Chronic stress enhances cancer spreadMarch 2nd, 2016
Although stress can cause a number of physical health problems, there is scant evidence that it can cause cancer. However, NBCF-funded researcher Dr Erica Sloan from the Monash Institute of Pharmaceutical Sciences has discovered that stress can contribute to existing cancers spreading to other parts of the body, which significantly reduces survival outlook.
Understandably, people living with cancer may find the physical, emotional, and social effects of the disease stressful. Dr Sloan has found that stress acts as a ‘fertiliser’ for tumours, helping them spread through the body’s lymphatic system.
Dr Sloan said a link between chronic stress and cancer spread — not new cancers — has been shown in several studies, particularly in individuals with early stage disease, which highlights an opportunity to reduce both stress and the risk of cancer spread or secondary tumours.
“Not for a minute are we suggesting that someone who’s just been diagnosed with cancer should not be stressed, because that would have to be one of the most stressful situations,” she said.
“But rather, how we look after cancer patients, because this suggests that stress not only affects patient wellbeing but also gets into the body and affects how the tumour progresses.”
The research, published in Nature Communications, reports how exposure to chronic stress not only increases the number of lymphatic vessels draining from the tumour, but also increases flow in existing vessels.
The lymphatic system — a vital part of the immune system comprised of a network of tubes throughout the body that drain fluid from tissues back into the bloodstream — can also promote the spread of cancer, but whether this can be influenced by stress had been unclear up to now.
“That was one of the key findings of this study, because we can identify that stress hormones, such as adrenaline, are acting through particular receptors on cells, and that tells us what drugs we should use to block these pathways,” Dr Sloan said.
The research also showed that a well-known drug, propranolol (part of a group known as beta-blockers used to treat high blood pressure), may reduce the risk of the cancer spreading.
Because propranolol is already in widespread use, Dr Sloan and her colleagues were able to look at data from nearly 1,000 breast cancer patients in Italy which showed that those that taking beta-blockers showed far less evidence of tumour cells moving into the lymph nodes and then spreading to other organs, which has provided the clinical support for what the researchers had observed in their initial studies on mice models.
The team are now conducting a pilot study in a group of women with breast cancer to see if treatment with propranolol will reduce their risk of the tumour spreading to other parts of the body.
You can learn more about Dr Sloan’s research which was featured on the ABC’s Catalyst program in June 2016.
If you’d like to support breast cancer researchers like Dr Erica Sloan, you can donate here.