Some Cancer Cells Move, Jump Into Blood When People Sleep: Study

New Delhi: Despite being curable to some extent, cancer still remains one of the deadliest diseases, especially when the tumourous cells jump into the blood and infect another organ. A new study has now revealed that these tumourous cells in people with breast cancer jump into the blood when people are sleeping.

When tumorous cells that originated in one part of the body jump into another via blood, it is metastatic cancer, also called stage IV cancer. According to the National Cancer Institute, these cells have features like that of primary cancer and not like the cells in the place where the metastatic cancer is found. This is how doctors can tell that it is Metastatic cancer that has spread from another part of the body.

The study published in the journal Nature, states that dynamics that dictate the generation and dissemination of circulating tumour cells are largely uncharacterised, and it is often assumed that they are constantly shed from growing tumours or are shed as a consequence of mechanical insults.

The findings could enhance treatment strategies and tracking of the progression of these diseases. Led by researchers from the Swiss Federal Institute of Technology and the University of Basel, the team has revealed that these cells wake up when the patient is sleeping.

Researchers collected blood samples from 30 women hospitalised with breast cancer once during the day and once at night. They found that most of these cells appeared in the portion collected in the morning hours when the patients were still resting.

“I was surprised because the dogma is that tumours send out circulating cells all the time. But the data was very clear. So, soon after being surprised, we started being very excited,” Nicola Aceto, co-author of the paper told Nature.

To confirm the theory, researchers grafted breast cancer tumours into mice and tested the animals’ CTC levels throughout the day. Since mice have an inverted circadian rhythm to humans and are active during the night and sleep during the day, the tumour levels peaked during the day when the animal was resting.

Researchers, however, clarify that sleep is not the enemy and that the study does not mean people should avoid sleeping. Aceto told Nature that breast cancer cells in humans are more active at night and need deeper study. However, it could also be hormones that are used to signal that it’s time to wake up or go to bed that could have a big stake.

The team is now looking to further research in order to better understand the unique movement pattern of these cancerous cells to design better treatment strategies.