This is a discovery that could change the way certain cancers are treated: malignant tumors generate more circulating cells during the night.
Cancer cells would develop more during the night, this is revealed by a Swiss study by the Swiss Federal Institute of Technology Zurich (ETHZ)) conducted on breast cancer and published on Wednesday June 22 in the medical journal Nature. On the strength of this observation, the researchers are considering the possibility of adapting the treatments of the patients.
Spread of cancer cells promoted during sleep
“When the person sleeps, the tumor wakes up”, said Nicola Aceto, professor of molecular oncology at ETH Zurich, who led the study. During this study, conducted with 30 patients with breast cancer, the professor and his team noticed that the tumor was generating more circulating cells (cells that come from the primary tumor and that circulate in the blood to colonize new tissues) when the body was asleep. By taking blood samples between 4 a.m. and 10 a.m., they found that 78.3% of circulating tumor cells came from night samples. They also found that cells that left the tumor during the sleep phase also divided faster than those that left the tumor during the day.
These astonishing results were then confirmed by similar tests carried out on mice. 87-99% of rodent circulating tumor cells were detected during overnight testing.
Cancer cells spread aggressively during sleep https://t.co/gMSxLOTFkJ
— nature (@Nature) June 22, 2022
The role of hormones
This 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”underlines Zoi Diamantopoulou, lead author of the study and postdoctoral researcher at ETH Zurich.
If this discovery is confirmed, it could in the future allow doctors to optimize cancer treatments for patients. Whatever, “Further studies will first be needed to unravel the complex links between human circadian rhythms and cancers”conclude the researchers.
Fight against the formation of metastases
A pioneer in research on the development of metastases, Nicola Aceto has studied for several years how cells contribute to the spread of cancer via metastases, thus seeking effective therapies to stop this process. It should be noted, in particular, that for most deaths due to cancer, patients succumb not because of the tumor of the primary cancer but of its malignant proliferations. Metastases are responsible for nine out of ten cancer deaths. This study therefore opens interesting therapeutic perspectives in terms of time adaptation. The researchers’ next step will be to determine how these findings can be incorporated into existing cancer treatments to optimize therapy outcomes.
Although the chances of recovery increase with new treatments, “Breast cancer ranks first among incident cancers in women, clearly ahead of colon-rectum cancer and lung cancer, emphasizes the National Cancer Institute (Inca), before adding that “it is also the one that causes the greatest number of deaths in women, with 14% of female cancer deaths in 2018”.