Can Stress Cause Cancer?

MD Anderson Cancer Center
Date: 1/31/2011

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Mark Ruff: Welcome to Cancer Newsline, a weekly podcast series from the University of Texas, M.D. Anderson Cancer Center. Cancer Newsline helps you stay current with the news on cancer research, diagnosis, treatment and prevention providing the latest information on reducing your family's cancer risk. I'm your host Mark Ruff and today we're talking with Dr. Lorenzo Cohen, Professor and Director of Integrated Medicine and Dr. Anil Sood, Professor of Translational Research in Gynecologic Oncology. Good morning.

Dr. Anil Sood: Good morning.

Dr. Lorenzo Cohen: Hello.

Mark Ruff: Today we're gonna talk about stress and cancer and the relationship between the emotion n and the disease. What do we know about stress and how does that affect our health mainly our bodies?

Dr. Lorenzo Cohen: Well, we know that psychological stress can actually have a profound effect on our health, general wellbeing, and actually biological functioning. But before we get into some of the details of the research, its important to really define what we mean by stress and there's often a misunderstanding between the term stress and stressor. And stress is really how somebody responds both psychologically, physiologically, and behaviorally in terms of how you cope when you're experiencing a stressor and a stressor by definition is an event that happens to an individual that is either challenging, overwhelming, it could represent loss or aspects of fear and stimulates this emotional response that comes from the interpretation of an event being something that is overwhelming to the individual in terms of how they can cope with this. And so a challenge in the research has been in how it is defined, this concept of stress, and more often than not, they're talking about measuring stressors and what's the relationship between stressors and risk of disease or progression of disease when you are already diagnosed with the disease. And last, this concept of stress in terms of how do somebody actually respond to the event. So an example would be that two individuals could experience bereavement, the loss of a loved one and respond to it in very different ways. So the event itself is the same for both people. So in terms of a research that's doing just a check box of have you experienced these difficult events, doesn't get into the complexity of how somebody responds to those events. And then, more complicating in the situation is the fact that there is both acute and chronic situation and there's a difference when somebody has an acute stressors that they're dealing with that then goes away versus something that is chronic for an extended period of time. Then I think from physiology and biology, there are some adaptive aspects of responding in an acute fashion to situations versus when that becomes chronic. And so maybe Anil you could speak a little bit to this biology of acute stress and why it's in theory good for us.

Dr. Anil Sood: So just like Dr. Cohen mentioned that acute stressors are actually a very normal part of our life and it's very adaptive in the sense that it helps us respond to those kinds of settings. So some--an example of acute stress in some ways would be somebody getting up to give a talk in a public setting. And as soon as they finish the talk, their stress hormones will subside very quickly so there are many examples like that where acute stress can actually be quite good. It helps you function better. It helps you--it helps your immune system. There are many aspects about it that are actually positive. But like most things in life, when you have too much of something it can turn into a bad effect as well. So just like, you know, people who drink one glass of wine a day quite, you know, it turns out that's actually probably not a bad thing. It may actually be good. But if somebody drinks 15 glasses of wine a day, eventually that's gonna catch up so that becomes more of a chronic issue, so same thing with the chronic stress. Now, what are some examples, I think Dr. Cohen already mentioned some examples. But we know that for example, caretakers of sick individuals where there's no end in sight. So for example, caretakers of Alzheimer's patients or even caretakers of cancer patient sometimes are the ones who are actually quite stressed on a chronic basis. So those are the--that's the setting where we tend to see more effects on health in terms of bad effects.

Mark Ruff: We talked about the acute and chronic, how does this feed into cancer?

Dr. Lorenzo Cohen: On the situation with cancer is probably more difficult to understand the role of stress in cancer compared to probably most other chronic diseases that our society suffers from, for example cardiovascular disease, or arthritis, asthma, where those diseases are somewhat complex but they're single diseases. Cancer of course is not a single disease. And even within what we believe a relatively homogenous cancer diagnosis like ovarian cancer, there are many different kinds of ovarian cancers. And so the role of stress becomes more complicated because the disease itself is complicated. What we do know is that if there is a role of stress in the etiology of disease, meaning your risk of developing cancer in the first place, it's probably relatively small. It is however, a factor that one can control. And there is stronger links between stress and cardiovascular disease, so not to say that it's not important to control your stress and there's a lot of evidence that we can get into some of this in this dialogue about the role of stress in physiological functioning all the way down into how ourselves function. Where there is more evidence is the role of stress in progression of disease once you're diagnose with cancer and the role of stress as a risk factor for worst outcomes. Both worse outcomes in terms of a patients quality of life and adjustment but also in terms of overall survival or recurrence of a disease. And there has been some med analyses published that for example have shown the length between depression at the time of diagnosis and the length of life. And so this is an area that is still developing in terms of research but something that the patients really need to try and manage in their lives to be able to have better outcomes.

Mark Ruff: Dr. Sood, can you elaborate more on the chronic part of stress?

Dr. Anil Sood: Absolutely, so the--we've--over the last several years learned quite a bit about how chronic stress can affect both patients with cancer as well as even those individuals who don't have cancer. Its been well established that chronic stress can affect the immune systems so that people tend to be more susceptible to developing infections that they tend to have--be at more risk for heart disease so that they are a greater risk for developing heart attacks and that even their recovery is altered depending on chronic stress. With regard to cancer, we think about it in a way that if chronic stress has so many bad effects on the body, why would stress--why would cancer be immune in a lot of ways? I think we just need to learn more about how is it that chronic stress can make cancer grow even faster and that people tend to have a worse outcome. Well some of the examples that we've learned are that as the immune system is hijacked by cancers, stress can aggravate that situation even further and can actually tilt the balance towards some of the immune parameters even promoting tumor growth. Now we're learning that there are many other aspects of biology that are affected by chronic stress. Some of those that we've learned over the recent years include that under chronic stress settings, the stress hormones actually promote the blood supply to cancers. So as the environment within a cancer becomes more conducive to growth and spread the cancers tend to behave more aggressively. We've also made observations and as well as others that cancer cells themselves express these receptors, these locks for a lot of the factors that are produced under chronic stress so they can be directly stimulated, such that chronic stress can protect cancer cells from dying. So again, it creates a net effect where by cancers tend to have an altered immune system, they tend to have a greater blood supply, and they tend to survived better under settings of chronic stress the net effect being that there is greater cancer growth and progression.

Mark Ruff: We just lost our father-in-law to multiple myeloma and in the last probably week or so, we have seen a lot of stress upon that. My mother-in-law would always state, you know, I may end up getting sick because I'm stressed out because of this. And just straight to the point, I mean can stress increase a person's risk for cancer?

Dr. Anil Sood: Again, it's a great question and that is a question where there is some controversy. I think the Dr. Cohen alluded to that earlier, that the link between stress causing cancer is really not that strong overall. And if there is an effect, that tends to be perhaps a bit weaker. What we do know where the links are much stronger are that stress can make--chronic stress can make cancers grow faster so that individuals with cancer tend to have a worse outcome.

Mark Ruff: Okay, so what effect does stress have on the healing and treatment of, you know, their diagnosis of cancer?

Dr. Anil Sood: With regard to the diagnosis of cancer, what we are trying to study right now is at every level from the cell level to the animal models to human level. What are the different aspects? What are the biomarkers? What are the different aspects of cancer that are altered and clearly, there are number of effects that occur in a human setting as well. And then the next steps are what we're looking for are opportunities to identify those at the greatest risk for having a worst outcome from stress, and then trying to design interventions to try to block some of the deleterious effects of stress on cancer growth. And there are many opportunities for that including by behavioral approaches as well as pharmacological or medication based approaches. And I think Dr. Cohen can certainly discuss in more detail what some of the biobehavioral approaches are as well.

Mark Ruff: Dr. Cohen?

Dr. Lorenzo Cohen: That the key issue here is that even though there isn't definitive data linking stress to certainly risk of disease and definitive data saying that the more stressed person doesn't live as long. The overwhelming evidence that Dr. Sood has been describing is that stress has a profound effect on our biology and at minimums can increase vulnerability to progression of disease to some degree. And so it's important to try and get people who are undergoing tremendous degree of stress either independent of having cancer, being a caregiver, being somebody expressing bereavement like in your family, or somebody who's undergoing active treatment to try and manage their stress. And there's a number of different ways that people can do that. Some are quite conventional like conventional forms of psychotherapy or support groups, cognitive behavioral therapy has probably been one of the most researched conventional approaches where people learn specific behavioral skills for managing stress, things like progressive muscle relaxation, diagrammatic breathing, the use of guided inventory or self prognosis along with cognitive therapy which is quite important to help people deal with catastrophizing or black and white thinking and other forms of negative thoughts that there is specific techniques to help people manage those. And then there's some of the more non-conventional, you could say, approaches that come from eastern practices, mind-body practices such as meditation or yoga or tai chi, chi gong, the basis of all of these types of practices even the conventional western based practices is that it's important to try and dampen down the sympathetic nervous system response. So this fight or flight increase in stress hormones that happens when you're experiencing chronic stress that continues for extended periods of time is what can be quite damaging. And so, even if you're experiencing this stress, of course, 24 hours a day, if for an hour of time you are able to give the body a break, to quiet down the system, to calm the mind this will have also biological effects and ultimately could have an impact on the cancer. And so an example of this is a study that we did in men with prostate cancer who were gonna be undergoing surgery. And they participated in a stress management program and we showed not only were they less distressed prior to surgery but we also showed that their immune system 2 days after surgery was higher if they had participated in stress management before surgery than if they were in a controlled group who didn't learn any stress management skills. So to have both psychological benefit as well as biological benefit on components of the body that are relevant for healing.

Mark Ruff: Great. Thank you for elaborating on that. That was going to be my last question on that because I mean, cancer just adds another dynamic to the equation. I mean, we have the economy, we have people at their job and to manage stress, I mean, it's difficult for anybody, you know, for you and I also. Do you have any closing thoughts, Dr. Cohen?

Dr. Lorenzo Cohen: I think the key is that people find something that works for them. Different types of interventions are going to be useful for different people in certain situations, it may be important to have pharmacological drugs involved, antidepressants or anti-anxiety medications. Most people don't want to be taking extra pharmacological medications with all the other treatments that they're on under active treatment. And so in the best case scenario is to try and harness the benefits that can come from some of the behavioral therapies. And if you try something like yoga or meditation and it doesn't work for you then you can switch and try something else. The key is to keep trying things, find something that helps you to manage your stress which of course can also include things like physical activity and engaging in support groups and listening to music and having a hobby, et cetera. And then the key is to do it on a regular basis.

Mark Ruff: Dr. Sood?

Dr. Anil Sood: So let me make 2 points actually. One is, Mark, to build on what you were getting at that at times when we're taking care of a cancer patient we forget the other individuals who may be actually quite stressed around them. And, so I think we need to think of treating cancer in a broader context as well. Treating perhaps not just the individual but also providing a mechanism by which we take care of those around them as well, which I think collectively will, if anything, provide better care for the patient themselves. The second point I want to make is that there is still I think stigma in the broader community associated with either seeking help for stress or for mental illness broadly. I think we need to have enough of a dialogue that we need to empower these individuals to seek help. That it's perfectly okay to seek help when they are experiencing states that they can't manage on their own. So those are really the 2 points that I want to make and again like Dr. Cohen mentioned I think the opportunities now for managing the bad effects of stress are continuing to expand and as we understand the biology better I think that if anything is going to continue to improve over the next several years.

Mark Ruff: I want to thank Dr. Cohen and Dr. Sood for joining me today. If you have any questions about anything you heard today on Cancer Newsline contact Ask M.D. Anderson at 1877-MDA-6789 [background music] or online at www.mdanderson.org Thank you for listening to this episode of Cancer Newsline. Tune in next week for the next podcast on our series.