Circadian clock in thyroid cancer: Effects and mechanisms.

The circadian clock, an endogenous timekeeping system governed by core genes such as BMAL1, CLOCK, PER, and CRY, regulates physiological processes critical to thyroid function. Disruption of circadian rhythms (resulting, for example, from shift work and/or exposure to artificial light at night) has emerged as a significant risk factor for thyroid carcinogenesis. This review elucidates the dual role of circadian rhythms in maintaining thyroid homeostasis and their mechanistic contributions to cancer initiation, progression, and therapy resistance. We highlight molecular pathways linking clock dysregulation to oncogenic signaling, immune evasion, and metabolic reprogramming, while proposing chronotherapy as a novel precision oncology strategy.