Researchers make ‘striking’ discovery that breast cancer cells are more likely to jump into the blood when people are resting.
Credit: Science Photo Library
The research community has been discussing for decades how the body’s circadian rhythm influences cancer. With this study, it has become clear that “tumours wake up when patients are sleeping”, says co-author Nicola Aceto, a cancer biologist at the Swiss Federal Institute of Technology in Zurich, Switzerland. It’s a “step forward” in understanding metastasis, he says. “And steps forward are a good thing for patients in the long-term”.
The next step for the researchers was to confirm whether this was true beyond these few people. To do this, the team grafted breast cancer tumours into mice and tested the animals’ CTC levels throughout the day. Compared with humans, mice have an inverted circadian rhythm, meaning that they are most active at night and tend to rest during the day.