CRISPR in clinical oncology: translational advances from molecular diagnostics to therapeutics

Cancer care is increasingly driven by molecular classification, yet many key oncogenic drivers remain undruggable, and intrinsic or acquired resistance to treatment frequently limits durable clinical benefit. CRISPR-Cas technologies provide a modular, programmable platform to interrogate and directly manipulate cancer biology via sequence-specific targeting of DNA or RNA and have advanced from experimental tools to the early stages of clinical translation. In this Review, we outline how CRISPR-enabled functional genomics approaches can reveal unexpected cancer dependencies and resistance mechanisms. We discuss emerging applications of CRISPR-based diagnostics in oncology that convert precise nucleic acid sequence recognition into rapid mutation detection. We also discuss applications of CRISPR in therapeutic strategies ranging from ex vivo immune cell engineering to nascent in vivo interventions that directly target tumour-related sequences such as fusion junctions or single-nucleotide variants. Finally, we highlight technological and regulatory challenges, including effective delivery of the editing machinery to cells in vivo, safety and platform-level regulatory frameworks, that will determine the clinical utility of CRISPR-based diagnostics and therapies in oncology.