Personalized cancer therapy has come to the fore, as it holds promise for better outcomes. While genetic profiling has a growing impact on precision medicine, utilizing genomic data for clinical decision-making in a timely manner is still complex, and in many cases has low predictive value. Animal models are time consuming and expensive, and are sometimes unsuccessful when translated to human subjects. To overcome these obstacles, we have optimized an ex-vivo organ culture (EVOC) system. In this method, samples of freshly-removed tumors are treated for up to seven days and the response assessed by various methods. This method is very flexible and can be adapted to various models and to answer a multitude of clinical and biological questions. Patient specific drug treatments can be tested to help direct successful anti-cancer therapy. Also novel hypotheses can be tested directly on live human tumor tissue thereby accelerating the drug discovery pipeline to expedite clinical drug trials.