Gastric cancer is a malignant tumor that originates in the cells of the stomach lining. In East Asia (including Hong Kong), the incidence of gastric cancer is significantly higher than in Western countries, which is related to dietary culture and a higher rate of Helicobacter pylori infection. Early-stage gastric cancer causes almost no symptoms, and many patients are already at an advanced stage when diagnosed. This is why understanding the risk factors and warning signs is especially important.
Although gastric cancer may sound frightening, advances in endoscopic techniques, surgical methods, and drug treatments mean that early-stage gastric cancer has a high cure rate, and there are more and more treatment options for advanced disease as well.
Causes and Risk Factors
Helicobacter pylori infection is one of the most important risk factors for gastric cancer. This bacterium causes chronic gastritis, which over time can lead to atrophy of the gastric mucosa and cancerous changes. In terms of diet, frequently eating pickled, smoked, and high-salt foods (such as salted fish and pickled vegetables) increases risk; insufficient intake of fresh fruits and vegetables, smoking, and excessive alcohol consumption are also risk factors.
Other risk factors include: increasing age (most common in people over 50), male sex, a family history of gastric cancer, pernicious anemia, previous stomach surgery, and precancerous conditions such as chronic atrophic gastritis or gastric polyps.
Common Symptoms and Warning Signs
Early-stage gastric cancer mostly causes no obvious symptoms, or only mild indigestion, bloating, and loss of appetite, which are easily dismissed as an ordinary stomach problem. This is also the main reason gastric cancer is often diagnosed late.
More noticeable warning signs include: persistent upper abdominal pain or a burning sensation, feeling full after eating only a small amount (early satiety), difficulty swallowing (when the tumor is near the cardia), vomiting or vomiting blood, black stools (a sign of stomach bleeding), unexplained anemia, weight loss, and fatigue. If these symptoms persist, you should arrange for an examination as soon as possible.
Diagnosis and Staging
Upper endoscopy (gastroscopy) is the most direct way to diagnose gastric cancer. The doctor can observe the stomach lining through the scope and take tissue samples from suspicious areas for confirmation. For high-risk individuals (such as those with chronic atrophic gastritis), regular endoscopy monitoring helps detect cancer early.
After diagnosis, a CT scan, endoscopic ultrasound (EUS), or laparoscopy is used to assess the depth of invasion and whether the cancer has spread. Staging ranges from stage I (confined to the superficial layers of the stomach wall) to stage IV (distant metastasis). Staging directly determines the treatment strategy: early-stage disease may be treated with endoscopic resection or surgery, while advanced disease requires comprehensive treatment.
Overview of Treatment Options
Surgery is the main method of curing gastric cancer. Depending on the tumor's location and extent, part or all of the stomach is removed, along with nearby lymph nodes. Very early-stage gastric cancer can even be removed with endoscopic submucosal dissection (ESD) without open surgery. Chemotherapy is often given before or after surgery to improve the chance of a cure.
Advanced gastric cancer is mainly treated with drugs: chemotherapy is the foundation, and patients who are HER2-positive may receive an anti-HER2 targeted therapy. In recent years, combinations of immunotherapy (PD-1 inhibitors) and chemotherapy have become a first-line option for some patients with advanced disease; drugs targeting new targets such as Claudin 18.2 are also being introduced. Biomarker testing (HER2, PD-L1, MSI, etc.) before treatment is very important for choosing the right regimen.
Clinical Trials: One More Treatment Option
Gastric cancer is one of the key cancer types in international new drug development. Drugs targeting new targets (such as Claudin 18.2 and FGFR) and immunotherapy combination strategies are constantly being tested in clinical trials. Joining a clinical trial gives patients the chance to use these new therapies earlier.
The CancerLink platform can screen for gastric cancer clinical studies currently recruiting in Hong Kong based on cancer type, stage, and genetic mutations. Once successfully matched and enrolled, all study-related treatment costs are covered. If you would like to learn more about your options, feel free to browse the site or submit a matching request.
When facing gastric cancer, remember two things: first, do not delay when you have persistent stomach discomfort — endoscopy is a quick way to clarify the cause; second, even after diagnosis, modern gastric cancer treatment offers multiple layers of options including surgery, drugs, and clinical trials. Work with your medical team to develop the plan that suits you best.