Association between MMP-9 -1562 C/T polymorphism and susceptibility to digestive cancers: A meta-analysis

Matrix metalloproteinases (MMPs) play important roles in tumorigenesis. The variant in MMP-9 -1562 C/T (single nucleotide polymorphisms labeled rs3918242) has been extensively evaluated as predisposing factors to digestive cancers susceptibility. However, most of these studies only contained a small number of subjects and they showed conflicting results. Therefore, to elucidate these associations, we carried out a large-scale meta-analysis to provide this accurately comprehensive synopsis of case-control studies.

A comprehensive literature search was conducted in EMBASE, OVID, Medline, China National Knowledge Internet and Wanfang for relevant data published between Jan 2000 and Mar 2018. Overall and stratified analyses based on the cancer types, ethnicity and source of control were carried out. Odds ratios (ORs) correspondent to 95% confidence intervals (95% CIs) were calculated to evaluate the genetic correlation between the variant and digestive cancer susceptibility. Review Manager 5.2 and Stata 12.0 were used for statistical analysis.

Twenty studies containing 3201 digestive cancer patients and 4301 matched-controls were screened out. The overall results suggested that MMP-9 -1562 C/T polymorphism increased the susceptibility to digestive cancers under homozygote and recessive models (homozygote, OR = 1.35, 95% CI 1.00-1.82, P = 0.05; recessive, OR = 1.42, 95% CI 1.07-1.88, P = 0.02). Furthermore, in the subgroup analysis based on the source of control, similar conclusions were obtained in the population-based control subgroup (homozygote, OR = 1.63, 95% CI 1.16-2.27, P = 0.004; recessive, OR = 1.67, 95% CI 1.22-2.28, P = 0.001), but not in the hospital-based control. In subgroup analyses based on cancer types and ethnicity, no association was observed.

Our meta-analysis suggested that MMP-9 -1562 C/T polymorphism might be related to the digestive cancer susceptibility. Evidence with adequate sample size is needed.