Rhythms of risk: the intersection of clocks, cancer, and chronotherapy

Circadian clocks govern daily rhythms in cellular and physiological processes, including cell cycle, DNA repair, metabolism, and immune function, that influence cancer development and treatment response. Disruption of circadian regulators either promotes or suppresses malignancy depending on tumor type and biological context. This duality likely reflects systemic rewiring of circadian physiology and direct interactions between clock components and oncogenic pathways. These insights hold clinical relevance for the field of chronotherapy, which seeks to enhance therapeutic efficacy and minimize toxicity by aligning drug administration with circadian rhythms or by targeting elements of the molecular clock. In this Review, we highlight the promise of integrating circadian biology into precision oncology and underscore the importance of cancer type-specific investigations to harness the full therapeutic potential of chronotherapy in cancer.