Background and purpose:Matrix metalloproteinase11(MMP-11)is an interesting member of the MMP family,and its overexpression has been demonstrated in human cancers such as non-small cell lung cancer and oesophageal adenocarcinoma.Furthermore,strong MMP11 gene expression is correlated with both increased aggressiveness of tumors and a poor clinical outcome,but there was no related reports on gastric cancer.We focussed our study on the significance of MMP-11 expression in gastric cancer.Methods:MMP-11 was selected and confirmed at both mRNA and protein level in 130 cases of gastric cancer serum specimen by RT-PCR,enzyme-linked-immuno-sorbent-assay(ELISA)techniques,respectively.Results:The total positive rates of serum MMP-11 mRNA in gastric cancer and healthy people were 68.4% and 5%,respectively.Our data demonstrated that MMP-11 protein levels in gastric cancer were(44?27)ng/ml,significantly higher than those in control subjects(P=0.001).MMP-11 protein levels in 30 cases with recurrence were(51?27)ng/ml and(27?28)ng/ml in 30 patients without recurrence.MMP-11mRNA positive expression was consistent with MMP-11 protein levels in gastric cancer patients.Conclusions:Serum MMP-11 may play an important role as a biomarker in diagnosis and prediction of recurrent gastric cancer.