In a new study, researchers found exposure to dim light at night may contribute to the spread of breast cancer to the bones.
The study finding provides new information that may help with the prevention and treatment of breast cancer.
The research was conducted by a team from Tulane University School of Medicine in New Orleans, La.
Exposure to dim light at night is very common in modern lifestyle.
Previous research has shown that the light could disturb sleep and disrupt the body clock.
This can lead to many health problems, including sleep loss, type 2 diabetes, high blood pressure, and heart disease.
However, no study has linked the nighttime dim light with the formation of bone metastatic breast cancer.
Research showed that more than 150,000 U.S. women had breast cancer in 2017 that spread outside the breast.
When breast cancer spreads, it often goes to the bones and can cause severe pain and fragile bones.
In the study, the researchers tested bone metastatic breast cancer in mice.
They injected estrogen receptor-positive human breast cancer cells into the tibia, or shinbone, of female mice.
The mice used in this study produce a strong nighttime circadian melatonin signal.
This nighttime melatonin signal could produce strong anti-cancer effects and help with sleep.
After that, all mice were kept in the light for 12 hours each day.
One group of three mice was in the dark the other 12 hours. This helped them produce high levels of endogenous melatonin.
The second group spent 12 hours in light followed by 12 hours in dim light at night. This suppresses their nocturnal melatonin production.
The dim light was less than a night-light or a display light from a cell phone.
Then the team took x-ray images of all mice.
They found that mice exposed to a light/dim light cycle had much larger tumors and higher bone damage compared with mice in a standard light/dark cycle.
The finding shows that circadian melatonin could help suppress bone-metastatic breast tumor growth and that dig light could disrupt the effect.
The team suggests their finding is important because many breast cancer patients are likely exposed to light at night due to lack of sleep and stress from cancer.
It is important for them to reduce dim light exposure and have healthy sleep habits. This can protect their health and improve their quality of life.
The team also hopes their finding can help develop a new treatment to inhibit or suppress the progression of breast cancer metastases to bone.
One author of the study is Muralidharan Anbalagan, Ph.D., an assistant professor.
The study was presented at ENDO 2019, the Endocrine Society’s annual meeting in New Orleans, La.
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