Risk Factors for Gastric Cancer

Infectious Factors

• H. pylori infection is the most well-established risk factor for gastric cancer, increasing risk approximately 2.5-fold (with some studies showing up to 6-fold increased risk) 3, 4
• H. pylori causes persistent active gastritis that may progress to atrophic gastritis, intestinal metaplasia, and eventually gastric cancer 3

Demographic and Genetic Factors

• Male gender is associated with approximately twice the risk compared to females 5, 6
• Age is a significant risk factor, with peak incidence in the seventh decade of life 5, 2
• Family history of gastric cancer in first-degree relatives increases risk 2-3 fold 3, 1
• Specific genetic syndromes significantly increase risk 2

Dietary and Lifestyle Factors

• Diets low in fresh fruits and vegetables increase risk of gastric cancer 3
• High salt consumption is strongly associated with increased risk 3
• Diets high in processed foods, processed meats, and red meat increase risk 1
• Smoking increases gastric cancer risk, though the magnitude is less than for lung cancer 3, 7

Medical Conditions

• Pernicious anemia significantly increases risk through its relationship with chronic atrophic gastritis 4
• Previous gastric resection for benign disease increases risk 3
• Chronic atrophic gastritis and intestinal metaplasia are important precursors for malignant transformation 3, 5
• Menetrier's disease (a rare condition with enlarged gastric folds) increases risk 6

Socioeconomic and Geographic Factors

• Geographic variation is substantial, with highest rates in East Asia, South America, and Eastern Europe 5, 2
• Early-generation immigrants from high-incidence regions (Eastern Europe, Andean Latin America, East Asia) have elevated risk 1, 8
• Persistent poverty is associated with 43% higher gastric cancer mortality rates 1, 8
• Obesity is increasingly recognized as a risk factor, particularly for gastric cardia cancer 6

Important Clinical Considerations

• Patients with multiple risk factors should be considered for endoscopic screening, especially if they are 45 years or older 1, 8
• H. pylori eradication is the most promising strategy for primary prevention of gastric cancer 4
• Alarm symptoms that warrant prompt investigation include dysphagia, weight loss, anemia, anorexia, and persistent dyspepsia, especially in those over 55 years 3, 7