P03.008 Gastric cancer

Gastric cancer, a malignancy arising from the stomach lining, presents a significant global health burden. Understanding its epidemiology, presentation, diagnosis, and management is crucial for PLAB students.

Epidemiology:

• More common in East Asia, Eastern Europe, and South America.
• Risk factors include:
  • H. pylori infection: Chronic infection with this bacterium is a major risk factor.
  • Diet: High intake of salt, smoked foods, and red meat; low intake of fruits and vegetables.
  • Obesity: Increasing risk with rising BMI.
  • Smoking: Contributes to increased risk.
  • Epstein-Barr virus (EBV) infection: May play a role in some cases.
  • Genetic predisposition: Familial adenomatous polyposis (FAP) and hereditary diffuse gastric cancer (HDGC) syndromes increase risk.

Presentation:

• Often insidious and presents in later stages due to lack of specific symptoms in early stages.
• Common symptoms include:
  • Epigastric pain or discomfort
  • Early satiety (feeling full after eating a small amount)
  • Weight loss
  • Nausea and vomiting
  • Hematemesis (vomiting blood)
  • Melena (black tarry stools)

Diagnosis:

• Endoscopy (Gastroscopy): Upper GI endoscopy with biopsy is the gold standard for diagnosis and allows visualization of the tumor.
• Biopsy: Tissue sample analysis confirms the diagnosis and determines the cancer type.
• Imaging:
  • Upper GI series (barium swallow): May be used initially but less sensitive than endoscopy.
  • CT scan: Provides staging information to assess tumor spread.
  • PET scan: May be used in some cases for further staging evaluation.

Staging:

The TNM staging system classifies gastric cancer based on tumor size (T), lymph node involvement (N), and presence of distant metastasis (M). Stage determines prognosis and treatment options.

PLAB Points to Remember:

• Chronic H. pylori infection is a major risk factor. Consider eradication in high-risk patients.
• Early symptoms can be vague. Maintain a high index of suspicion in patients with risk factors and vague GI complaints.
• Endoscopy with biopsy is the cornerstone of diagnosis.
• Staging with CT scan is crucial for treatment planning.
• Multidisciplinary management involving surgeons, oncologists, and radiotherapists is essential.

Treatment:

• Surgery: Curative intent surgery (gastrectomy) is the mainstay of treatment for localized disease.
• Chemotherapy: Adjuvant (after surgery) or neoadjuvant (before surgery) chemotherapy may be used depending on the stage.
• Radiotherapy: May be used in combination with chemotherapy or as palliative therapy for advanced stages.
• Targeted therapy: Newer targeted therapies are emerging for specific genetic mutations.

Prognosis:

• Prognosis depends on stage at diagnosis. Early detection leads to better outcomes.
• The overall 5-year survival rate varies depending on the stage, ranging from very low for advanced stages to high for localized disease.

Additional Resources:

• National Cancer Institute: https://www.cancer.gov/types/stomach/hp
• American Cancer Society: https://www.cancer.org/cancer/types/stomach-cancer.html
• European Society of Medical Oncology (ESMO) Gastrointestinal Cancers: https://www.esmo.org/meeting-calendar/past-meetings/esmo-world-congress-on-gastrointestinal-cancer-2023