Significance Chemotherapy has been proven in clinical studies to improve overall survival significantly. Unfortunately, there is a significant degree of heterogeneity in tumor chemosensitivity, often resulting in unnecessary treatment and needless exposure to toxic side-effects. A platform is needed that can identify preemptively which patients will or will not benefit from treatment. Tumor organoids, 3D cultures of cancer cells, present such an individualized platform. In this study we demonstrate that organoid cultures can be established from metastatic biopsy specimens with a high success rate and genetically represent the metastasis they were derived from. These data support the translation of this innovative technology to the clinic as an ex vivo screening platform for tailoring treatment.