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Welcome to The Breastcancer.org Podcast, the podcast that brings you the latest information on breast cancer research, treatments, side effects, and survivorship issues through expert interviews, as well as personal stories from people affected by breast cancer. Here’s your host, Breastcancer.org Senior Editor, Jamie DePolo.
Jamie DePolo: Hello, I’m Jamie DePolo, senior editor at Breastcancer.org. I’m podcasting live from the 2025 American Society of Clinical Oncology annual meeting. My guest is Dr. Kathryn Schmitz, exercise oncology researcher at the UPMC Hillman Cancer Center, where she serves as the interim director. She’s also associate director of population sciences and founding director of the UPMC Moving Through Cancer Program. At this conference, she chaired a session on how to integrate exercise into cancer care, but there was also some very exciting research on exercise and colon cancer that I’d like to get her take on. Dr. Schmitz, welcome to the podcast.
Dr. Kathryn Schmitz: Thank you so much. It’s delightful to be with you.
Jamie DePolo: So, what were the takeaways from your session? How does exercise become more of an integral part of cancer care?
Dr. Kathryn Schmitz: Yeah. So, one of the things that I think we've missed up to this point that was really a big focus in our session, is the issue of triage and referral and the recognition that cancer survivors are not all one in the same. That, you know, there are people who are, you know, 75, have never exercised, relatively frail, haven't been in a gym, you know, in 40 years, and then there’s the 35-year-old who was playing, you know, doubles tennis last week before her diagnosis, and you’re not going to throw them in the same program.
They need different things, and the people who are qualified to do that triage and referral process are not the medical oncologists and not the nurses. And so, we have a number of different validated tools that’ve been developed, but this is work. This is part of the work of connecting people to appropriate exercise programming, and without this, we end up missing a great majority of patients, because if we assume everybody can go to Livestrong at the Y...which is a great program. I love Livestrong at the Y, but if we assume everybody can go there, we miss, like, 90% of patients.
Jamie DePolo: Well, and the other question that came up during the session, too, is, okay, this is great. Most of the research is, I think you pointed out, is, you know, six to 12 weeks of an exercise intervention. What happens after that, and can everybody afford that? You know, I guess, for me, it’s two questions. How do you motivate people to continue, and then who pays?
Dr. Kathryn Schmitz: Right. So, great news. There is actually a whole field out there called behavioral science, right? And so, the behavioral scientists have very reliable approaches to shaping behavior. You know, there is something called the Society for Behavioral Medicine, and those folks are absolutely at the top of the field of helping us to understand how to change people’s behaviors, including exercise behaviors, and we have to shape the behaviors slowly, in the same way that, you know, you don’t expect yourself to run 10 miles the first time you go out to run.
You expect yourself to walk for a mile the first time, and then you gradually shape yourself, and the same is true of all behaviors, all types of physical activity behaviors, and there are a variety of different theoretical models that underpin helping people to figure out that they have the capability, the opportunities, and the motivation to participate in physical activity.
And I know you're going to ask me about the CHALLENGE trial, which was in colon cancer. And so, I will just underpin that this extremely important and very exciting trial absolutely had behavioral science underpinnings, and the reason why they were able to get the participants to do the exercise is not because they gave them a gym membership or because they just simply told them to. They were using behavioral science, something called the theory of planned behavior, to point out the capabilities, opportunities, and motivation opportunities for the patients to be able to get them to stick with the exercise for three years.
Jamie DePolo: That’s a long time, and so, before we get to the CHALLENGE trial, which I was very excited about, what about cost? You know, because somebody...like, I don't know that everybody can afford to go to a gym. I know Livestrong is low cost or no cost, but that can be hard for a lot of people.
Dr. Kathryn Schmitz: Absolutely. So, there are a number of answers here. The first one is that I am leading an initiative, through the American College of Sports Medicine and the Moving Through Cancer initiative, to try to get CMS to cover exercise oncology support for people over 65 who have cancer, and in the effort to do that, we’ve had to present some cost effectiveness data, and, in the evidence base, and you know, I sent the CHALLENGE trial paper to my contact at CMS immediately on Sunday, and she wrote back and said let’s have a call soon.
So, you know, hopefully, it’s influential. I think cost is a major issue, but I think that, at the end of the day, one of the things that we have to be starting to pay attention to is the difference in the cost for these extremely expensive drugs, as opposed to the cost of doing the exercise program. Kerry Courneya, who’s the first author of the CHALLENGE trial, has estimated that his program will cost about $5,000, as opposed to how many tens of thousands, if not millions of dollars, for the drugs that are treating cancer.
Jamie DePolo: Exactly, and so, we’ve hinted at the CHALLENGE trial. I’ll just say it was done in stage III colon cancer, so a very specific population, but to me, the extremely exciting part was they found that the exercise program improved progression-free survival, so the time until the cancer grew, or came back, I should say, recurrence, rather, and overall survival. So, exercising allowed people to live longer, which, I guess to me, that could be a huge motivator for people.
Dr. Kathryn Schmitz: Yeah, 28% reduction in disease-free survival, 37% improvement in overall survival by the time we got out to about eight years in CHALLENGE. So, this is the first randomized control trial evidence of its kind, published in The New England Journal of Medicine yesterday morning, and you know, it is quite possibly the most important finding in the field of exercise oncology in my career, you know, in the period that I’ve been working in the field. I am super excited about it.
Jamie DePolo: Well, let me ask you this. I know it was a very specific population of colon cancer, but I can’t help but think that it could...I mean, I know we can’t say it, but it could apply to many different types of cancer.
Dr. Kathryn Schmitz: It absolutely could, and one of the things to also point out, based on the organization you’re from, is that one of the secondary cancers that were prevented were breast cancers. So, there was a substantive difference in the number of breast cancer second primary tumors in the treatment group as opposed to the control group. So, for people who are survivors of colon cancer, that is not a get out of jail free card for other cancer diagnoses. Clearly, about 20% of their population had a second primary, and most of those were breast.
Jamie DePolo: Okay, and just you mentioned this, too, but the exercise program that the people did in the study, it was three years long, and I'm also amazed by that. I mean, I think that’s great because you need to continue to do it to continue to get the benefits, but if you know this, if this isn’t too broad a field, I know that people could do a lot of things, whatever they liked, whether it was hiking, kayaking, and then did a trainer help them with that, help them get ready, because you mentioned the behavioral science?
Dr. Kathryn Schmitz: Yeah. So, the goal was, to put it into exercise science parlance, they were supposed to be doing 10 MET hours a week of aerobic activity, and what that translated into is, like, 3 1/2 to 4 hours of aerobic activity of moderate intensity over the course of a week, and they could do it any way they wanted to. Most of the people were doing brisk walking. When the weather was not good, then they could choose to do a stationary bike or walk up and down their stairs or you know, a variety of other things.
Kayaking, certainly, hiking, you know, anything that they can get to, but I actually really love the fact that it was done in a way that they weren’t asked to go anywhere in particular for most of the exercise. They were doing this on their own in their communities, in their homes, in their...you know, fitting it into their lifestyles. So, I think that that speaks well to the potential for integrating this into the lives of cancer survivors, and I absolutely think that these findings are likely to be consistent for breast and prostate, based on the observational data.
Jamie DePolo: And one final question. When Dr. Booth presented the research, he noted that they saw the benefits, whether or not people lost weight, which I thought was very interesting, because there’s such a drumbeat, I guess, that, you know, if you gain weight after a cancer diagnosis, especially with breast cancer, increases the risk of recurrence, and so, I thought that was pretty remarkable, too, because it kind of like takes that pressure off. It’s just like, go out. Enjoy yourself. Move around. Don’t worry about losing weight. Just move.
Dr. Kathryn Schmitz: Absolutely. Absolutely. So, this is, you know, very much going to go with body positivity, you know, and getting people moving at any weight and any body shape. You know, fitness is for every body, and I love the fact that the results were independent of body weight, because it does tell people, we can control our exercise behaviors. We cannot control as much what happens with our body weight even...
You know, there are plenty of people that are listening to this who have, you know, changed their eating habits and their exercise habits and not seen measurable changes on the scale, and that is so frustrating, you know? So, the algorithm for, you know, how weight changes is clearly more complex than we have been able to, you know, completely unpack at this time. So, the great news is it doesn't matter whether or not you are losing weight as you’re doing your exercise. In fact, you probably won’t lose weight as you’re doing the exercise.
But it is still benefitting you, likely having to do with inflammation and you know, the tumor microenvironment, and you know, cytokine release and a number of other mechanisms that were outlined in the presentation yesterday. I actually think that that was a happy finding in order for us to be able to underscore to people that there is value to exercise, real value for survival benefit, over and beyond anything that would happen on the scale.
Jamie DePolo: Dr. Schmitz, thank you so much.
Dr. Kathryn Schmitz: You are so welcome. Thanks.
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