New study suggests cancer spreads more rapidly depending on time of day

INDIANAPOLIS (WISH) – According to a new study, breast cancer is more likely to metastasize while patients are asleep. 

A study by Switzerland scientists included 30 women and a group of mice. They took routine biopsies several times over 24-hours. They found breast cancer tumors generate more cancerous cells when the patients were sleeping compared to when they were awake. The circulating cancer cells also divided more rapidly at night. 

“Our research shows that the escape of circulating cancer cells from the original tumor is controlled by hormones such as melatonin, which determine our rhythms of day and night. These findings may indicate the need for healthcare professionals to systematically record the time at which they perform biopsies” study author, Dr. Nicola Aceto, said in a news release

The authors plan to investigate if other cancers behave similarly to breast cancer. They also say this was not the original intent of their study, but a surprising and valuable finding.