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in collaboration with
Dr Christophe de Jaeger (Longevity and geriatrics)
Medical validation:
June 27, 2022
Could cancer choose its time to spread? Yes, according to researchers at the Swiss Federal Institute of Technology in Zurich. A discovery that could improve treatments.
Researchers from the Swiss Federal Institute of Technology Zurich (ETHZ) have made an astonishing discovery about cancer cells. According to them, the circulating tumor cells produced by breast cancer tumors multiply mainly at night. An astonishing advance, which could make it possible to adapt the treatment of patients.
Tumor generates more circulating cells overnight
This observation, reported by the team of biotechnologist Nicola Aceto, was published on Wednesday June 22 in the medical journal Nature.
“When the person sleeps, the tumor wakes up“, summarized the professor of molecular oncology.
To confirm this hypothesis, Nicola Aceto and his team observed the metastases of 30 patients suffering from breast cancer, including 9 with metastatic disease. To do this, they took blood samples between 4 a.m. and 10 a.m.
The scientists then realized that 78.3% of circulating tumor cells (cells that come from the primary tumor and circulate in the blood to colonize new tissues) were detected in the nocturnal samples.
Cells that left the tumor during the sleep phase also divided faster than those that left the tumor during the day.
Surprising results, confirmed shortly afterwards on mice: 87 to 99% of the circulating tumor cells of rodents were detected in the night tests.
“This study opens interesting therapeutic perspectives in terms of time adaptation. Doing chemotherapy at 4:00 a.m. seems to be an idea to study and confirm. It would also be relevant to know if this nocturnal multiplication of cancer cells applies to other cancers”says Dr. Christophe de Jaeger, specialist in aging.
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How to explain such a difference ? A hormonal track is put forward by the researchers.
“Our research shows that the escape of circulating cancer cells from the original tumor is controlled by hormones such as melatonin, which determine our day and night rhythms.“, emphasizes Zoi Diamantopoulou, lead author of the study and postdoctoral researcher at ETH Zurich.
However, “this renewed nocturnal activity of tumor cells in breast cancer is probably due to a combination of many factors that remain to be clarified“, specifies Nicola Aceto.
Indeed, the simple “night” factor would hardly explain this change in cellular activity, according to Dr. Jaeger.
“What worries me is the hormonal aspect. It is known that melatonin slows the development of tumor cells. But we also know that as we age, the level of melatonin decreases and the number of breast cancers increases. It could therefore be that the hormones – at night – are actually disturbed by other factors: such as stress, sleep disturbances… It has also been proven that the frequency of breast cancer in night workers is more important. It is therefore a track that deserves to be dug“, notes Dr. Jaeger.
If this discovery is confirmed, it could eventually allow doctors to optimize cancer treatments for patients.
But before, “Further studies will first be needed to unravel the complex links between human circadian rhythms and cancers.”, conclude the researchers.