Type 2 diabetes mellitus and risk of oral cancer and precancerous lesions: a meta-analysis of observational studies

Oral Oncol. 2015 Apr;51(4):332-40. doi: 10.1016/j.oraloncology.2015.01.003. Epub 2015 Jan 31.

Abstract

Objective: Associations between type 2 diabetes mellitus (type 2 DM) and risk of oral cancer and precancerous lesions have been reported with controversial findings. We performed a meta-analysis to explore these associations.

Methods: We identified studies by a literature search of MEDLINE and EMBASE through May 31, 2014, and by searching the reference lists of pertinent articles. Summary relative risk (SRR) with 95% confidence interval (CI) was calculated with a random-effects model. Between- study heterogeneity was assessed using the Cochran's Q and I(2) statistics.

Results: A total of 13 studies (4 case-control and 9 cohort studies) on the association between type 2 DM and oral cancer were included. Overall analysis found that compared with non-diabetic individuals, individuals with type 2 DM had a significantly elevated incidence of oral cancer (SRR=1.15, 95% CI: 1.02-1.29; Pheterogeneity=0.277, I(2)=15.4%; 10 studies). Subgroup analyses found that duration of follow-up (⩾11years) significantly altered this positive association. Type 2 DM was associated with increased oral cancer mortality (SRR=1.41, 95% CI: 1.16-1.72; 4 studies). Meta-analysis of the four case-control studies showed a positive association between type 2 DM and risk of oral precancerous lesions (SRR=1.85, 95%CI: 1.23-2.80; Pheterogeneity=0.038, I(2)=57.5%). No significant public bias was found across these studies.

Conclusions: These findings of this meta-analysis indicate that compared with non-diabetic individuals, individuals with type 2 DM have an elevated risk of oral cancer and precancerous lesions development.

Keywords: Meta-analysis; Oral cancer; Precancerous lesions; Type 2 diabetes mellitus.

Publication types

  • Meta-Analysis

MeSH terms

  • Diabetes Mellitus, Type 2 / complications*
  • Humans
  • Mouth Neoplasms / complications*
  • Precancerous Conditions / complications*
  • Risk Factors