The present invention relates a bioprinted three-dimensional tumor model which is able to reproduce the cellular heterogeneity, the spatial architecture, and the tissue-specific ECM of the tumor microenvironment. In addition, the invention refers to a process for preparing such three-dimensional tumor model, to methods for testing anticancer drugs as well as to the use of the tumor model in developing personalized medicine and developing new therapies based on the understanding of the in vitro tumor progression.