Meta-Analysis
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World J Gastroenterol. Oct 28, 2013; 19(40): 6902-6910
Published online Oct 28, 2013. doi: 10.3748/wjg.v19.i40.6902
Diabetes mellitus carries a risk of gastric cancer: A meta-analysis
Shouji Shimoyama
Shouji Shimoyama, Gastrointestinal Unit, Settlement Clinic, Tokyo 120-0003, Japan
Author contributions: Shimoyama S solely contributed to this paper.
Correspondence to: Shouji Shimoyama, MD, Gastrointestinal Unit, Settlement Clinic, 4-20-7, Towa, Adachi-ku, Tokyo 120-0003, Japan. shimoyama@apost.plala.or.jp
Telephone: +81-3-36057747 Fax: +81-3-36050244
Received: May 14, 2013
Revised: June 27, 2013
Accepted: July 30, 2013
Published online: October 28, 2013
Abstract

AIM: To investigate the association and quantify the relationship between diabetes mellitus (DM) and gastric cancer (GC) by an updated meta-analysis.

METHODS: The initial PubMed search identified 1233 publications. Studies not reporting GC or those not reporting actual number of GC were excluded. Twelve pertinent studies were retrieved from the PubMed database or from a manual search and considered for the meta-analysis. Pooled risk ratios and 95%CI were estimated by a random-effects model. Subgroup analysis was performed according to gender or geographical regions. Heterogeneity and publication bias were evaluated by I2 and funnel plot analysis, respectively.

RESULTS: DM was significantly associated with GC with a RR of 1.41 (P = 0.006) (95%CI: 1.10-1.81). Subgroup analyses revealed that both sexes showed a significant association with GC, with a greater magnitude of risk in females (RR = 1.90; 95%CI: 1.27-2.85; P = 0.002) than in males (RR = 1.24; 95%CI: 1.08-1.43; P = 0.002). In addition, the link between DM and GC was significant in East Asian DM patients (RR = 1.77; 95%CI: 1.38-2.26; P < 0.00001) but not in Western DM patients (RR = 1.23; 95%CI: 0.90-1.68; P = 0.2). There was no evidence of publication bias, but the results indicated significant heterogeneity.

CONCLUSION: This updated meta-analysis has provided evidence of positive DM-GC associations. The limited information on potentially important clinical confounding factors in each study deserves further investigation.

Keywords: Gastric cancer, Diabetes mellitus, Meta-analysis, Hyperglycemia, Hyperinsulinemia

Core tip: Diabetes mellitus (DM) was significantly associated with gastric cancer (GC) with a risk ratio of 1.41. This positive DM-GC association was also observed in both sexes with a greater magnitude of risk in females than male, and in East Asian patients but not in Western patients. This study could provide one answer to current inconsistent knowledge across trials concerning a positive/inverse DM-GC association. Since DM patients are less likely to be screened for cancers, clinicians caring for DM patients should remain alert to detect GC especially in females, since there are fewer female than male GC patients in the general population.