Hurdles in Cancer Immunotherapy

Recent advances in basic immunology have revealed impressive breakthroughs in the field of cancer immunotherapy, inspiring oncologists to translate this knowledge to the treatment of different types of cancers. However, several hurdles limit the efficiency of immunotherapy in increasing the overall survival of patients (Fig. 31.1). These hurdles rank from practical and economic issues such as feasibility and cost-effectiveness of immunotherapy and design of the clinical trials to the several immunological hurdles. In the immunological hurdles, tumor cells possess several mechanisms to evade the immune system response. A combination of factors such as the production of inhibitory cytokines and soluble factors such as the expression of inhibitory markers and conversion of cellular infiltrates into the tolerizing cells contribute to evasion of the immune system. Moreover, some tumor cells acquire apoptosis resistance through different strategies, and some cause the immune system to autoreact to host tissue. All these mechanisms inhibit tumor regression and the effectiveness of immunotherapy. Moreover, immunotherapy-related toxicities have proven to be a major issue in cancer immunotherapies, which required timely and properly management. Therefore, efforts for minimizing the side effects in parallel to maximizing the efficiency of immunotherapies are still warranted. In this chapter, we discuss the potential hurdles that confront cancer immunotherapy and the potential strategies to overcome these challenges and achieve a successful immune response against tumor.