CTCs for Biomarker and Companion Diagnostic Development

Abstract

Circulating tumor cells (CTCs) were first recognized in the blood of cancer patients by Thomas Ashworth in 1869. Recent advances have propelled CTCs to center stage in diagnostic and translational research, largely owing to advances in isolation technology and increasing sensitivity of the various genomic, transcriptomic, and proteomic platforms. As we enter the era of personalized medicine, it is foreseeable that CTCs will become an integral component of clinical practice to not only understand disease evolution but also match patients with appropriate therapeutics. The current field is inundated with an enormous amount of data studying diverse aspects of CTC biology. In this chapter, we focus on recent developments in the incorporation of CTCs in oncology clinical studies that suggest promising utility for CTCs as pharmacodynamic and predictive biomarkers that can fundamentally aid decision making in clinical trials. In light of the complexity inherent in codeveloping in vitro diagnostic assays with therapeutic agents, we highlight key challenges and suggest solutions to enable the ultimate goal of developing CTCs as companion diagnostic assays for targeted oncology therapeutics.