Association between MMP1 -1607 1G>2G polymorphism and head and neck cancer risk: a meta-analysis.

BACKGROUND: MMP1 is an important member of the MMP endopeptidase family that plays a critical role in the development of head and neck cancer (HNC). Several studies have investigated the association between the MMP1 -1607 1G>2G polymorphism and risk of HNC, but their results have been inconsistent. Here, we conducted a meta-analysis to further explore the role of the MMP1 -1607 1G>2G polymorphism in HNC development. METHODS: We identified all eligible studies in the electronic databases of PubMed, ISI Web of Knowledge, MEDLINE, Embase, and Google Scholar (from January 2000 to June 2012). A meta-analysis was performed to evaluate the association between the MMP1 -1607 1G>2G polymorphism and risk of HNC by calculating odds ratios (OR) and 95% confidence interval (CIs). RESULTS: Twelve studies were included in this meta-analysis. In overall comparison, significant associations were found using the recessive and allelic contrast models (OR, 1.38; 95% CI, 1.07-1.79 and OR, 1.27; 95% CI, 1.05-1.53, respectively), but no association was detected using the dominant model. In the stratified analyses by several variables, significant associations were observed using the recessive, dominant, and allelic contrast models in the Asian population (OR, 1.64; 95% CI, 1.29-2.08; OR, 1.39; 95% CI, 1.06-1.82; and OR, 1.41; 95% CI, 1.21-1.65, respectively), European population (OR, 0.58; 95% CI, 0.40-0.84; OR, 0.64; 95% CI, 0.44-0.92; and OR, 0.68; 95% CI, 0.54-0.85, respectively), and population-based subgroup (OR, 1.24; 95% CI,1.05-1.47; OR,1.48; 95% CI,1.04-2.12; and OR, 1.22; 95% CI, 1.07-1.38, respectively). Furthermore, significant associations were detected in oral cavity cancer and nasopharyngeal cancer under the recessive model. CONCLUSION: Our results suggest that the MMP1 -1607 1G>2G polymorphism is associated with risk of HNC and that it plays different roles in Asian and European populations. Further studies with large sample size are needed to validate our findings

Begg’s funnel plot for publication bias test.

<p>Each point represents a separate study for the indicated association under the recessive model.</p

Forest plot for association between <i>MMP1</i>-1607 1G>2G and risk of HNC under the recessive model (2G/2G VS 1G/1G+1G/2G).

<p>A random effects model was used. The <i>squares</i> and <i>horizontal lines</i> represent the study-specific OR and 95% CI. The <i>diamonds</i> correspond to the summary OR and 95% CI.</p

Forest plot for association between <i>MMP1</i>-1607 1G>2G and risk of HNC under the allelic contrast model (2G VS 1G).

<p>A random effects model was used. The <i>squares</i> and <i>horizontal lines</i> represent the study-specific OR and 95% CI. The <i>diamonds</i> correspond to the summary OR and 95% CI.</p

Stratified analysis of <i>MMP1</i> -1607 1G>2G polymorphism and HNC risk.

a<p>Number of comparisons,</p>b<p>P-value for Q-test.</p>c<p>Random-effects model was used when P-value of Q-test for heterogeneity <0.05; otherwise fixed-effects model was used.</p>d<p>HB: hospital-based,</p>e<p>PB: population-based,</p>*<p>Statistically significant, with P<0.05.</p

Flow diagram of study identification.

<p>Flow diagram of study identification.</p