Enterohemorrhagic Escherichia coli infection

Disease Description (Causes and Symptoms)

• Definition summary: Advanced gastric cancer refers to a stage in which cancer cells have invaded beyond the gastric submucosa into the muscular layer or deeper, with a high possibility of metastasis to the lymph nodes around the stomach or to adjacent organs such as the liver, pancreas, transverse colon, and spleen, as well as distant metastasis through the bloodstream or lymphatic system.
• Causes and risk factors:
  • Helicobacter pylori (H. pylori) infection (positive findings in approximately 40–60% of all patients)
  • Chronic atrophic gastritis, intestinal metaplasia, gastric adenoma, and pernicious anemia (precancerous gastric lesions)
  • High-salt foods, smoked foods, nitrates (carcinogens), and charred meat/fish
  • Smoking (increased risk of gastric cancer)
  • Previous partial gastrectomy (increased risk 15–20 years after surgery)
  • Family history
• Pathophysiology summary:
  • The cancer begins in the mucosa, invades the submucosa and muscular layer, and metastasizes to surrounding lymph nodes and distant organs through the lymphatic vessels and blood vessels. It may perforate the gastric wall and spread to the peritoneum (peritoneal seeding).
• Main symptoms (as the disease progresses):
  • Weight loss, loss of appetite, persistent indigestion, upper abdominal discomfort and bloating, and abdominal pain
  • Anemia and fatigue caused by hematemesis, melena, or gastrointestinal bleeding
  • Vomiting (when the pylorus is obstructed), dysphagia (when the cardia is involved)
  • Abdominal mass, palpable intra-abdominal lymph nodes, and hepatomegaly (in the event of metastasis)
• Emergency warning symptoms (requiring immediate medical attention): inability to eat because of persistent vomiting, massive bleeding (hematemesis/melena), and sudden weight loss or symptoms of severe anemia

Treatment Methods

• Surgical treatment
  • If complete resection is possible, radical surgery (partial gastrectomy or total gastrectomy) and standard lymph node dissection (such as D2 lymph node dissection) are the basic treatments.
  • The extent of resection and lymph node dissection is determined according to the extent of metastasis and the patient’s condition.
• Chemotherapy
  • Adjuvant therapy: Used to reduce the risk of recurrence after surgery.
  • Neoadjuvant therapy: Used to shrink the tumor before surgery.
  • Systemic treatment (palliative): Used to extend survival and relieve symptoms in patients who cannot undergo surgery or have distant metastases.
  • Main drug classes: fluoropyrimidines (5‑FU, capecitabine), platinum agents (oxaliplatin, cisplatin), taxanes, irinotecan, and others.
• Targeted therapy and immunotherapy
  • For HER2-positive disease, combination therapy with trastuzumab may be considered.
  • In the second or third line, VEGFR2 inhibitors (e.g., ramucirumab) and immune checkpoint inhibitors (pembrolizumab, nivolumab, etc.) may be used based on specific biomarkers such as MSI-high/dMMR or PD-L1.
• Radiation therapy
  • Used as an adjuvant treatment after surgery or as palliative radiation therapy to relieve pain, bleeding, or local symptoms.
• Palliative care
  • Endoscopic stent placement for pyloric obstruction, nutritional support (enteral or parenteral nutrition), pain and bleeding control, blood transfusion, and other treatments.
• Side effects and precautions (including self-care)
  • Surgical complications: bleeding, infection, fistula, and impaired nutrient absorption (dumping syndrome and nutritional deficiencies after gastrectomy)
  • Chemotherapy side effects: vomiting, diarrhea, bone marrow suppression (risk of infection, anemia, and bleeding), neuropathy, nephrotoxicity, and others—regular blood tests and symptom monitoring are necessary
  • Targeted therapy/immunotherapy side effects: cardiotoxicity (HER2 treatment) and possible immune-related adverse events (involving the liver, lungs, endocrine organs, etc.)—early reporting and management are essential
  • Nutritional management: nutritional counseling to prevent weight loss and protein deficiency, with supplementation if necessary (in consultation with a dietitian)
  • Smoking cessation and a low-salt diet are recommended, along with eating fresh foods

Checklist Before an Outpatient Visit (Including Preparation Items and Example Questions)

• Items to prepare (recommended to bring)
  • A list of currently used medications (including prescription drugs, over-the-counter drugs, and supplements) and a history of allergies
  • Previous test results (gastroscopy findings and biopsy results/pathology findings), surgical records, and imaging results and reports (CT/MRI/PET)
  • Records of recent weight changes and changes in food intake, vomiting, and bowel movements
  • Recent blood test results (CBC, liver and kidney function tests, etc.), if available
  • Insurance card and primary physician’s contact information
• Symptoms to record before the outpatient visit
  • Whether bleeding (hematemesis or melena) has occurred and its frequency, the pattern of vomiting (frequency and contents), and whether dysphagia is present
  • Location and intensity of pain, aggravating factors, and whether fever, jaundice, or shortness of breath is present
• Questions for the patient to prepare and ask at the outpatient visit (examples)
  • "How should I manage my recent weight and nutritional status?"
  • "Is surgery possible, and if so, what would be the expected extent of resection and complications?"

Examples of General Questions to Ask the Doctor

• "Could you explain my exact cancer stage, including the status of local invasion, lymph nodes, and distant metastasis?"
• "What are the recommended first-line treatment options, and what are the expected benefits and side effects of each treatment?"
• "Which tests need to be monitored during chemotherapy, and how often should they be performed?"
• "What special precautions should I take regarding nutrition, exercise, and daily life?"

Examples of Disease-Specific Questions

• "What are the results of my HER2, PD‑L1 (CPS), and MSI/dMMR tests? Am I eligible for targeted therapy or immunotherapy?"
• "Is complete resection possible in my case? If resection is possible, what is the appropriate extent of D1 versus D2 lymph node dissection, and how long is the expected recovery period?"

(If an emergency occurs or symptoms suddenly worsen, contact the emergency room or your primary physician immediately. Individual treatment plans and the indications for tests and treatment are determined according to the judgment of the treating medical team.)