Australian study on mice reveals stress can cause cancer to spread faster through the body

The body’s lymphatic system may allow breast cancer cells to spread faster if a sufferer is stressed. New Australian research has shown chronic stress accelerates the spread of cancer in mice. And as animal understanding may eventually lead to a better understanding of cancer in humans, it is important to take this mice study seriously. Moreover, the scientists have also found a way to prevent it from happening, also in mice.

Even though the medical world has long debated on how stress may affect a patient’s prognosis, and although it has never really been proven that stress causes cancer, it may play an important role in its spread. Cancer biologist Erica Sloan led a Monash University research team to study how stress drives metastasis in mice with breast cancer.

Sloan revealed that even though it is already known that cancer can spread through the body’s lymphatic system, stress transformes the network into a kind of super highway that allows the cancer cells to spread faster. The researchers noticed “six times more spread of cancer in stressed mice compared to control mice.”

“Stress sends a signal into the cancer that allows tumour cells to escape from the cancer and spread through the body. The stress is sort of acting like a fertiliser and helping the tumour cell take hold and colonise those other organs,” Sloan told the ABC.

It is known that stress increases in a patient once he/she is diagnosed with cancer. However, Sloan and the research team also found a class of medication that prevented stress from facilitating the cancer’s spread. This class of medication is currently used for cardiac arrhythmia and for high blood pressure.

The beta blockers in these medicines prevent the stress response by competing with the adrenaline to limit heart rate and blood pressure increase. When the mice with cancer were given these beta blockers, it totally negated the stress response. The stress couldn’t transform the lymphatic system that could facilitate the cancer’s spread.

A cancer-specific beta blocker may be developed to target tumours and not the heart, depending on the success of anaesthetist Dr. Jonathan Hiller’s human pilot trial at the Peter MacCallum Cancer Centre in Melbourne. Blood samples before and after surgery are being recorded from patients who have either been given a placebo or the beta blocker Propanolol.

“We've chosen the peri-operative period because, as an anaesthetist, we often see women have a state of increased stress and anxiety at the time of surgery, and the build-up to surgery following diagnosis can be incredibly anxiety provoking,” Hiller told Catalyst.