Gastric Cancer: Risk Factors, Diagnosis and Treatment

Gastric cancer (stomach cancer) is the fifth most common cancer globally, with approximately 1.1 million new cases and 770,000 deaths each year — making it the fourth leading cause of cancer mortality worldwide. The geographic distribution is strikingly unequal: East Asia — particularly China, Japan, and South Korea — accounts for approximately 60% of all global gastric cancer cases. China alone contributes approximately 40% of worldwide gastric cancer incidence.

Despite advances in treatment, the majority of gastric cancers are diagnosed at an advanced stage in most countries, when curative treatment is no longer possible. The 5-year survival for localised gastric cancer exceeds 60–70%; for metastatic disease, it remains below 10% — making early detection by endoscopy the most impactful strategy in high-incidence regions.

Anatomy and Cancer Types

The stomach is divided into the cardia (adjacent to the oesophago-gastric junction), fundus (upper left), body (corpus), antrum (lower), and pylorus (junction with duodenum). Cancer location affects prognosis and treatment:

• Gastric adenocarcinoma — accounts for >90% of all gastric cancers; arises from glandular epithelial cells; the focus of this guide
• Gastro-oesophageal junction (GOJ) / cardia cancers — anatomically and biologically distinct; treatment similar to oesophageal cancer
• Gastric lymphoma (MALT) — mucosa-associated lymphoid tissue lymphoma; closely linked to H. pylori; often cured by H. pylori eradication alone
• Gastrointestinal stromal tumour (GIST) — arises from interstitial cells of Cajal; treated with imatinib rather than conventional chemotherapy

Causes and Risk Factors

Helicobacter pylori (H. pylori)

H. pylori is the dominant cause of non-cardia gastric cancer — a gram-negative spiral bacterium that colonises the gastric mucosa, triggering chronic inflammation, atrophic gastritis, intestinal metaplasia, dysplasia, and ultimately adenocarcinoma (the Correa cascade). H. pylori infection is estimated to be responsible for approximately 89% of non-cardia gastric cancers worldwide.

The World Health Organization classified H. pylori as a Group 1 (definite) carcinogen. Approximately 50% of the global population is infected; prevalence reaches 50–70% in China. Eradication with antibiotics + proton pump inhibitor reduces gastric cancer risk by approximately 35–40%.

Diet

• High salt intake — disrupts gastric mucosal defences; the very high salt diet in traditional East Asian cuisine (pickled vegetables, salted fish, fermented foods) correlates with regional gastric cancer rates
• Nitrosamines — formed from nitrates in smoked, cured, and processed meats
• Low fruit and vegetable intake — antioxidant vitamins C and E are protective
• Alcohol — modest dose-dependent association

Other Risk Factors

• Age — most cases occur >60; median diagnosis age approximately 68
• Male sex — 2× higher incidence in men
• Smoking — approximately 1.5–2× increased risk
• First-degree family history — 2–3× increased risk; hereditary diffuse gastric cancer (CDH1 gene mutation) carries very high lifetime risk in affected families
• Atrophic gastritis and intestinal metaplasia — pre-malignant conditions detectable by endoscopy; require surveillance
• Pernicious anaemia — autoimmune gastritis destroying parietal cells; raises gastric cancer risk 3–6×
• Prior gastric surgery — post-gastrectomy stump cancer risk increases after 15–20 years
• Obesity — particularly for cardia/GOJ cancers

Symptoms

Early gastric cancer is almost always asymptomatic — or produces only non-specific dyspepsia indistinguishable from gastritis or peptic ulcer disease. This is why endoscopic screening is crucial in high-risk populations.

Symptoms of locally advanced gastric cancer:

• Persistent upper abdominal pain or discomfort — epigastric pain not relieved by antacids
• Unintentional weight loss — often substantial (5–10+ kg) by the time of diagnosis
• Anorexia — progressive loss of appetite
• Dysphagia — difficulty swallowing (cardia or GOJ tumours)
• Early satiety — feeling full after small amounts of food (linitis plastica — diffuse infiltrative cancer stiffening the stomach)
• Nausea and vomiting — particularly with pyloric obstruction
• Iron deficiency anaemia — chronic occult bleeding
• Haematemesis or melaena — visible upper GI bleeding (less common at presentation)
• Palpable abdominal mass — advanced disease
• Signs of metastasis: Virchow's node (left supraclavicular lymph node); Sister Mary Joseph nodule (periumbilical metastasis); Krukenberg tumour (ovarian metastasis)

Alarm features requiring urgent endoscopy (in any patient >45 with new dyspepsia):

• Unintentional weight loss
• Dysphagia
• Progressive difficulty eating
• Persistent vomiting
• Iron deficiency anaemia
• Haematemesis

Diagnosis

Upper GI Endoscopy (Gastroscopy)

The essential diagnostic investigation. A flexible endoscope is passed under conscious sedation through the mouth into the stomach and duodenum. The gastric mucosa is systematically inspected, and any suspicious lesion is biopsied.

Advanced endoscopic techniques improve detection of early gastric cancer:

• Narrow-band imaging (NBI) — highlights mucosal vascular patterns
• Chromoendoscopy — spraying indigo carmine or acetic acid delineates lesion margins
• Magnification endoscopy — high-magnification assessment of mucosal pit patterns

H. pylori Testing

All patients with gastric cancer or its precursors should be tested and treated for H. pylori. Tests: ¹³C-urea breath test (gold standard), stool antigen, serology, or rapid urease test on gastric biopsy.

Staging

Once gastric adenocarcinoma is diagnosed histologically:

CT chest/abdomen/pelvis — identifies locoregional lymph node involvement and distant metastases (liver, peritoneum, lungs). The most important staging test.

Endoscopic ultrasound (EUS) — high-frequency ultrasound through the endoscope assesses depth of invasion (T stage) and perigastric lymph node involvement (N stage); critical for selecting patients for endoscopic resection vs surgery.

PET-CT — useful to exclude occult distant metastases in patients planned for curative surgery; less sensitive for peritoneal disease.

Diagnostic laparoscopy — recommended before curative gastrectomy to exclude peritoneal metastases not detectable on CT; peritoneal washings sent for cytology.

Molecular profiling on biopsy:

• HER2 (ERBB2) status — 12–20% of gastric cancers overexpress HER2; indicates eligibility for trastuzumab (anti-HER2 antibody) in advanced disease
• MMR/MSI testing — microsatellite instability-high (MSI-H) tumours respond well to immunotherapy (pembrolizumab)
• PD-L1 (CPS score) — predicts benefit from immune checkpoint inhibitors

TNM Staging and Prognosis

Stage	Description	5-Year Survival
IA	T1 (lamina propria/submucosa), N0, M0	~94%
IB	T1N1 or T2N0	~88%
IIA–IIB	T2–3, N0–2	50–70%
IIIA–IIIC	T3–4, N1–3	15–40%
IV	Any distant metastasis	~5%

Treatment

Endoscopic Resection (Early Gastric Cancer)

For tumours confined to the mucosa or superficial submucosa (T1a/T1b) without lymph node involvement:

Endoscopic mucosal resection (EMR) — cap-assisted snare resection; for small, flat lesions ≤2 cm.

Endoscopic submucosal dissection (ESD) — dissection beneath the submucosa allows en bloc resection of larger lesions; the standard in Japan and increasingly in China. ESD achieves curative resection of early gastric cancer in over 90% of selected cases with minimal morbidity and no impact on quality of life. Developed and perfected in Japan; rapidly becoming the standard at high-volume Chinese centres.

Surgery

Total gastrectomy — removal of the entire stomach with lymph node dissection; used for proximal, body, or diffuse cancers.

Distal (subtotal) gastrectomy — preserves the upper stomach; preferable for distal cancers; equivalent oncological outcomes with better nutritional tolerance.

D2 lymph node dissection — the surgical standard in East Asia (removing the second-tier of regional lymph nodes); associated with lower local recurrence and improved survival compared to limited D1 dissection.

Minimally invasive approaches: laparoscopic and robotic gastrectomy have become the standard at high-volume East Asian centres for resectable disease — equivalent oncological outcomes to open surgery with faster recovery.

Perioperative Chemotherapy

For resectable non-metastatic gastric cancer (stage IB–III):

FLOT (docetaxel + oxaliplatin + leucovorin + 5-FU) — the current European/international standard for perioperative (pre- and post-operative) chemotherapy; the FLOT4 trial demonstrated 50% 5-year survival vs 36% with older regimens.

Neoadjuvant chemotherapy — downstages tumours before surgery; allows curative resection of initially unresectable disease; assesses chemosensitivity.

Adjuvant chemotherapy — post-surgical S-1 (oral fluoropyrimidine) or capecitabine + oxaliplatin (CAPOX) — standard in East Asian guidelines (particularly for D2-resected patients).

Advanced/Metastatic Gastric Cancer

First-line:

• Platinum + fluoropyrimidine + nivolumab (PD-1 inhibitor) — the CheckMate 649 trial: addition of nivolumab to FOLFOX/CAPOX improved median OS from 11.1 to 13.8 months; now standard first-line for PD-L1 CPS ≥5
• Trastuzumab + chemotherapy — for HER2-positive tumours (ToGA trial: OS 13.8 vs 11.1 months); trastuzumab deruxtecan (T-DXd) approved for HER2-positive second-line

Immunotherapy:

• Pembrolizumab for MSI-H gastric cancer (first-line or second-line)
• Nivolumab ± ipilimumab for MSI-H or CPS ≥10 tumours

Gastric Cancer Care in China

China's gastric cancer centres offer:

• Diagnostic gastroscopy: high-definition magnification endoscopy with NBI, EUS for T/N staging, and CT staging
• ESD and EMR expertise: China's leading endoscopy centres have accumulated among the highest volumes of ESD globally — same technology and surgical technique as Japan's leading centres
• Robotic and laparoscopic D2 gastrectomy: specialist upper GI surgeons performing hundreds of gastrectomies annually with outcomes comparable to Japanese and South Korean series
• Full molecular profiling: HER2, MMR/MSI, PD-L1, EBV testing
• Access to all systemic regimens: FLOT chemotherapy, trastuzumab, nivolumab, pembrolizumab; domestic Chinese biosimilar antibodies available
• H. pylori eradication programme: testing and 14-day triple/quadruple therapy with confirmation of eradication
• Cost: care in China is generally less expensive than UK private treatment, but the hospital prices each case individually — ask us for the written quote before you commit.
• Full English care navigation from endoscopy through staging, surgery, and oncological treatment

Contact a ChinaMedicalTour care navigator to arrange a gastroscopy, gastric cancer assessment, or treatment consultation.

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Medical content based on MSD Manuals and international gastric cancer guidelines (ESMO, NCCN, JGCA). Evidence reviewed 2025.

Frequently Asked Questions

How do Chinese tertiary centers evaluate international gastric cancer cases before admission?

Patients can provide foreign endoscopic reports, biopsy histopathology, and contrast-enhanced CT scans for a multidisciplinary team (MDT) pre-consultation involving surgical oncology, medical oncology, and pathology specialists.

What surgical approaches are offered for gastric cancer in high-volume Chinese centers?

Tertiary gastrointestinal surgery departments perform laparoscopic and robot-assisted radical gastrectomy with D2 lymphadenectomy, organ-preserving resections, and perioperative systemic chemotherapy based on tumor stage and clinical guidelines.

How are hospital costs and treatment durations confirmed?

Hospital billing follows official public hospital rate schedules. A detailed written quotation is issued directly by the hospital based on the confirmed clinical care plan and required inpatient stay.