ASCO 2019: Diet, Exercise, and Breast Cancer Outcomes
Dr. Basen-Engquist’s research focuses on cancer survivors and how health behavior interventions can reduce the severity of late-term side effects, improve physical function, optimize quality of life, and reduce the risk of chronic diseases. She also studies ways to help people make behavior changes and ways to assess symptoms and behavior in cancer patients and survivors.
Listen to the podcast to hear Dr. Basen-Engquist talk about:
how to talk about diet and exercise with your doctor
why exercise and maintaining a healthy weight should be part of every person's long-term cancer care
how people who are feeling overwhelmed about having to make a lot of diet, weight, and exercise changes can start slowly to improve their health
Dr. Karen Basen-Engquist is professor of behavioral science and director of the Center for Energy Balance in Cancer Prevention and Survivorship at the University of Texas MD Anderson Cancer Center.
— Last updated on May 5, 2022, 6:35 PM
This content made possible by Lilly Oncology.
This podcast is made possible by the generous support of Lilly Oncology.
Jamie DePolo: Hello, and welcome to the Breastcancer.org podcast. I’m Jamie DePolo, senior editor of Breastcancer.org. We’re on location at the [American Society of Clinical Oncology Annual Meeting.] My guest is Dr. Karen Basen-Engquist, professor of behavioral science and director of the Center for Energy Balance and Cancer Prevention and Survivorship at the University of Texas, MD Anderson Cancer Center. Dr. Basen-Engquist’s research focuses on how life and lifestyle modifications can reduce the severity of long-term side effects and improve quality of life and physical function in cancer survivors.
Today, Dr. Basen-Engquist presented information on research on how people diagnosed with breast cancer can lose weight and exercise more, as well as how those modifications can affect the risk of recurrence. Dr. Basen-Engquist, welcome to the podcast.
Karen Basen-Engquist: Thank you so much for having me, Jamie. I’m pleased to be here.
Jamie DePolo: So earlier today, during your presentation, you talked about research showing that breast cancer patients were more likely — actually I think it was just all cancer patients, in general — were more likely to make lifestyle changes related to diet, weight management, and exercise if their oncologist brought up those topics. If someone’s doctor doesn’t bring them up after a cancer diagnosis, do you think the person should bring that up? I mean, how should that get approached?
Karen Basen-Engquist: I think it’s a great conversation to have with your oncologist regardless of whether the oncologist or surgeon or whatever healthcare provider you’re speaking to, regardless of whether they bring it up. This is a health issue. What you eat, how active you are, what your weight is affects your health, and it is something you should talk to your healthcare provider about.
Jamie DePolo: Okay. Now, I’ve noticed at conferences lately, more and more researchers are starting to talk about weight management and exercise kind of just being part of long-term cancer care. Do you think…I mean, is that where we’re going?
Karen Basen-Engquist: I hope that’s where we’re going! I would like to see us go there. I think it is getting increasing attention. It’s getting attention partly because of the research you just mentioned, that was presented in the session, showing that obesity is associated with poorer outcomes for some cancers; physical activity is associated with better outcomes for some cancers; and also randomized trial data showing that physical activity and exercise can improve quality of life, decrease symptoms, improve well-being and physical functioning for people after cancer and during cancer treatment. So given that, I do think we’re seeing much more attention on this, much more movement toward addressing it in oncology care and in also post-treatment care in the survivorship period.
Just wanted to mention the American College of Sports Medicine, which is an organization that addresses and studies all aspects of exercise and exercise and health, has a subgroup that works on exercise and cancer. And they have, over the past year, been convening a round table to examine their previous recommendations for cancer survivors, rigorously reviewing the literature on the benefits for cancer survivors, also looking at this issue of how it should be implemented in care, and they will soon, I would say within the next 3 or 4 months, be releasing their revised recommendations for cancer survivors and patients. And we don’t know what those are yet, but I do not think they’re going to be backing off their recommendation that survivors and patients stay active after cancer diagnosis.
Jamie DePolo: Oh, that’ll be great. I have to tell you as an aside, I did a podcast with a trainer who is certified to work with cancer survivors. And she said what drives her a little bit crazy is that people don’t expect much, or I should say trainers, maybe even doctors, don’t expect much exercise-wise from survivors and people who are currently in treatment. They, like, “Oh, just go do some stuff on the elliptical, and that’s fine,” and she said, “I don’t do that. I challenge. I challenge my clients.” And she said, “I think they appreciate it, because they’re really stronger than they think.”
Karen Basen-Engquist: Yeah. I think that is true, and having that personal trainer can kind of help push you a little bit farther. However, I would say the other thing to keep in mind is that the kind of biggest improvement we see in people is the people who go from doing nothing to doing anything. So even if you feel like you’re not ready to be pushed, it’s important to get up, take some extra steps, you know, break up your sedentary behavior during the day so that you’re not consistently sitting the whole day through. You know, a lot of us have desk jobs and we sit a lot, but it’s important to take breaks and get up and walk around. So even doing that as a first step to getting active is important, even if you feel like you’re not quite ready to have that trainer push you. I agree, most of us could do more than we think we can do, even if we’re being treated for cancer, but it’s important to even take those early steps towards being more active.
Jamie DePolo: No. I didn’t mean to suggest she was pushing them to far, but she was saying, you know, even, like you said, sitting in a chair and lifting some soup cans is a great way to start.
Karen Basen-Engquist: Yeah. Absolutely.
Jamie DePolo: Anyway, but I digress. So, I was tweeting during your presentation where you suggested that weight loss could potentially reduce the risk of breast cancer recurrence. And I immediately got a reply from someone who is currently in treatment who said, “Well, that’s great, but a side effect of my treatment is weight gain.” So, could you talk about that a little bit?
Karen Basen-Engquist: Sure, and it is frustrating. In breast cancer in particular we see weight gain a lot in the course of treatment. And just to clarify, the data that we have right now shows that being obese is associated with a higher risk of recurrence. We don’t yet know if weight loss affects recurrence risk. There’s some mixed data on that, and of course the randomized trials like the one that Dr. Ligibel talked about, the BWEL trial, will hopefully provide us with some answers with regard to that.
But yes, I’m sure that it’s really frightening to see data like that showing that obesity is associated with an increased risk of recurrence, and knowing that through your treatment you have gained weight. But I think it underlines the importance of taking some action to try to manage that weight gain. I mean, even though the treatment is associated with weight gain, it’s not inevitable, and you can manage it and perhaps kind of reduce the amount of weight gain with exercise. Exercise and a healthy diet that’s calorie restricted still will work to help you minimize that weight gain or maybe even prevent it from happening.
Jamie DePolo: Okay. I think it’s especially important, too, because now with the recommendations, people could potentially be on AIs for 10 years.
Karen Basen-Engquist: Right. Right.
Jamie DePolo: You know, some people are already on tamoxifen for 10 years. That’s a long time to be in treatment and to worry about weight gain.
Karen Basen-Engquist: That is a long time, and we know that AIs are associated with some fatigue, with joint aches and pains for many people, so that can make it harder. If you’re managing that, it makes it harder to think about… you know, it’s like you kind of want to go to your dish of ice cream to make you feel better, right?
Jamie DePolo: Absolutely.
Karen Basen-Engquist: But I think exercise has been shown to help remedy some of those side effects of AI therapy, particularly the joint pain and muscle pain and fatigue, and I think we also know… We don’t know for sure if weight management helps reduce those symptoms. We do know that people who are heavier, they put more stress on their joints, so it seems kind of logical to think that managing your weight might also help with some of those side effects.
Jamie DePolo: Okay. So you talked about in your presentation, too, that BMI is kind of an imperfect assessment of body fat, especially in older women. And obviously not all, but a majority of people diagnosed with breast cancer are older women. So I guess what I’m wondering, it seems like some of the studies — and maybe I’m not interpreting them exactly correctly — but they show that maybe just exercising more can really add a lot of health benefits. Even if you don’t change your diet, and even if you don’t lose a ton of weight, you’re just kind of changing your body composition. Are there studies looking at that? Does that sound possible?
Karen Basen-Engquist: So, it does sound possible. We have observational studies that show that breast cancer survivors who are more physically active after breast cancer treatment, or after diagnosis, have a lower risk of recurrence. So independent of what their BMI is, being more physically active does reduce your risk. And of course, we talked about some of the benefits of exercise as kind of reducing some of those side effects, helping you deal with the fatigue, and so forth. So even if you don’t lose weight, exercising does have a benefit.
Jamie DePolo: Okay. Okay. That’s good to know, because I think some people hear, “Well, I have to exercise more, I have to lose weight, and I have to change my diet,” and it seems like a lot to do all at once while you could potentially still be in treatment.
Karen Basen-Engquist: Right. It can be very overwhelming. And I think one of the things we want to try to avoid is kind of overwhelming people with the responsibility. I think that patients do often feel grateful that there’s something that they can do to help improve their health, but if it gets overwhelming and you start to feel guilty and upset that you’re not able to perfectly adhere, it’s time to sort of back off and reassess, and maybe talk to a mental health professional about how to balance it all, or just even a friend or your oncologist. Maybe you want to start with one thing at a time, you know, start with the exercise or start with healthier diet or something like that, and then build up. Because I think there’s not really any benefit to be gained, I think, in overwhelming patients and making them feel bad because they aren’t able to make certain changes. So, that doesn’t lead to behavior change, first of all, it just makes the person feel worse, so we don’t want that.
Jamie DePolo: So if you had to pick one, I mean, would it be fair — and again, this is me making a scientific decision — would it be fair to say to start with exercise because that seems to offer a lot of benefits?
Karen Basen-Engquist: That’s a good question. I think… So most of my research is in exercise, so that is kind of my bias.
Jamie DePolo: That’s your niche. Yeah.
Karen Basen-Engquist: I would say exercise is important. But I think doing things that are sort of consistent with your values, too, all of those things are good. You know, eating a healthier diet, managing your weight through calorie restriction, being more physically active, they’re all good things to do for yourself. And so if something fits better for you, and that’s what you want to start with, go ahead and do that.
Jamie DePolo: Okay. Okay. That makes good sense. So, also in the presentation, for my last question, studies have looked at low-fat diets, studies have looked at reducing calories and both breast cancer risk as well as recurrence risk. And then other studies I’ve seen not necessarily connected to cancer have suggested that maybe fat isn’t the nutrient that should be demonized, you know, maybe we should be looking at sugar, or maybe we should be looking at some of the things that make processed foods. Do you know of any studies that are looking specifically at those and cancer risk, like sugar and cancer risk or processed foods and cancer risk, anything like that?
Karen Basen-Engquist: So, we don’t have studies on the scale of some of those randomized trials that were looking at low-fat diets. And I think, you know, you are right that our thinking about fat has evolved a lot. At the time those studies were done, we were trying to reduce all kinds of fat. Now we mainly focus on saturated fat and trans fats, which are the most damaging to health, right? Those are the fats that are associated with more clogged arteries, also apparently higher cancer risk, whereas monounsaturated fats like in olive oil and canola oil, it’s actually good for us to have some of those. So our thinking about fat has changed a lot.
As far as the question of whether there are trials that are testing some of those other components of diet, at this point it’s mainly smaller-scale trials. We don’t have the really large trials as were done on the low-fat diet, and we have large weight loss trials. So one of the things that sort of has come out of a lot of the combined literature on nutrition is that managing weight seems to be quite important for health for all kinds of people, not just cancer survivors. So there’s been an increased focus on managing weight and less focus on specific nutrients. But we are seeing some smaller studies and trials emerge on things like plant-based diets, sometimes ketogenic diets, there’s interest in that area, limiting sugar and so forth. But the jury is still out. We still don’t know a lot about those. What we mainly know about those specific kinds of foods is from epidemiologic studies.
Jamie DePolo: Okay. Thank you very much. I appreciate your insights.
Karen Basen-Engquist: My pleasure. Thanks for having me.