Early stomach cancer

Disease Description (Causes and Symptoms)

• Definition: Early gastric cancer refers to gastric cancer in which cancer cells are confined to the gastric mucosa or submucosa (regardless of lymph node metastasis); compared with advanced gastric cancer, it involves shallower invasion of the gastric wall and has favorable treatment outcomes.
• Causes·pathophysiology: The exact mechanism of onset is unknown, but the following factors are associated:
  • Helicobacter pylori (H. pylori) infection (positive findings have been reported in approximately 40–60% of all patients)
  • Precancerous lesions such as chronic atrophic gastritis, intestinal metaplasia, and gastric adenoma
  • Environmental carcinogens such as a high-salt diet, nitrate-containing foods, smoked or charred foods, and smoking
  • Increased risk of cancer developing over a long period (average 15–20 years) in the remnant stomach after partial gastrectomy
• Main symptoms: Most patients are asymptomatic or commonly have mild indigestion, upper abdominal discomfort, or nausea. Rarely, hematemesis or melena may occur. Because the symptoms resemble those of common gastric diseases, diagnosis may be delayed.

Treatment Methods

• Diagnostic evaluation: Upper gastrointestinal endoscopy and biopsy (confirmation of diagnosis), endoscopic ultrasonography (EUS) to assess the depth of invasion, abdominal CT/MRI/PET/abdominal ultrasonography to assess metastasis and surrounding invasion, and an upper gastrointestinal contrast study to confirm the location and appearance of the lesion.
• Endoscopic treatment
  • Standard: Endoscopic submucosal dissection (ESD) is widely used as the standard non-resection treatment for early gastric cancer. It is applied when the lesion is confined to the mucosa and the risk of lymph node metastasis is low.
  • Examples of indications (general criteria): differentiated histology, no ulceration, confinement to the mucosa, and size limitation (traditionally ≤2 cm, although expanded criteria exist). These may vary depending on the characteristics of each lesion.
  • Complications: Bleeding and perforation may occur — immediate endoscopic hemostasis and closure or surgery may be required.
• Surgical treatment
  • Partial gastrectomy or radical gastrectomy (laparoscopic or open) with lymph node dissection (generally at the D1/D2 level). This is performed when the patient does not meet the indications for endoscopic treatment or lymph node metastasis is suspected.
  • Laparoscopic surgery may be considered when conservative resection is possible from the perspective of quality of life.
• Adjuvant therapy
  • Adjuvant chemotherapy is generally unnecessary for early gastric cancer with no lymph node metastasis.
  • If lymph node metastasis or signs of progression are present, adjuvant anticancer therapy may be recommended depending on the stage and histological findings.
• Lifestyle management and precautions
  • Smoking cessation, a low-salt diet, and consumption of fresh foods are recommended. Limit alcohol and foods that are highly heated or smoked.
  • If H. pylori infection is confirmed, eradication therapy may be considered (preventive treatment may be discussed depending on family history and the condition of the stomach).
  • After endoscopic treatment, visit a medical institution immediately if symptoms of bleeding or perforation occur, such as severe abdominal pain, fever, or persistent bleeding.
• Prognosis: For early gastric cancer confined only to the mucosa, the 5-year survival rate after appropriate treatment is favorable, at over 90%.

Checklist Before an Outpatient Visit (Including Items to Bring and Sample Questions)

• Items to bring (for consultations and examinations)
  • List of medications currently being taken (including aspirin/anticoagulants) and allergy history
  • Previous test results (endoscopy findings, pathology reports, abdominal CT/MRI results, etc.) or imaging films
  • Symptom record: onset, frequency, presence of bleeding (hematemesis or melena), weight changes, and appetite changes
  • Surgical history (especially whether you have had stomach surgery) and family history (whether there is a history of gastric cancer)
• Items to check before the consultation
  • Recent changes in weight and food intake, characteristics of abdominal pain, and the frequency and triggers of nausea and vomiting
  • Whether anticoagulants are being taken (important before endoscopic biopsy or procedures)
• Possible examinations during the outpatient visit: Additional endoscopy, repeat biopsy, EUS, abdominal CT, etc.

Examples of General Questions to Ask the Doctor

• “How will the exact stage of my lesion (depth of invasion and possibility of lymph node metastasis) be assessed?”
• “Which treatment option is appropriate for me—endoscopic resection or surgery? What are the advantages and disadvantages?”
• “What is my prognosis (recurrence rate and survival rate)? What will the schedule for follow-up examinations be after treatment?”
• “If I am taking a medication such as an anticoagulant, how should it be managed during endoscopy?”
• “Do I need H. pylori testing and eradication therapy? Does eradication reduce the risk of recurrence?”

Examples of Disease-Specific Questions

• “Is my lesion likely to be cured with endoscopic resection? (Request an explanation based on lesion size, histological type, and whether ulceration is present.)”
• “The pathology results indicate ‘submucosal invasion’ or ‘lymphatic invasion.’ In this case, what is the risk of lymph node metastasis, and what additional treatment is recommended?”