Abstract:   Objective  To study the correlation between MMP-9 rs3918242 C>T polymorphism and cancer risk.  Methods  PubMed database was utilized to search the relative artiles concerning association between MMP-9 rs3918242 C>T polymorphism and cancer risk (last search updated on April 2011). All the statistical analysis was performed by STATA software.  Results  4,124 cancer patients and 4,728 control subjects were included in this meta-analysis. No association was observed in the overall analysis (allelic contrast P = 0.378, OR= 0.94, 95% CI：0.83-1.07). However, in the stratified analysis by cancer type, MMP-9 -1562 T allele was found to decrease the lung cancer(P =0.026, OR=0.70，95%CI：0.51-0.96) and colorectal cancer(P = 0.016, OR=0.80，95%CI：0.66-0.96).  Conclusion  MMP-9 rs3918242 C/T polymorphism is correlated with colorectal cancer and lung cancer.

Key words: Matrix metalloproteinase 9, Polymorphism,single nucleotide, Neoplasms, Meta-analysis