Cancer is a complex disease characterized by uncontrolled cell growth and proliferation.

While various factors contribute to the development and progression of cancer, emerging research has highlighted the critical role of circadian rhythms in cancer biology. Circadian rhythms are the 24-hour cycles that regulate numerous physiological processes in our bodies, including the sleep-wake cycle, hormone production, and metabolism.

Disruption of circadian rhythms, often caused by inadequate sleep, irregular work schedules, or frequent travel across time zones, has been associated with a higher risk of various health issues, including cancer.

This article provides a comprehensive overview of the relationship between circadian rhythms and cancer, delving into the mechanisms underlying this connection and exploring potential therapeutic interventions.

What are Circadian Rhythms?

Circadian rhythms are endogenous biological cycles that persist in the absence of external cues, such as light or temperature.

These rhythms are driven by the body’s master clock, a cluster of cells located in the suprachiasmatic nucleus (SCN) of the brain’s hypothalamus. The SCN interacts with other regions of the brain and aligns our internal clock with environmental cues, primarily the light-dark cycle.

Through a complex network of molecular interactions, the master clock regulates the expression of clock genes, which control the production of specific proteins.

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These proteins, in turn, regulate various cellular processes and prepare our body for different phases of the day. Hormone release, metabolism, cell division, and DNA repair are just a few examples of processes influenced by circadian rhythms.

The Influence of Circadian Rhythms on Cancer

Mounting evidence suggests that disruption of circadian rhythms can contribute to cancer development, progression, and treatment outcomes.

Irregular sleep patterns, night-shift work, and jet lag are known factors that disrupt our natural circadian rhythms, leading to what is known as circadian disruption.

Studies have shown a link between circadian disruption and an increased risk of developing various types of cancer, including breast, prostate, colorectal, and lung cancer.

Disrupted sleep-wake cycles have been associated with alterations in hormone levels, including melatonin, which plays a crucial role in regulating the sleep-wake cycle and has demonstrated anti-cancer properties.

Disruption of circadian rhythms has also been shown to impact tumor growth and progression. Cancer cells have their own internal clocks, which can be influenced by the surrounding circadian environment.

Certain genes involved in cell division and DNA repair exhibit rhythmic expression, making them sensitive to circadian perturbations. Moreover, disrupte.