Cancer remains a leading cause of death in the world. To overcome this problem, it is necessary to develop new analysis tools, in complementarity to existing ones, to enable the early diagnostic of the diseases, personalized treatment, and further fundamental cancer mechanisms understanding. In this context, microwave-based and millimeter-wave-based dielectric spectroscopy performed at the cellular and molecular levels is progressively emerging, as it permits the non-invasive and real-time probing of cells in their culture biological medium. The recent advances of this topic are given in this paper with a specific highlight of its various assets.