Biliopancreatic malignancy: Future prospects for progress

Several key areas are targeted by novel therapies. Growth factors and their receptors are overexpressed in a high percentage of pancreatic tumors. The se factors are critical to tumor cell growth and development. They also pro mote tumor growth by stimulating angiogenesis. Mutations in other molecules that regulate cell growth, such as the ras protein and the tumor suppresso r p53, contribute to a state of continously stimulated cell proliferation. Other types of molecules such as mucins are also altered or overexpressed i n tumors. Mucins are immunosuppressive and are important in tumor cell meta stasis. A number of promising new therapeutic strategies are now being tested. Ribo zymes or antisense nucleic acids can prevent synthesis of growth factor rec eptors or ras protein, Monoclonal antibodies block interaction between rece ptor and its ligand. Newly developed drugs prevent tyrosine phosphorylation of growth factor receptors or farnesylation of ras protein. Gene therapy i s another approach that is under investigation. Transduction or transfectio n of genes for wild-type tumor suppressors could correct defects in growth regulation. Vaccines developed against tumor antigens provide hope for the control of not only the primary tumor, but also of the metastatic lesions a s well.