Active specific immunotherapy for colorectal cancer

With advances in molecular biology and the identification of tumor-associated antigens, a number of new strategies have been developed in an attempt to overcome the limits of chemotherapy and to aid in the fight to cure patients of metastatic and micrometastatic colorectal carcinomas. Biological therapy has now moved into the era of immunotherapy. Nonspecific immunotherapy has been surpassed by modalities that produce a specific and potent immune response against identifiable tumor-associated antigens, so called active specific immunotherapy. Approaches that come under this heading include tumor cell vaccines, anti-idiotypic antibody therapy and dendritic cell vaccines. Cells can be further boosted by the use of immunostimulatory cytokines. This review aims to evaluate current strategies of immunotherapy for colorectal cancer with particular emphasis on the clinical aspects.