Immune surveillance as a rationale for immunotherapy?

The majority of pathogen vaccines are used within the prophylactic setting as opposed to the therapeutic setting proposed for cancer vaccines. Due to the intricate role of the immune system in tumorigenesis, tumor immunotherapy may have to borrow approaches from autoimmunity. The size of the malignant population that has to be eliminated, the associated immunosuppressive effects of the tumor, the diversion of inflammatory and immune processes by the organized stroma surrounding the tumor, the antigenic diversity of the tumor cell population leading to immune escape, all present barriers that predestine the failure of most attempts for active immunotherapy. Tumor immune suppression necessitates adhering to the adjuvant mode of immunotherapy, i.e. after the removal of large tumor masses. Understanding immune tolerance as active, threshold dependent and redundant processes helps to rationalize the reshaping and repair, rather than breaking, of tolerance as a tumor immunotherapy objective. Instead of true vaccines, the emerging concept is rather of immunomodulators that target the interface of innate and adaptive immunity.