Tuesday, 28 June 2016 Stress and Cancer Stress and Cancer Every day in Australia 360 people learn they have cancer. It goes without saying its a very stressful time. Stress as a cause of cancer has not been convincingly proven but recently researchers have been looking at how stress drives the spread of an existing cancer from the original tumour. Theyve identified pathways caused by stress that facilitate the spread of breast cancer cells around the body. Whats more remarkable, the researchers may have found a way to prevent it. Guest reporter, oncologist Dr Ranjana Srivastava investigates. * Stress and Cancer * * -- NARRATION Every day in Australia, 360 people learn they have cancer. It goes without saying, it's a very stressful time. I often think about how stress affects my patient's prognosis. And it's an issue the medical community has long debated. Dr Ranjana Srivastava -- Yeah. This is the first one. NARRATION From my own clinical experience, it does seem that stress has a negative effect on cancer outcomes. But to date, we haven't had good science to know how this happens. Dr Ranjana Srivastava New Australian research has identified pathways caused by stress that facilitate the movement of cancer cells around the body. Dr Erica Sloane The stress is sort of acting like a fertiliser and helping the tumour cell take hold and colonise those other organs. NARRATION -- No, you can't blame the chemo for being bad-tempered. NARRATION Robert's making light of it, but stress is now proving a real factor in cancer spread. Challenging circumstances activate our body's fight or flight response. In times of threat, this allows us to respond quickly. But if it becomes chronic, stress can have damaging effects on our health. It's associated with greater risk for depression, heart disease, and infectious diseases. When it comes to cancer, stress as a cause has not been convincingly proven. But over the last 10 years, Dr Erica Sloane's lab has been looking at how stress drives metastases - that is, the spread of an existing cancer from the original tumour. Dr Erica Sloane At the time that I started this research, we had an understanding of how stress affected cancer patients at a psychological level, but we really didn't understand how stress got into the body of a cancer patient and how it could affect the cancer cells. And what we found was that when a mouse has cancer, when they're stressed, the cancer hears that and it 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. -- pathway to track right through the body. NARRATION Very recently, Erica's lab discovered that stress co-opts this lymphatic network to create new, faster pathways of escape for cancer cells from a primary tumour. This research by Erica's colleague, Dr -- in mice. Dr Ranjana Srivastava Human stress is so multifactorial. Explain to me how you stress mice. Dr Caroline Lee What happens when you're stressed is you get a release of these stress hormones that then prepare your body for threat. So, the way that we mimic this in mice is through a method we call restraint stress, which is essentially just putting them into a confined space. And this activates the same pathways as humans have activated when they're in stressful situations. Dr Ranjana Srivastava Alright, so, I can understand that that's a physiological stress that you are imposing on the mice. How do you measure psychological stress, which, as I see every day, is such an important component of cancer? Dr Caroline Le Mice actually do like being in small, confined spaces. The part that they don't like is not being able to escape, and so when we stress them in these confined spaces, this activates the psychological fear factor, or the coping mechanism that we see in humans, which then leads to these physiological responses that we then can measure later. NARRATION Stressed and unstressed mice are injected with human tumour cells. These cells are tagged with a protein extracted from nature, from fireflies, so they emit light. -- NARRATION Using this, and other imaging techniques, Caroline has found that stress increases the number and size of lymphatic vessels leading out of a primary tumour. Dr Caroline Le So, what you can see is that the flow in the mouse under stress conditions flows much faster than that in the mouse under control conditions. -- Right. NARRATION These stress-induced superhighways dramatically increase the number and size of metastases. Dr Caroline Le So, you see six times more spread of cancer in stress mice compared to control mice. NARRATION Given that metastasis is behind the vast majority of cancer deaths and that stress is an inevitable part of having cancer, it's cruel news. Patient It's hard not to think about, you know, that I do have cancer and at -- have a brand-new role in tackling cancer. Beta-blockers are commonly used for high blood pressure and cardiac arrhythmia, but they're also known to control the effects of stress. Dr Erica Sloane They work by blocking the stress response. And so if you have a beta-blocker present, then the beta-blocker will get in the way of adrenaline and stop it binding, and so heart rate doesn't go up as much, blood pressure won't go as high. NARRATION When the beta-blocker propranolol was given to stressed mice, the effects of stress were totally negated. Dr Caroline Le What we then see is that stress no longer restructures the lymphatic system and we don't get this increase in spread of cancer in response to stress. NARRATION Although generally a safe medication, beta-blockers are not without side effects. Drawing on their knowledge of how stress acts on cancer cells, the researchers hope to develop a cancer-specific beta-blocker. Dr Erica Sloane -- Dr Jonathan Hiller We've chosen the perioperative period, 'cause 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 their diagnosis can be incredibly anxiety-provoking. -- Angela O'Regan In my mind, I think I did have the right tablet. I definitely felt less stressed. I definitely...I definitely did feel less stressed. But I don't know if that was that, or if it was in my mind. Professor Michael Henderson -- Surgery is often the first stage of treatment for breast cancer. And despite all their care, surgery is an assault on the body, inducing a stress response that is similar to that caused by traumatic injury. Dr Jonathan Hiller Patients are exposed to a lot of stress through the surgery and not just their anxiety. They're exposed to pain through to hypothermia, a number of medications related to their anaesthetic. So we often see states of stress and what we call inflammatory stress - inflammatory response is a direct result from surgery and well known to exist. Dr Ranjana Srivastava Participants' stress levels are analysed through blood samples taken before and after surgery. Dr Jonathan Hiller There are markers in the white cells that circulate in our body that reflect our overall state of stress and anxiety. We want to see whether using beta-blockers changes that signature at the time of surgery. We're very keen to see whether the medication changes the behaviour of -- The trial is ongoing, but I'll certainly be very interested in the results. Angela's own surgery went well. She's having chemotherapy and, in the meantime, trying to keep her stress levels under control without medication. Topics: Health -- Recent published research study by Drs Caroline Le and Erica Sloan on stress and cancer Dr Erica Sloans lab at MIPS -- A very interesting program. I am intrigued that the described pharmacological intervention appeared to be the preferred approach given that there are other stress management strategies for which the evidence is persuasive and which have the advantages of conferring upon the person a sense of personal agency/ self efficacy. For example, -- Would love to hear how you relate Kelly McGonigal's research to this story - that it's our beliefs around stress rather than the stress itself that predicts health outcomes. She refers to n=30,000 8-year longitudinal study that found that all-cause mortality was lowest in those with high stress but believed that stress is a useful and a necessary part of life. Interesting research - I wonder how/if it can be applied to this evening's story. -- * Staying Up Late * Stentrode * Stress and Cancer * Sun Damage * Sun Damage