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.