and palpable epigastric mass. The "alarm feature" approach guides clinicians to investigate promptly.

How does H. pylori eradication prevent gastric cancer?

H. pylori eradication (with 7-14 day antibiotic triple therapy) reduces the progression of pre-malignant lesions (atrophic gastritis, intestinal metaplasia) and reduces gastric cancer incidence by approximately 40-50% in high-risk populations. The benefit is greatest when eradication occurs before pre-malignant changes have developed (before atrophic gastritis). WHO recommends population-level H. pylori test-and-treat in high-prevalence, high-incidence countries as a cost-effective primary prevention strategy.

How is gastric cancer treated?

Localised resectable disease: total or subtotal gastrectomy (D2 lymph node dissection is standard); perioperative FLOT chemotherapy significantly improves survival (FLOT4 trial). HER2-positive advanced disease: trastuzumab + chemotherapy (TOGA trial). HER2-negative advanced disease: pembrolizumab (immunotherapy) is approved for PD-L1-positive (CPS ≥1) disease in first line (KEYNOTE-590 and KEYNOTE-811); VEGF-targeted ramucirumab in second line. Claudin 18.2-targeted zolbetuximab approved for claudin 18.2-positive HER2-negative disease (2024).

Which countries have gastric cancer screening?

Japan has the most established programme — endoscopy or upper GI barium series every 1-2 years for adults 50+ — achieving approximately 30-40% stage I diagnosis rate (vs <10% in unscreened populations). Korea implemented a similar programme in 1999 — reducing gastric cancer mortality by approximately 32%. Both programmes are cost-effective in these high-incidence settings. WHO does not recommend screening in low-prevalence settings (<20 cases per 100,000/year).

What is the role of diet?

High dietary salt consumption (from preserved, salted and pickled foods) is a well-established gastric cancer risk factor — causing gastric mucosal damage and enhancing the carcinogenic effects of H. pylori. Nitrates (from processed meats and some preserved foods) generate carcinogenic N-nitroso compounds in the stomach. Conversely, adequate fruit and vegetable intake (antioxidants, vitamin C) is protective. The striking geographic variation in gastric cancer incidence parallels both H. pylori prevalence and dietary patterns — the decline in Japan and Korea partly reflects dietary westernisation and refrigeration replacing salt preservation.

Is gastric cancer increasing in young people?

Like colorectal cancer, early-onset gastric cancer (before age 50) is increasingly recognised — with non-cardia gastric cancer (H. pylori-associated) increasing in some high-income country birth cohorts. The diffuse type, associated with CDH1 germline mutations and increasingly with E-cadherin somatic changes, disproportionately affects young women. Young patients with new-onset upper GI symptoms should not have symptoms dismissed on the basis of age.

How does GMJ News cover gastric cancer?

GMJ News covers GLOBOCAN gastric cancer data, H. pylori eradication as cancer prevention, HER2 testing and trastuzumab evidence, new immunotherapy approvals and Georgia's gastric cancer burden. Georgia has among the highest gastric cancer rates in the Caucasus — directly relevant to PHIG's cancer prevention programme and the Georgian Medical Journal.

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Gastric Cancer

Q: What is the role of diet?

High dietary salt consumption (from preserved, salted and pickled foods) is a well-established gastric cancer risk factor — causing gastric mucosal damage and enhancing the carcinogenic effects of H. pylori. Nitrates (from processed meats and some preserved foods) generate carcinogenic N-nitroso compounds in the stomach. Conversely, adequate fruit and vegetable intake (antioxidants, vitamin C) is protective. The striking geographic variation in gastric cancer incidence parallels both H. pylori prevalence and dietary patterns — the decline in Japan and Korea partly reflects dietary westernisation and refrigeration replacing salt preservation.

Q: Is gastric cancer increasing in young people?

Like colorectal cancer, early-onset gastric cancer (before age 50) is increasingly recognised — with non-cardia gastric cancer (H. pylori-associated) increasing in some high-income country birth cohorts. The diffuse type, associated with CDH1 germline mutations and increasingly with E-cadherin somatic changes, disproportionately affects young women. Young patients with new-onset upper GI symptoms should not have symptoms dismissed on the basis of age.

Q: How does GMJ News cover gastric cancer?

GMJ News covers GLOBOCAN gastric cancer data, H. pylori eradication as cancer prevention, HER2 testing and trastuzumab evidence, new immunotherapy approvals and Georgia's gastric cancer burden. Georgia has among the highest gastric cancer rates in the Caucasus — directly relevant to PHIG's cancer prevention programme and the Georgian Medical Journal.

GMJ News knowledge hub · last reviewed September 2026 · Georgian Medical Journal

Summary Statistics Glossary GMJ news FAQ Documents Organizations Research

Gastric (stomach) cancer is the 5th most common cancer globally and the 4th leading cause of cancer death — causing approximately 769,000 deaths from 1.09 million new cases in 2020 — with the vast majority (approximately 89%) attributable to a single preventable cause: Helicobacter pylori infection (IARC GLOBOCAN 2020). Gastric cancer has declined dramatically in high-income countries over the past 50 years — driven by declining H. pylori prevalence (from improved hygiene and antibiotic access), reduced salt and smoked food consumption, and refrigeration. However, it remains a leading cancer killer in East Asia, Eastern Europe, Latin America and parts of Africa, where H. pylori infection remains endemic.

Key messages

769,000 deaths — 89% from H. pylori

Gastric cancer kills approximately 769,000 people per year from 1.09 million new cases. Approximately 89% are attributable to H. pylori infection — making it the most preventable major cancer through infection control (IARC GLOBOCAN 2020 / WHO).

H. pylori — the most common carcinogen

Helicobacter pylori — infecting approximately 50% of the world's population — is classified as a Group 1 carcinogen by IARC. It causes chronic atrophic gastritis → intestinal metaplasia → dysplasia → gastric adenocarcinoma over decades.

H. pylori eradication prevents cancer

Treating H. pylori infection reduces gastric cancer risk by approximately 40-50% in population studies. WHO recommends H. pylori test-and-treat strategies as a cost-effective gastric cancer prevention approach.

East Asia bears the highest burden

Japan, Korea, China and Mongolia have the world's highest gastric cancer incidence — driven by high H. pylori prevalence, salt-rich diets (pickled/salted foods) and smoking. Korea and Japan have implemented successful gastric cancer screening programmes.

Late diagnosis drives poor survival

Overall 5-year survival for gastric cancer is approximately 20-25% — because most cases are diagnosed at stage III or IV. Early-stage gastric cancer (Stage I-II) has >95% 5-year survival in countries with early detection programmes (Japan, Korea).

Screening works in high-prevalence settings

Japan and Korea have implemented population-based gastric cancer screening — endoscopy or upper GI barium radiography every 1-2 years — achieving approximately 30-40% reduction in gastric cancer mortality. Not cost-effective in low-prevalence settings.

Key statistics

1.09M

new gastric cancer cases/year (2020)

IARC GLOBOCAN

769K

gastric cancer deaths/year (2020)

IARC GLOBOCAN

89%

of gastric cancer attributable to H. pylori

IARC/WHO

50%

of global population infected with H. pylori

WHO

40-50%

cancer risk reduction with H. pylori eradication

WHO/Cochrane

leading cause of cancer death globally

IARC 2020

Gastric cancer age-standardised incidence (per 100,000) by region — GLOBOCAN 2020

Source: IARC GLOBOCAN 2020. East Asia and Eastern Europe dominate global gastric cancer burden.

Glossary of key terms

Helicobacter pylori
IARC/WHOA Gram-negative spiral bacterium colonising the gastric mucosa — infecting approximately 50% of the world's population. IARC Group 1 carcinogen. Causes chronic active gastritis, peptic ulcer disease, and — through the Correa cascade — gastric adenocarcinoma. Transmitted faecal-orally, primarily in childhood.

Correa cascade
WHO/ClinicalThe sequence of progressive gastric mucosal changes from H. pylori infection → chronic gastritis → atrophic gastritis → intestinal metaplasia → dysplasia → intestinal-type gastric adenocarcinoma. This process takes 20-40 years — providing multiple intervention windows.

Gastric adenocarcinoma
WHO/IARCThe most common gastric cancer type (approximately 95%) — divided into intestinal type (glandular, often H. pylori-associated, better prognosis) and diffuse type (poorly cohesive cells — including signet ring cell, often HER2-negative, worse prognosis, more common in young women).

HER2 in gastric cancer
TOGA trial/FDAHER2 overexpression/amplification occurs in approximately 20% of gastric and gastroesophageal junction (GEJ) adenocarcinomas. Trastuzumab (Herceptin) added to first-line chemotherapy improves overall survival in HER2-positive advanced gastric cancer (TOGA trial). HER2 testing is now standard at diagnosis.

H. pylori test-and-treat
WHO/ESGEStrategy of testing for H. pylori and treating those positive — without endoscopy — as a pragmatic population health measure. WHO recommends test-and-treat in populations with >20-30% H. pylori prevalence as a gastric cancer prevention strategy.

FLOT regimen
ESMO/ASCOFluorouracil + leucovorin + oxaliplatin + docetaxel — the current standard perioperative chemotherapy for resectable gastric cancer (FLOT4 trial), replacing the older ECF/ECX regimens. Perioperative FLOT significantly extends survival vs surgery alone.