MMP-2 as a putative biomarker for carcinomatosis in gastric cancer

Background/Aims: We evaluated matrix metalloproteinase (MMP)-2 and -9 as novel biomarkers in the body fluid of advanced gastric cancer with peritoneal and pleural metastasis. Methodology: MMPs activity from zymography was quantified with ELISA to determine the cut-off expression levels of MMPs. The expression of MMPs in patient samples were evaluated with ELISA and compared with clinical parameters. Ascitic CEA (aCEA) and pleural CEA (pCEA) were measured by chemiluminescent enzyme immunoassay. Results: MMP-2 and -9 cut-off levels were 8.6ng/mL and 0.14ng/mL, respectively. Ascitic fluid cytology of 93 patients revealed a positivity of 55.9% while for MMP-2 it was 93.3%, for MMP-9 35.2% and for aCEA 86.7%. Combining biomarkers, the positivity increased to 99.1% in patients with MMP-2 and aCEA expression. We found a negative correlation between MMP-2 expression and survival when a new prognostic cut-off of 22.6ng/mL was used. Patients with high MMP-2 expression (≥22.6ng/mL) had a median survival of 45 days and those with low MMP-2 expression (<22.6ng/mL) had a median survival of 69 days (p<0.01). Conclusions: These results suggest that MMPs could be used as diagnostic markers in body fluid and MMP-2 might be a prognostic marker in ascites of advanced gastric patients with disseminated metastasis.