Matrix metalloproteinases and their tissue inhibitors in gastric cancer as molecular markers

Gastric cancer is a complex disease that involves a range of biological individuals and tumors with histopathological features. The pathogenesis of this disease is multi-factorial and includes the interaction of genetic predisposition with environmental factors. Gastric cancer is normally diagnosed in advanced stages where there are few alternatives to offer and the prognosis is difficult to establish. Metastasis is the leading cause of cancer deaths. Identification of key genes and signaling pathways involved in metastasis and recurrence could predict these events and thereby identify therapeutic targets. In this context, the extracellular matrix metalloproteinases (MMPs) and their inhibitors (TIMPs) represent a potential prognostic tool, because both genetic families regulate growth, angiogenesis, invasion, immune response, epithelial mesenchymal transition and cellular survival. Proteolytic parameters based on MMP/TIMP expression could be useful in the identification of patients with a high probability of developing distant metastases or peritoneal dissemination for each degree of histological malignancy. It is also probable that these parameters can allow improvement in the extent of surgery and dictate the most suitable therapy. We reviewed papers focused on human gastric epithelial cancer as a model and focus on the potential use of MMPs and TIMPs as molecular markers; also we include literature regarding gastric cancer risk factors, classification systems and MMP/TIMP regulation.