Stomach (Gastric) Cancer

Gastric cancer develops through a precancerous cascade: chronic gastritis from H. pylori leads to atrophy, metaplasia, dysplasia, and invasion. Genetic mutations in APC, TP53, and Kras genes accumulate over decades. Risk factors encompass smoking, pickled foods, obesity, and family history, with higher incidence in Asia.?

Symptoms and Stages

Early gastric cancer often shows no symptoms or mild dyspepsia, delaying diagnosis until advanced stages with abdominal pain, anorexia, vomiting blood, or weight loss. It progresses from stage 0 (inner lining) to stage IV (metastasis to liver or nodes), with poor prognosis in late detection. Adenocarcinomas dominate, classified as intestinal or diffuse types.?

Diagnosis and Treatment

Endoscopy with biopsy confirms diagnosis, staging via CT or PET scans. Treatment involves gastrectomy for early cases, plus chemotherapy (e.g., fluorouracil) or radiation; targeted therapies target HER2-positive tumors. Five-year survival exceeds 70% in Japan due to screening, versus under 30% elsewhere.