Despite substantial advancements in cancer management, a considerable proportion of patients cannot yet be cured. Strategies to address this open medical need are actively pursued and include two main approaches: 1) optimizing diagnostic protocols to detect tumors at early stages, and 2) designing personalized therapies to increase efficiency and selectivity of clinical interventions. Our recent work has been directed to a rationally-designed implementation of both approaches. Particularly, we have contributed to the development of nanomedicines that can be targeted to diseased tissues for theranostic purposes in preclinical models of human cancers. Such modular nanoscale systems proved to be versatile platforms to combine imaging and drug delivery for applications in the oncological field and could be a basis for future improvements.