Advanced gastric cancer (Advanced gastric cancer)
1) Disease description (causes and symptoms)
- Definition and pathophysiology: Gastric cancer that has invaded beyond the submucosal layer into the muscular layer or deeper; it may be accompanied by regional lymph node involvement or distant metastases to the liver, peritoneum, lungs, bones, and other sites. Tumor infiltration and metastasis can cause penetration of the stomach wall, lymphatic and hematogenous metastasis, and peritoneal dissemination.
- Main causes and risk factors: Helicobacter pylori infection (strong association), a high-salt diet, nitrates, smoked foods, smoking, precancerous lesions such as chronic atrophic gastritis, intestinal metaplasia, and gastric adenoma, long-term changes in the gastric remnant after gastrectomy, and family history.
- Main symptoms: Upper abdominal discomfort or pain, indigestion or early satiety, loss of appetite, weight loss, nausea and vomiting (when the pylorus is obstructed), dysphagia (when the cardia is involved), hematemesis and melena (in the event of bleeding), and anemia. As the disease progresses, an abdominal mass, palpable intra-abdominal lymph nodes, hepatomegaly, and other findings may be observed.
2) Treatment methods and precautions
- Surgery
- When curative resection (partial or total gastrectomy) and standard lymph node dissection (D2) are possible, they are the standard of curative treatment. The extent of surgery is determined after preoperative staging.
- When metastasis or peritoneal dissemination is present, curative surgery may not be possible. Multimodal treatment, such as resection of liver metastases, may be considered in some selected patients.
- Chemotherapy
- Used as adjuvant therapy (to prevent recurrence after surgery) and neoadjuvant therapy (to shrink the tumor before surgery). In patients with unresectable or metastatic disease, it is administered as first-line treatment.
- Commonly used drugs/regimens include fluorouracil (5-FU)-based drugs, oxaliplatin, capecitabine, cisplatin, S-1 (used in Korea and East Asia), irinotecan, and others.
- Targeted therapy: In HER2-positive cases, combination treatment with trastuzumab is standard (for metastatic disease).
- Immune checkpoint inhibitors: PD-1-class antibodies (e.g., nivolumab and pembrolizumab) may be used depending on specific biomarkers (MSI-H, PD-L1, etc.) or available treatment options.
- Radiation therapy
- Used for adjuvant or palliative purposes (control of residual lesions after surgery, relief of pain and bleeding, and relief of intestinal obstruction symptoms).
- Endoscopic and interventional procedures
- Stent placement to relieve symptoms caused by narrowing of the gastric lumen, enteral feeding tubes (jejunal feeding) for nutritional support, and other procedures.
- Symptom management and nutrition
- In patients with advanced disease, management of weight loss, malnutrition, and anemia is important. Consultation with a dietitian and supplemental nutrition (enteral or parenteral nutrition) may be considered.
- Precautions (risk of complications and self-management)
- There is a risk of bleeding, perforation, and obstruction, as well as decreased organ function due to metastasis (in the liver, lungs, bones, etc.) and postoperative nutritional absorption problems (dumping syndrome and vitamin deficiencies).
- Monitoring is necessary for chemotherapy side effects (nausea, bone marrow suppression, nephrotoxicity, neurotoxicity, etc.) and radiation-related side effects.
- Regular surveillance and active symptom relief (pain management, intravenous fluids, blood transfusions, etc.) are recommended.
3) Checklist before an outpatient visit (items to bring, records, and example questions)
- Items/documents to bring
- A list of current medications and nutritional supplements (including doses and administration times)
- Previous test results (endoscopy and biopsy reports, CT/MRI/PET reports), and records of surgeries, hospitalizations, and medications
- Records of recent symptom changes, weight changes (by time period), meal intake, and vomiting frequency
- Records of allergy history and chronic diseases (such as cardiovascular or kidney disease)
- Outpatient visit checklist (things to record)
- Recent pain (location, intensity, and frequency), bleeding (hematemesis and melena), and whether dysphagia or vomiting is present
- Changes in urination or bowel movements, and whether fever or shortness of breath is present
- Whether side effects occurred after chemotherapy (nausea, diarrhea, numbness in the hands and feet, fever, etc.)
4) Examples of general questions to ask the doctor
- What is the stage of my disease, and what is the goal of treatment (curative vs. palliative)?
- What treatment options do you recommend, and what are their expected benefits and risks?
- What side effects can be expected from chemotherapy, targeted therapy, or immunotherapy, and how can they be managed?
- How should I manage my nutrition, and when should nutritional therapy be started if I lose weight?
- How should I respond if pain, bleeding, or obstruction symptoms develop during treatment?
- What is the follow-up testing schedule (endoscopy, CT, etc.) and how often will tests be performed?
5) Examples of disease-specific questions
- What are the results of HER2, MSI, PD-L1, and HER2 testing in the pathology examination of my tumor, and do these results make targeted therapy or immunotherapy possible?
- If surgery is possible at my current stage, do you recommend neoadjuvant chemotherapy (chemotherapy before surgery)? If so, what is the expected treatment duration and what complications may occur?
(Note: The diagnosis and treatment plan vary depending on the individual's stage, histological characteristics, overall condition, and the institution's treatment policies. Please consult your treating medical team regarding specific decisions.)