Expression of MMP-9 and TIMP-1 as prognostic markers in gastric carcinoma.

BACKGROUND/AIMS: The aim of the present work is to clarify the role of metalloproteinase-9 and its inhibitor in the evolution of gastric cancer after surgical resection.

METHODOLOGY

We have studied 44 gastric cancer patients submitted to surgery. There were 13 proximal tumors, 16 located in the middle third and 15 in the distal one. Overall survival was 26% at 6 years. Metalloproteinase-9 and tissue inhibitor of metalloproteinase concentrations were investigated by means of ELISA in frozen samples of tumoral and normal gastric mucosa.

RESULTS

Mean concentration of metalloproteinase-9 in tumoral tissue was 42 ng/mg of total protein, and this value was 6.9 times greater than the mean concentration in non-tumoral tissue. Cancer tissue also expressed higher levels of TIMP-1, 7.25 versus 4.39 ng/mg of protein. Higher levels of metalloproteinase expression in tumoral tissue, greater [metalloproteinase in tumor]/[metalloproteinase in non-tumor] ratio and greater [metalloproteinase]/[inhibitor] ratio in tumor cells, were all of them statistically related to a worse prognosis when T1 and T2 tumors were considered.

CONCLUSIONS

The expression of metalloproteinase-9 or its inhibitor is related to a more aggressive phenotype of gastric cancer.