Environmental Protective and Risk Factors for Gastric Cancer: An Umbrella Review and Reanalysis of Meta-Analyses

Area of Science:

• Gastroenterology and Oncology
• Epidemiology
• Public Health

Background:

• Gastric cancer (GC) remains a significant health concern globally.
• Despite extensive research, a consolidated overview of factors influencing GC risk is lacking.
• This study addresses the need for a comprehensive synthesis of GC risk associations.

Purpose of the Study:

• To systematically review and consolidate potential risk factors associated with gastric cancer (GC).
• To provide an overview of GC-associated pairs by reanalyzing existing meta-analyses.
• To evaluate the certainty of evidence for identified GC risk associations.

Main Methods:

• Systematic search of PubMed, Embase, and Cochrane databases up to April 23, 2022.
• Inclusion of 75 systematic reviews and meta-analyses, examining 117 association pairs.
• Reanalysis of data using uniform models and assessment of evidence certainty with GRADE criteria.

Main Results:

• Iatrogenic factors (e.g., antibacterial drugs) and infections (Epstein-Barr virus, Helicobacter pylori) were linked to increased GC risk.
• Human T-lymphotropic virus type 1 (HTLV-1) infection showed a reduced risk association.
• Dietary factors, including heavy alcohol consumption, refined grains, and habitual salt intake, demonstrated significant positive associations with GC risk.

Conclusions:

• Associations between GC risk and dietary/nutritional factors are heterogeneous.
• Lifestyle, iatrogenic, and environmental exposures show consistent associations across regions.
• Region-specific dietary interventions are crucial for effective GC prevention strategies.