BACKGROUND: The prognostic role of matrix metalloproteinase-9 (MMP-9) in metastatic gastric cancer has not been validated. PATIENTS AND METHODS: We carried out a molecular analysis in 222 metastatic gastric cancer patients obtained from clinical trials. We assessed the messenger RNA (mRNA) expression of MMP-9, vascular endothelial growth factor receptor-A, and epidermal growth factor receptor in a training cohort of 130 patients and conducted an independent validation in 92 patients. Automated RNA extraction from paraffin and RT-quantitative PCR was used. Immunohistochemistry for MMP-9 and diverse immune cell infiltrates was conducted. RESULTS: In the training cohort, only MMP-9 significantly correlated with patient's survival. At the cut-off with the highest predictive value, 19% of patients had MMP-9 expression above this cut-off and these showed a median survival of 3.6 months compared with 10.5 months (P=1.7e(-6)) in patients with lower expression. Corresponding 1- and 2-year survivals were 9% and 44% and 0 and 21%, respectively. The application of this cut-off to the validation cohort revealed similar distributions of overall survival according to MMP-9 expression on uni- (P<0.001) and multivariate analyses (P<0.001). No differences in survival according to MMP-9 below best cut-off were found. MMP-9 protein assessed by immunohistochemistry was not prognostic. CONCLUSION: MMP-9 mRNA expression above a certain cut-off level is associated with dismal survival.
BACKGROUND: The prognostic role of matrix metalloproteinase-9 (MMP-9) in metastatic gastric cancer has not been validated. PATIENTS AND METHODS: We carried out a molecular analysis in 222 metastatic gastric cancerpatients obtained from clinical trials. We assessed the messenger RNA (mRNA) expression of MMP-9, vascular endothelial growth factor receptor-A, and epidermal growth factor receptor in a training cohort of 130 patients and conducted an independent validation in 92 patients. Automated RNA extraction from paraffin and RT-quantitative PCR was used. Immunohistochemistry for MMP-9 and diverse immune cell infiltrates was conducted. RESULTS: In the training cohort, only MMP-9 significantly correlated with patient's survival. At the cut-off with the highest predictive value, 19% of patients had MMP-9 expression above this cut-off and these showed a median survival of 3.6 months compared with 10.5 months (P=1.7e(-6)) in patients with lower expression. Corresponding 1- and 2-year survivals were 9% and 44% and 0 and 21%, respectively. The application of this cut-off to the validation cohort revealed similar distributions of overall survival according to MMP-9 expression on uni- (P<0.001) and multivariate analyses (P<0.001). No differences in survival according to MMP-9 below best cut-off were found. MMP-9 protein assessed by immunohistochemistry was not prognostic. CONCLUSION:MMP-9 mRNA expression above a certain cut-off level is associated with dismal survival.
Authors: Derek C Marshall; Susan K Lyman; Scott McCauley; Maria Kovalenko; Rhyannon Spangler; Chian Liu; Michael Lee; Christopher O'Sullivan; Vivian Barry-Hamilton; Haben Ghermazien; Amanda Mikels-Vigdal; Carlos A Garcia; Brett Jorgensen; Arleene C Velayo; Ruth Wang; Joanne I Adamkewicz; Victoria Smith Journal: PLoS One Date: 2015-05-11 Impact factor: 3.240