The research, published in Nature, specifically showed that circulating cancer cells that later form metastases mainly arise during the sleep phase.
The discovery was revealed by an analysis of the migration of human tumour cells in the bloodstream.
Nicola Aceto, Professor of Molecular Oncology at the ETH Zurich, summarised the findings by saying: “When the affected person is asleep, the tumour awakens.”
Zoi Diamantopoulou, the study’s lead author and a postdoctoral researcher at ETH Zurich, added: “Our research shows that the escape of circulating cancer cells from the original tumour is controlled by hormones such as melatonin, which determines our rhythms of day and night.