What is Stomach Cancer?
Stomach cancer develops when normal cells in the stomach lining begin to grow abnormally. The most common type, adenocarcinoma, accounts for the vast majority of stomach cancers. The disease typically progresses through a long sequence: chronic inflammation → atrophic gastritis → intestinal metaplasia → cellular dysplasia → cancer. This multi-year process means stomach cancer does not appear overnight – there is a window for intervention.
While stomach cancer rates have been gradually declining in Western countries, it remains one of the leading causes of cancer incidence and cancer-related deaths across the Asia-Pacific region.
Risk Factors
Dietary Habits
Regular consumption of salt-pickled, soy sauce-cured, stir-fried, grilled, smoked, or deep-fried foods increases risk.
H. pylori Infection
Infection with Helicobacter pylori bacteria is a major risk factor for stomach cancer development.
Pre-Cancerous Conditions
Gastric adenomatous polyps, atrophic gastritis with intestinal metaplasia, achlorhydria, pernicious anaemia, and remnant stomach after partial gastrectomy.
Genetic Factors
Individuals with a family history of stomach cancer have a significantly higher risk. Approximately 10% of stomach cancer patients have a family history of the disease.
Symptoms
Stomach cancer does NOT have "specific" symptoms.
Early-stage stomach cancer patients often show no specific symptoms. The signs – upper abdominal pain, bloating, poor appetite, black stools – are indistinguishable from benign conditions such as chronic gastritis, peptic ulcers, or functional gastrointestinal disorders. A positive faecal occult blood test or black stools may be mistaken for ulcer bleeding. Some pain may be temporarily relieved by antacids.
Late-stage stomach cancer patients begin to experience weight loss, loss of appetite, fatigue, difficulty swallowing, persistent vomiting, and massive ascites.
Because early-stage stomach cancer rarely has symptoms, countries with high incidence rates (such as Japan and South Korea) use regular screening examinations to detect stomach cancer early.
Who Should Get Screened?
If you have high-risk factors for stomach cancer or a family history of stomach cancer, in addition to paying attention to your dietary habits, you should undergo regular gastroscopy examinations to enable early detection and early treatment.
Diagnosis
The primary diagnostic method is upper gastrointestinal endoscopy (gastroscopy) with biopsy and histopathological examination. While upper GI barium swallow X-ray can also show lesion size and location, it typically only identifies larger or deeper lesions, and may miss small or superficial ones. Moreover, doctors often cannot determine from X-ray alone whether a lesion is benign or malignant. Therefore, when stomach cancer is suspected, gastroscopy with tissue biopsy is essential.
Treatment Options
Endoscopic Mucosal Resection (EMR)
For early-stage stomach cancer where the tumour is confined to the mucosal epithelial layer or lamina propria, and the location and size are suitable, endoscopic removal can be performed – avoiding the trauma of traditional open surgery.
Surgical Resection
Radical surgical resection remains the primary treatment option with the potential for cure for stomach cancer patients.
Chemotherapy
In the past decade, chemotherapy has become widely used in oncology. It can achieve tumour remission, prolong survival in responders, and is now considered standard treatment for inoperable or metastatic stomach cancer.
Targeted Therapy
Targeted cancer therapy is a new era in oncology. By selectively targeting cancer cells while minimising impact on normal cells, targeted therapy typically has lower toxicity than conventional chemotherapy.
Prevention
Preventing stomach cancer begins with dietary habits. Foods containing high levels of carcinogens – such as smoked, salt-pickled, or charcoal-grilled items – should be avoided for regular or long-term consumption. Food storage should prioritise refrigeration or freezing. Regular intake of fresh fruits and vegetables rich in Vitamin C can help reduce the formation and activation of carcinogens.
For individuals known to be infected with H. pylori who have not yet progressed to atrophic gastritis, undergoing H. pylori eradication therapy is an important strategy in preventing stomach cancer development. For those with high-risk factors or family history of stomach cancer, in addition to watching dietary habits, regular gastroscopy screening is recommended to enable early detection and early treatment.