Three-dimensional in vitro Tumor Models as an Alternative for Animal Models in Preclinical Studies

Cancer is one of the leading causes of death world-wide. For drug screening and development, appropriate tumor models are needed that reflect the situation in the patient robustly and accurately. Next to the identification of new compounds, cancer research contributes to the understanding of complex tumor biology. This enables targeted and individualized drug development. For these different issues tailored tumor models are required. In this present work we illuminate important research approaches which use various kinds of tumor models. These include animal models, two-dimensionally cultured cancer cell lines and primary cells as well as newly developed more complex three-dimensional cell culture models. Their advantages and disadvantages are discussed and an insight into the actual options for drug testing and development is given. Furthermore, some more sophisticated technologies are presented such as tissue engineering and the use of special bioreactors which will gain importance in the future.