Stomach Cancer: Detecting the Silent Threat

Gastric cancer (stomach cancer) is one of the most significant cancers worldwide. It ranks as the 5th most common cancer and the 4th leading cause of cancer-related deaths globally. The incidence varies by region, with the highest rates found in East Asia, including Korea, Japan, and China.

Although gastric cancer is less common in Thailand compared to other cancers, a major concern is that many patients are diagnosed at an advanced stage, leading to a relatively high mortality rate.

However, understanding the risk factors and recognizing early warning signs can lead to early detection, timely treatment, improved outcomes, and a greater chance of cure.

Who Is at Risk?

Several factors increase the risk of developing gastric cancer:

• Age: More common in individuals over 40–50 years old

• Ethnicity: Higher prevalence in East Asian populations

• Family History: Having first-degree relatives (parents, siblings, or children) with gastric cancer significantly increases risk

• Helicobacter pylori (H. pylori) Infection: A major cause of gastric cancer. This bacterium leads to chronic inflammation of the stomach lining, which may eventually develop into cancer. The World Health Organization (WHO) recommends treatment upon detection to reduce cancer risk

• Lifestyle Factors: Smoking, heavy alcohol consumption, and obesity

• Dietary Habits:

  • Frequent consumption of pickled or high-salt foods, which may contain nitrates that can convert into carcinogenic nitrosamines

  • High salt intake may irritate the stomach lining, leading to chronic inflammation and increased cancer risk

  • Eating uncooked or unhygienic food, which may be contaminated with H. pylori

Symptoms of Gastric Cancer

Early Stage

Symptoms may be absent or resemble gastritis, such as:

• Upper abdominal discomfort or indigestion (dyspepsia)

• Mild nausea

Advanced Stage

Symptoms often include persistent upper abdominal pain along with alarm features, such as:

• Gastrointestinal bleeding (black stools, blood in stool, or vomiting blood)

• Iron-deficiency anemia

• Early satiety (feeling full quickly)

• Persistent vomiting, especially after meals

• Unexplained weight loss

Diagnostic Methods

1. Upper Gastrointestinal Endoscopy (EGD: Esophagogastroduodenoscopy)

This is the most effective method for detecting abnormalities in the stomach. It allows physicians to:

• Directly visualize tumors or lesions

• Identify the exact location

• Perform a biopsy for pathological confirmation

The procedure typically takes 15–20 minutes.

2. CT Scan of the Whole Abdomen

If cancer is detected via endoscopy, a CT scan is performed to:

• Evaluate the spread of cancer to other organs

• Help guide treatment planning

Treatment Options

Treatment depends on the stage of the disease:

• Stages 1–3 (Early Stages):
  Surgery is the main treatment. In some cases, chemotherapy and/or radiation therapy may be added to reduce recurrence risk

• Stage 4 (Advanced/Metastatic Stage):
  At this stage, cancer has spread to other organs such as the peritoneum, liver, or lungs. Surgical cure is not possible. Treatment focuses on:

  • Chemotherapy to control disease progression

  • Improving survival and quality of life

In some patients, newer treatments such as targeted therapy and Immunotherapy, may be used to improve survival outcomes

Prevention

• Treat gastritis completely, especially H. pylori infection, and follow up to ensure eradication

• Avoid high-nitrate foods such as pickled, processed, and heavily salted foods

• Consume well-cooked, clean, and hygienic food

• Avoid smoking and excessive alcohol consumption

• Exercise regularly and maintain a healthy weight

Who Should Be Screened for Gastric Cancer?

• Individuals over 50 years old with new-onset dyspepsia

• Patients with persistent gastritis symptoms that do not improve after 1–2 months of treatment (or within 2 weeks in some cases)

• Individuals with a family history of gastric cancer

• Patients with dyspepsia accompanied by alarm symptoms, such as:

  • Vomiting blood or black stools

  • Unexplained weight loss

  • Iron-deficiency anemia

  • Loss of appetite, early satiety, or persistent vomiting