Animal Models Systems of Cancer for Preclinical Trials

Over the recent preceding few decades, cancer has existed as the second leading cause of death after cardiovascular diseases globally. Therefore, effective therapies are required to enhance the survival rate and lead a quality life for cancer patients. Preclinical trials are a prerequisite for the development of effective cancer therapeutics. However, direct experimentation on human subjects cannot be undertaken due to several ethical, safety, and practical issues. Hence, preclinical animal model systems have become an indispensable part, since these allow to decipher the highly complex cascades responsible for human cancer, and may help in the prediction of safety and efficacy of anticancer drug or therapy for successful translation into clinical trials. Mouse models mostly have utility in preclinical trials. While the other systems utilized include zebrafish, Drosophila, and C. elegans models. These alternative preclinical models give complimentary information for the development of cancer therapeutics. Nevertheless, companion preclinical models like dog and swine are underexploited though these can fasten to fill the gap information required between preclinical and clinical trials of cancer. The aim is to mimic this deadly and complicated disease in animal models and reflect the situation in humans for effective therapeutics. This chapter throws light on various animal models used in preclinical trials of cancer, their significance, and challenges associated with it.