Purpose: A previous meta-analysis (MA) published in 2009 reported that excess body weight was associated with an increased risk of gastric cancer in non-Asians, but not in Asians. The aim was to conduct a meta-epidemiological MA (MEMA) to evaluate association between excess body weight and the risk of gastric cancer in Asian adults with using the proposed classification of weight by body mass index (BMI) in Asian adults.
Materials and methods: The selection criteria were population-based prospective cohort studies that measured BMI of cohort participants and evaluated a risk of gastric cancer. Overweight group (OW) and obesity group (OB) were defined as 23.0-24.9 and ≥ 25.0, respectively. A group only showing results for BMI over 23.0 was defined as overweight and obesity group (OWB). Random effect model was applied if I2 value was over 50%.
Results: After four new studies were added through citation discovery tools, seven cohort studies with 21 datasets were selected finally for MEMA. The I2 value of OW, OB, and OWB were 76.1%, 83.5%, and 97.1%, respectively. Only OWB in men had a I2 value below 50% (22.5%) and showed a statistical significance with inverse association (summary relative risk, 0.79; 95% confidence interval, 0.77 to 0.81).
Conclusion: This MEMA supported the hypothesis that OW might be a protective factor in gastric cancer risk in Asian adults. It will be necessary to conduct additional cohort studies with lengthening follow-up periods and re-analyzing the effect of overweight and obesity classified by the Asian criteria.
Keywords: Gastric neoplasms; Meta-analysis; Obesity; Overweight; Systematic review.