Cancer cells attack you faster while you are sleeping: Study explains
Premium- Long-term studies show that people who work odd hours are more prone to breast cancer.
Cancer cells are more likely to attack you during the night than during the day, a new study has found. Explaining the pattern, experts said that cells are deadliest when they are in the bloodstream travelling to a new location - this process is called metastasis. Now, for breast cancer patients, these rogue cells are more likely to jump into the blood at night than during the day.
The relationship between body’s circadian rhythm and cancer cells has been a topic of discussion for years. 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, as published in the scientific journal Nature.
People who work odd hours are more prone to breast cancer
International Agency for Research on Cancer listed disrupted circadian rhythm as a “probable" carcinogen in 2007 based on long-term studies that showed that people who work odd hours are more prone to breast cancer.
Taking a note of the same study, Aceto elaborated that a person’s circadian clock is controlled by various genes and specific molecules influence multiple functions in your body including metabolism and sleep. “Most researchers, however, had initially thought that cancer cells were so screwed up, so highly mutated that they wouldn’t conform to such a schedule," Aceto says.
For this research, Aceto and his team collected blood from 30 women hospitalized with breast cancer, once at 4 a.m. and again at 10 a.m.
The researchers found that the bulk of the CTCs they found in the blood samples — almost 80% — appeared in the portion collected at 4 a.m., when the patients were still resting. At first, “I was surprised because the dogma is that tumours send out circulating cells all the time", Aceto says. “But the data were very clear. So, soon after being surprised, we started being very excited."
It’s a “step forward" in understanding metastasis, Aceto says. “And steps forward are a good thing for patients in the long-term".
Sleep is not the enemy
However, Qing-Jun Meng, a chronobiologist at the University of Manchester, UK, pointed out that sleep is not the enemy.
Some studies have shown that people who have cancer and who commonly get less than seven hours of sleep per night are at higher risk of death, and messing with circadian rhythms in mice can make cancer move faster. The findings aren’t an indication that “you don’t need sleep, or that you need less sleep", he says. “It simply means these cells prefer a specific phase of the 24-hour cycle to go into the bloodstream."