Targeting chromosomal instability in patients with cancer

Chromosomal instability (CIN) is a hallmark of cancer and a driver of metastatic dissemination, therapeutic resistance, and immune evasion. CIN is present in 60–80% of human cancers and poses a formidable therapeutic challenge as evidenced by the lack of clinically approved drugs that directly target CIN. This limitation in part reflects a lack of well-defined druggable targets as well as a dearth of tractable biomarkers enabling direct assessment and quantification of CIN in patients with cancer. Over the past decade, however, our understanding of the cellular mechanisms and consequences of CIN has greatly expanded, revealing novel therapeutic strategies for the treatment of chromosomally unstable tumours as well as new methods of assessing the dynamic nature of chromosome segregation errors that define CIN. In this Review, we describe advances that have shaped our understanding of CIN from a translational perspective, highlighting both challenges and opportunities in the development of therapeutic interventions for patients with chromosomally unstable cancers. Chromosomal instability (CIN) is a dynamic phenotype characterized by changes in chromosome number and structure and is a hallmark of clinically aggressive malignancies. Nonetheless, the ability of cancer cells to tolerate CIN creates several potential therapeutic vulnerabilities. In this Review, the authors describe the development of CIN and how this phenotype promotes carcinogenesis and tumour progression as well as describing the various attempts to develop targeted therapies based on the specific vulnerabilities of these tumours.