Yuhua Gong1, Benjuan Wei1, Li Yu1, Weijuan Pan2. 1. Department of Stomatology, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China. 2. Department of Stomatology, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China. Electronic address: weijpan@126.com.
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.
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.