Stress Causes Cancer to Spread Six Times Faster

Stress can be deadly, especially if you have cancer. Researchers at Australia's Monash Institute of Pharmaceutical Sciences found that chronic stress increases activity in the lymphatic system allowing cancer to spread six times faster.

The lymphatic system carries immune cells throughout the body to fight illness, but stress allows "cancer highways" to develop in the lymphatic system that helps cancer cells spread.

"We found that chronic stress signals the sympathetic nervous system (SNS) – better known as the 'fight-or-flight' response – to profoundly impact lymphatic function and the spread of cancer cells," said Caroline Le, Ph.D. 

Being diagnosed with cancer is stressful, and surgery, radiation, and chemotherapy treatments add to the load. The research points to controlling stress as being an important part of cancer treatment.

"These findings demonstrate an instrumental role for stress in controlling lymphatic function to impact health, and suggest that blocking the effects of stress to prevent cancer spread through lymphatic routes may provide a way to improve outcomes for patients with cancer," Le said.

Mice were used to track the spread of breast cancer.  Researchers tagged breast cancer cells with a fluorescent marker and used state-of-the-art imaging techniques to see tumor cells that had spread into lymphatic vessels.

The imaging showed that stress increases the number and size of lymphatic vessels in and around tumors, as well as increases the rate fluid flows through them. Both factors combine to increase the capacity of lymphatic "highways" to carry and spread tumor cells throughout the body.

"You see six times more spread of cancer in stressed mice compared to control mice," Lee told the Australian Broadcasting Company.

Importantly, the study also found that blocking neural signaling in patients, with drugs that are readily available and currently used to treat hypertension such as beta blockers, regulates the function of lymphatic vessels to prevent the spread of cancer cells.

Ultimately, the study may provide a way to improve outcomes for patients with cancer.