Do sex hormones confound or mediate the effect of chronotype on breast and prostate cancer? A Mendelian randomization study
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View abstract on PubMed
Summary
This summary is machine-generated.Morning preference chronotype shows a protective effect against breast and prostate cancer. While sex hormones like testosterone are linked to cancer risk, their role as mediators in this relationship requires further investigation.
Area Of Science
- Chronobiology
- Endocrinology
- Cancer Epidemiology
Background
- Morning-preference chronotype is associated with reduced breast and prostate cancer risk.
- Sex hormones, including testosterone and estradiol, are implicated in both chronotype and cancer development.
- The potential confounding or mediating role of sex hormones in the chronotype-cancer relationship remains unclear.
Purpose Of The Study
- To investigate the causal relationships between chronotype, sex hormones, and breast/prostate cancer using Mendelian Randomization (MR).
- To assess whether sex hormones confound or mediate the protective effect of morning preference on cancer risk.
Main Methods
- Utilized genetic variants associated with chronotype and sex hormones (total testosterone, bioavailable testosterone, SHBG, estradiol) from large genome-wide association studies.
- Employed univariable, bidirectional, and multivariable MR analyses to examine causal pathways.
- Investigated relationships with breast cancer (133,384 cases/113,789 controls) and prostate cancer (79,148 cases/61,106 controls).
Main Results
- In females, morning preference was linked to reduced breast cancer risk. Higher bioavailable and total testosterone levels increased breast cancer risk.
- In males, morning preference was associated with reduced prostate cancer risk, while higher bioavailable testosterone increased prostate cancer risk.
- Bidirectional causal effects were observed between morning preference and testosterone in females, but not in males. Evidence for testosterone mediating the chronotype-cancer link was inconsistent.
Conclusions
- Morning preference chronotype demonstrates a protective effect against both breast and prostate cancer.
- Testosterone levels are causally linked to both chronotype and cancer risk, but their role as a mediator is not consistently supported.
- Further research is needed to identify other potentially modifiable factors that link chronotype to cancer risk.
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