PROTEASES AS PROGNOSTIC MARKERS IN CANCER

It is the ability to invade and metastasize that ultimately determines the prognosis in cancer, Comprising one of the key groups of molecule s involved in invasion and metastasis are proteases such as urokinase plasminogen activator and cathepsins B, D, and L, as well as various m etalloproteases. These proteases catalyze degradation of the interstit ial matrix and basement membranes, allowing cancer cells to invade loc ally and metastasize to distant sites, If proteases are directly and c ausally involved in cancer spread, they have the potential to be new p rognostic markers in cancer, One of the best examples of a correlation between high levels of a protease in a primary tumor and poor prognos is is urokinase plasminogen activation in breast cancer. In this malig nancy, the urokinase plasminogen activator is a strong and independent prognostic marker and may be a marker for axillary node-negative dise ase, The urokinase plasminogen activator may also be a prognostic mark er in other cancers such as gastric, colorectal, lung, bladder, cervic al, and ovarian cancers, In a number of studies, cathepsin D has been shown to be a prognostic factor in breast cancer, However, results wit h cathepsin D, especially when immunocytochemistry Is used for its det ection, are conflicting, Levels of cathepsin B, cathepsin L, and certa in metalloproteases may also supply prognostic data in certain cancers , but results with these proteases are still preliminary.