MELBOURNE, June 28 (Xinhua) -- A team of Melbourne researchers have discovered that stress leads to cancer spreading more rapidly throughout the body.
A Monash University research team, led by cancer biologist Dr Erica Sloan, conducted a study on mice with breast cancer and found that increased stress levels drove metastasis, the spread of cancer cells to new areas of the body.
There has long been a medical debate around the role of stress in a patient's cancer diagnosis. While stress has never been proven to cause the cancer, these Australian researchers believe it might have played a significant role in exacerbating the cancer.
Sloan said her team discovered how increased stress transformed the body's lymphatic system into a 'super highway' for breast cancer cells to spread at much faster speeds.
"Stress sends a signal into the cancer that allows tumour cells to escape from the cancer and spread through the body," Sloan told the Australian Broadcasting Corporation (ABC) on Tuesday.
"The stress is sort of acting like a fertilizer and helping the tumour cell take hold and colonies those other organs."
The study used mice with cancer and gave them limited movement in order to mirror the physiological and emotional effects of stressed humans.
Dr Caroline Le, another of the researchers of the study, said they tracked the effect that stress had on the cancer-affected mice.
"You see six times more spread of cancer in stressed mice compared to control mice," Le said.
The Melbourne researchers found an old class of medication which could prevent the effect of stress in cancer, at least in mice.
The medication is currently used for people with high blood pressure and cardiac arrhythmia, a condition where the heartbeat is irregular.
The medication contains beta blockers, which help to reduce a patient's blood pressure and adrenaline, therefore limiting the heart rate and preventing the response from stress.
When the mice with cancer were given the beta blockers, the stress was neutralized. The stress didn't affect the lymphatic system, which initially led to the rapid cancer spread.
There is an exploratory human trial currently being conducted at Melbourne's Peter MacCallum Cancer Centre.
Led by anaesthetist Dr Jonathon Hiller, the trial is focused on anxiety in female surgical patients who have recently been diagnosed with breast cancer.
"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 ABC television on Tuesday.
These patients have been given beta blocker medication and their stress levels, before and after surgery, are being recorded via blood samples.