Seasonal Changes in Melatonin Levels in Women with Breast Cancer
Author Information
Author(s): I.M. Holdaway, B.H. Mason, E.E. Gibbs, C. Rajasoorya, K.D. Hopkins
Primary Institution: Auckland Hospital, Auckland, New Zealand
Hypothesis
The study investigates whether seasonal variations in serum melatonin levels affect tumor growth in women with previous breast cancer.
Conclusion
Women with previous breast cancer show significant seasonal differences in melatonin production, particularly a reduction in winter compared to summer.
Supporting Evidence
- Melatonin secretion was significantly lower in winter for women with previous breast cancer compared to controls.
- The amplitude of the nocturnal melatonin pulse was significantly greater in summer than in winter for winter detectors of breast cancer.
- The acrophase of the nocturnal melatonin pulse was significantly advanced in women with previous breast cancer.
Takeaway
The study found that women who had breast cancer produced less melatonin in winter than in summer, which might affect their cancer growth.
Methodology
Serum melatonin concentrations were measured every 2 hours for 24 hours at the summer and winter solstice in women with previous breast cancer and controls.
Potential Biases
The control group was significantly younger than the breast cancer group, which may influence melatonin levels.
Limitations
The study had a small sample size and did not control for menstrual cycle phases during sampling.
Participant Demographics
20 pre-menopausal women with previous breast cancer and 9 control women.
Statistical Information
P-Value
P<0.002 for amplitude and P<0.005 for AUC
Statistical Significance
p<0.01
Want to read the original?
Access the complete publication on the publisher's website