Tumor markers in cancer patients. an update of their prognostic significance. Part II.

The primary determinant of outcome in patients with cancer is the development of distant metastasis. Metastasis is a multistep process involving disruption of cell-matrix adhesion, dissolution of the extracellular matrix, angiogenesis, invasion in the blood vessel wall, extravasation and establishment of a secondary growth. Nowadays, a large number of biochemical and cell biological studies have indicated the important role of extacellular matrix adhesion molecules, proteinases and angiogenic factors in the dissemination of cancer. Cell adhesion molecules, such as integrins, E-cadherin, catenins and CD44 appear to have some prognostic significance, especially in gastric, colorectal and lung cancer patients. Since matrix degrading proteinases are involved in cancer spread, they should be good candidates as prognostic factors. The proteinase which has been investigated in greatest detail is uPA in breast cancer. As a marker of cancer, its main value is to aid in selecting the subgroups of node-negative breast cancer patients that are unlikely to benefit from adjuvant chemotherapy. Cathepsin D and metalloproteinases (MMPs) look promising prognostic markers but further work is needed to establish their utility. Intratumoral angiogenesis is a putative prognostic indicator for some types of cancer. High expression of the angiogenic factor VEGF is associated with angiogenesis and an unfavourable survival.