While the scientific community believed that breast tumors continuously release metastatic cells, a team of Swiss researchers discovered that cancer cells that circulate and then metastasize occur primarily during sleep.
This is the main conclusion of a study using a mouse model with 30 patients and is currently published in scientific journals. Nature It is led by researchers at the Federal Institute of Technology (ETH) Zurich, the University of Basel Hospital, and the University of Basel (Switzerland).
According to the World Health Organization (WHO), breast cancer is one of the most common forms of cancer. About 2.3 million people worldwide suffer from this disease each year.
If the doctor detects breast cancer early, the patient usually responds well to the treatment applied. But if the cancer has already spread, things become much more difficult. Metastasis occurs when circulating cancer cells move away from the original tumor, travel through blood vessels, and form new tumors in other organs.
So far, studies conducted on breast cancer have paid less attention to how long the tumor releases metastatic cells, according to the director of the currently published study. This new study “has come to an astonishing conclusion.“: Circulating cancer cells that later form metastases occur primarily during the sleep phase.
A hormone regulated by circadian rhythm-controlled metastasis. “When the affected person is asleep, the tumor awakens,” summarizes research leader Nicola Aceto, a professor of molecular oncology at ETH Zurich.
During a study of 30 cancer patients and mice, researchers discovered that the tumor produces malignant cells that circulate when the body is asleep. Cells that leave the tumor overnight are also more likely to metastasize than cells that leave the tumor during the day because they divide more rapidly.
“Our study shows that the release of circulating cancer cells from the original tumor is regulated by hormones such as melatonin that determine daytime and nighttime rhythms,” also an ETH Zurich researcher. Zoi Diamantopoulou added.
In addition, this study shows that the time a tumor or blood sample is taken for diagnosis can influence the conclusions of oncologists. According to the Swiss Research Center, it was a coincidence that the researchers were first put on the right track.
Scientists were surprised that the levels of cancer cells in samples taken at different times of the day were very different. “These results may indicate that medical professionals need to systematically record the time it takes to perform a biopsy,” Aceto emphasized, “to allow the data to be actually compared. It helps to make it. “
The next step for researchers is to find out how these findings can be incorporated into existing cancer treatments to optimize treatment. Aceto wants to investigate whether different types of cancer work like breast cancer and whether existing treatments may be more successful if patients are treated at different times. I am.