Sleep Duration and Cancer Risk Associations

Emerging evidence indicates that both insufficient and excessive sleep can influence cancer risk through a convergence of epidemiological patterns and biological mechanisms. Observational studies have linked short sleep duration with elevated risks of site-specific malignancies such as colorectal and gastric cancer, while long sleep has been associated with hormonal and inflammatory alterations that may predispose to tumour development. Disruption of circadian rhythms appears to impair melatonin secretion and immune surveillance, promote oxidative stress and DNA damage, and modulate hormone levels. These pathways interact in a complex network, implicating sleep as a modifiable factor in oncogenesis and highlighting the potential for preventive strategies centred on sleep hygiene and chronobiological alignment.

Research from Nature Portfolio

In a large case–control analysis of colorectal and gastric cancer, self-reported sleep duration and daytime napping were examined across multiple Spanish hospital sites. Compared with seven hours of sleep, both short (≤5 hours) and long (≥9 hours) nocturnal sleep were associated with higher odds of gastric cancer, while extended sleep was linked to increased odds of colorectal cancer. Frequent and prolonged daytime naps further elevated cancer odds, with the strongest effects observed among individuals with a history of night-shift work. These findings emphasise the combined role of nocturnal and diurnal sleep patterns in gastrointestinal cancer risk.

Sleep Duration and Cancer Risk Associations publication trend

The graph below shows the total number of articles in sleep duration and cancer risk associations across all publications each year (not limited to Nature Index journals).

Technical terms

Circadian rhythm: Endogenous 24-hour cycle regulating physiological and behavioural processes, including sleep–wake timing and hormone secretion.

Exosome: Nano-sized extracellular vesicle released by cells, carrying proteins and nucleic acids that mediate intercellular communication.

M2 macrophage polarization: Phenotypic shift of macrophages towards an anti-inflammatory, tissue-remodelling state that can promote tumour progression.

Hazard ratio: Measure of how often a particular event occurs in one group compared to another over time in cohort studies.

Oxidative stress: Imbalance between reactive oxygen species production and antioxidant defences, leading to cellular damage and DNA mutations.

References

1. Sleep duration and napping in relation to colorectal and gastric cancer in the MCC-Spain study. Scientific Reports (2021).
2. Sleep and liver function biomarkers in relation to risk of incident liver cancer: a nationwide prospective cohort study. BMC Medicine (2024).
3. The Triad of Sleep, Immunity, and Cancer: A Mediating Perspective. Cells (2024).
4. GABA induced by sleep deprivation promotes the proliferation and migration of colon tumors through miR-223-3p endogenous pathway and exosome pathway. Journal of Experimental & Clinical Cancer Research (2023).