Exercise as medicine: physical activity is vital before, during, and after cancer

Prof. Dr Nele Adriaenssens combines research at the Vrije Universiteit Brussel (VUB) with clinical work at UZ Brussel, making her an expert on the importance of exercise for cancer patients. "Exercise is a gamechanger in oncology."

For people with cancer, physical exercise is much more than a healthy habit: it is an essential part of their care and treatment journey. In this interview, we dive into the science behind movement. Can it increase survival rates? Does it help manage side effects?

Prof. Dr Nele Adriaenssens is Oncology Rehabilitation Coordinator at the University Hospital Brussels - Cancer Center Brussels and Associate-Professor in Rehabilitation Research, Oncology-Lymphology, Vrije Universiteit Brussel (VUB).

Exercise and Cancer: What is Required?

First and foremost, what is exercise? It can range from being active and hitting 5,000 steps a day to exercising for half an hour four times a week. What is relevant for someone who has cancer?

"Movement is, of course, a very broad and comprehensive term, and it can indeed include all sorts of things. I think we are already moving a lot in our daily lives. But it is a different matter when we start playing sports or engaging in structured exercise therapy. Then you are on a different level; it is much more intensive. What we recommend to everyone facing a cancer diagnosis is a physically active lifestyle. But that is actually true for all of us, including healthy people.

There are a number of guidelines from the World Health Organization. For example, 150 minutes of moderate-intensity movement per week, to pursue a healthy lifestyle. Additionally, you have the 5,000 or 10,000 steps a day that we aim for. These are all good tools to check whether we are indeed in balance and/or whether we are exercising enough.

However, when we talk about exercise therapy and focus on recovery for our cancer patients, we work according to guidelines from organisations such as the Royal Dutch Society for Physical Therapy (KNGF), the American Society of Clinical Oncology (ASCO), and the American College of Sports Medicine (ACSM). These guidelines quickly lead us to aerobic training three times a week. That means endurance training. This could be on a treadmill, an stationary bike, or even just walking at a specific speed. This varies for everyone, of course. Strength training is also recommended. You don't have to become a bodybuilder, but it is beneficial to strengthen your muscles, and that is exactly what we aim for with rehabilitation programmes for this target group."

Exercising during chemotherapy

How can exercise help someone who is undergoing treatment, for example receiving chemotherapy? What might he or she experience or feel?

"Moving during chemotherapy, as well as during other therapies, is very important. Unfortunately, this is not always highlighted enough, but we know from the literature and our own ongoing studies that it is vital to keep moving, or to start moving, during chemotherapy.

What are the effects of staying active during chemo? One objective is to maintain body composition: keeping fat mass and muscle mass at a healthy level. During chemotherapy, a lot of toxicity is released into the body, and we want to prevent the body from weakening. There is scientific evidence that if patients can maintain their body composition during treatment, they will rehabilitate much faster and better afterwards. This allows them to reintegrate into daily life more effectively, which is certainly a key goal.

Furthermore, we see that tolerance, or the ability to endure chemotherapy, is a significant outcome when patients exercise during treatment. They experience fewer side effects, allowing them to sustain the treatment better and for longer. This, in turn, has a positive effect on psychosocial well-being. If you cannot receive the full dose or the planned number of sessions, it can start to weigh on the mind; patients may fear they have a lower chance of survival or that the cancer might return. Indirectly, this affects survival chances. If you can undergo the full dose of chemotherapy without too many interruptions or dose reductions, that is a major advantage. That is why we hope to achieve a better quality of life for patients through exercise during chemotherapy. And, that is ultimately what we are doing it for."

The CHALLENGE study

Can you highlight a recent study that is particularly relevant?

"Last year, a very large study was published involving many patients across different countries. It was a Phase 3 trial, meaning the research was very advanced, comparing a control group with an intervention group in bowel cancer. The control group received advice on being physically active and pursuing a healthy lifestyle, while the other group was encouraged to continue exercising for up to three years after treatment. They were given a physical activity programme coupled with a behavioural change component. The participants were motivated and the importance of the exercise was explained to them.

After the three-year follow-up, they found that patients in the active group, those who exercised, had much better survival chances. It wasn't just "overall survival", the cancer itself had not returned as often. This is a very significant, recent study within the bowel cancer population, and we are now building upon these findings.

It is the first time such a large study has been published showing that exercise can truly be a "medicine" against cancer: against recurrence and also to improve survival. That is a gamechanger. The study has strongly influenced our field, and it is accelerating the application of these exercise therapy protocols to other groups of people living with or after cancer."

Is exercise currently included in cancer treatment protocols?

"I will try to answer that diplomatically. We have the evidence, the science is there, the foundation is there. We know that moving is incredibly important, even starting with cancer prevention. Yet, unfortunately, for example, regarding reimbursement in the physiotherapy nomenclature, there is currently no specific code we can use to ensure such a programme is reimbursed for patients with or after cancer.

Today, we have to wait until a patient develops certain side effects that we can then "use" as a starting point for reimbursement. Naturally, we would much prefer to intervene earlier, offering exercise as a standard package to all patients who need it. And that is indeed the vast majority of patients who receive a cancer diagnosis."

Preventing cancer

Exercise is also encouraged as a preventive measure against cancer. Can you briefly explain its importance?

"The importance of exercise in cancer prevention is an excellent question. Existing evidence shows that for people with a physically active lifestyle, the risk of developing seven to eight types of cancer decreases. So, we can actually prevent cancer as healthy individuals by pursuing an active lifestyle, and that is a vital point. I am talking here about primary prevention: preventing the onset or development of cancer.

But then, of course, you also have secondary prevention, where we reduce the chance of recurrence for people who have already had a cancer diagnosis. This is also crucial, and exercise can help here too. Exercise plays a key role from prevention all the way through to the end-of-life phase."

A call to action: "Just Move"

What else needs to happen? What is your personal call to action?

"What needs to "move" more is our patients and even everyone else before they become a patient. Our programme at UZ Brussel is called "Just Move," and that name was chosen for a reason. We are very pleased to know that positive effects begin the moment people simply start moving. Especially for those who have had a sedentary, inactive lifestyle. This is the moment to get started and quite literally get moving. Exercise can prevent so many problems and reduce many side effects during treatment.

The importance of movement is undeniable, but unfortunately, it is perhaps not yet sufficiently known by most patients or healthcare providers. In an ideal world, all healthcare providers would refer patients for rehabilitation programmes or a more active lifestyle, and that is what we are currently waiting for."

Why is it important for every patient to have their own personalised exercise programme?

"We are very happy when patients have an active lifestyle before, during, and after treatment. But it is even better to follow a supervised rehabilitation programme. At UZ Brussel, this often happens in groups, which allows for contact with peers. Patients follow an exercise programme together at the same time, but the programme is tailored to each individual because every patient has different needs, requirements, and goals.

We work with the patients to find out what is important to them in their daily lives. Some patients need to return to work or resume their roles within the family. It is important to incorporate that into the programme. Patients also often experience different side effects; we investigate with the patient what bothers them most and then try to address those issues.

Our programmes are primarily focused on reconditioning, strengthening endurance and physical fitness. However, there are many other issues patients can experience. For example, lymphoedema, where swelling occurs after surgery because lymph nodes were removed. This is something we have to tackle separately using manual techniques. We cannot solve that with a group programme alone. Therefore, it is essential to look at everything in consultation with the patient and the interprofessional medical team to develop a tailored programme for every patient, achieving the best and most efficient results."