Body mass index and risk of gastric cancer: a meta-analysis.

Objective: Overweight and obesity, indicated as increased body mass index, are associated with the risk of some cancers. We carried out a meta-analysis on published cohort and case-control studies to assess the strength of association between body mass index and gastric cancer.

Methods: Relevant studies were identified through PubMed, Web of Science and Medline electronic databases. Adjusted relative risks (odds ratios) with 95% confidence interval were used to assess the strength of association between body mass index and gastric cancer.

Results: Sixteen eligible studies were included in this meta-analysis. Overall, obesity (body mass index ≥ 30 kg/m(2)) was associated with an increased risk of gastric cancer (odds ratio = 1.13, 95% confidence interval = 1.03-1.24) compared with normal weight (body mass index = 18.5 to <25 kg/m(2)), while overweight (body mass index = 18.5 to <30 kg/m(2)) showed no association (odds ratio = 1.04, 95% confidence interval = 0.96-1.12). Specifically, a stratified analysis showed there were associations between obesity and the increased risk of gastric cancer for males (odds ratio = 1.27, 95% confidence interval = 1.09-1.48), non-Asians (odds ratio = 1.14, 95% confidence interval = 1.02-1.28) and both cohort studies (odds ratio = 1.10, 95% confidence interval = 1.00-1.22) and case-control studies (odds ratio = 1.29, 95% confidence interval = 1.03-1.60). Both overweight (odds ratio = 1.22, 95% confidence interval = 1.05-1.42) and obesity (odds ratio = 1.61, 95% confidence interval = 1.15-2.24) were associated with the increased risk of gastric cardia cancer.

Conclusions: The results indicated that obesity was associated with the risk of gastric cancer, especially for males and among non-Asians. Both overweight and obesity were associated with the risk of gastric cardia cancer.