PDO have been shown to efficiently recapitulate ex-vivo the in vivo response to hormonal treatment of BC patients. These observations point to PDO as potential valuable tools for a rapid, personalized prospective evaluation of patient-specific chemo-sensitivity. Moreover, PDO can represent a valuable ex-vivo platform for screening new treatments, or combination of current treatments, in a medium-to-high-throughput fashion. Thus, development of a stable collection of PDO representing the heterogeneity of BC subtypes, including the evolution of recurrent disease, represents an extremely useful resource for both prospective and retrospective studies aimed at understanding the molecular phenotype associated with chemoresistance.
