Cancer-on-chip technology: current applications in major cancer types, challenges and future prospects

Conventional 2D cell cultures are widely used for the development of new anticancer drugs. However, their relevance as in vitro models is increasingly questioned as they are considered too simplistic compared to complex, three-dimensional in vivo tumors. Moreover, animal experiments are not only costly and time-consuming, but also raise ethical issues and their use for some applications has been restricted. Therefore, it becomes crucial to develop new experimental models that better capture the complexity and dynamic aspects of in vivo tumors. New approaches based on microfluidic technology are promising. This technology has indeed been used to create microphysiological systems called 'organ-on-chip' which simulate key structural and functional features of human tissues and organs. These devices have further been adapted to create cancer models giving rise to the 'cancer-on-chip' (COC) concept. In this review, we will discuss the main COC models described so far for major cancer types including lung, prostate, breast, colorectal, pancreatic, and ovarian cancers. Then, we will highlight the challenges that this technology is facing and the possible research perspectives that can arise from them.