Polytherapy and Targeted Cancer Drug Resistance.

A current challenge in cancer treatment is drug resistance. Even the most effective therapies often fail to produce a complete and durable tumor response and ultimately give rise to therapy resistance and tumor relapse. However, how resistance arises in cancer remains incompletely understood. While drug resistance in cancer is thought to be driven by irreversible genetic mutations, emerging evidence also implicates reversible proteomic and epigenetic mechanisms in the development of drug resistance. Tumor microenvironment-mediated mechanisms and tumor heterogeneity can significantly contribute to cancer treatment resistance. Here, we discuss the diverse and dynamic strategies that cancers use to evade drug response, the promise of upfront combination and intermittent therapies and therapy switching in forestalling resistance, and epigenetic reprogramming to combat resistance.