How Muscle Mass and Movement Can Help Tolerate Chemotherapy
Chemotherapy is a powerful weapon in the fight against breast cancer, but unfortunately, it often comes with unpleasant side effects (Figure 1). Think of tingling or numbness in the hands and feet, muscle weakness, or a weakened immune system. For some patients, these side effects are so severe that their treatment must be adjusted or paused. But why do some patients experience these side effects more intensely than others? The PABTOX project, a collaboration between the Vrije Universiteit Brussel, UZ Brussel, and Ghent University, aims to unravel that mystery. The researchers focus on two factors that have received little attention in chemotherapy dosing: how your body is built and how active you are.
Not All Kilos Are Created Equal
So far, chemotherapy doses are calculated based on body surface area – a formula that only takes your height and weight into account. But two people with the same weight can have completely different body compositions. One may have more muscle mass, while the other carries more fat (Figure 2). And that can influence how the chemotherapy is absorbed, distributed, and broken down in the body. That’s why, in the PABTOX study, forty women with breast cancer who are treated with paclitaxel – a commonly used taxane-based chemotherapy drug – are being closely monitored. Advanced techniques like DXA scans measure their muscle and fat mass. They also wear activity trackers to monitor their daily physical activity. Through questionnaires and blood samples, the researchers assess how the treatment affects quality of life and how the drug behaves in the body.
Movement as an Ally
What makes this study truly innovative is that it also examines the effect of physical activity on the effectiveness and tolerability of chemotherapy. This emerging field is called exercise pharmacology. The central question is: Can movement help chemotherapy work better and be better tolerated? The researchers are developing a mathematical model (a so-called PK-PD model – see Figure 3) that predicts how paclitaxel behaves in the body – depending on a person’s muscle mass, fat percentage, and activity levels. This model could help identify who is at higher risk for side effects and who might benefit from an adjusted dose or a personalized exercise program.
Toward a More Personalized Approach
The ultimate goal? A more personalized cancer treatment, where dosing and care strategies are tailored to your weight and who you are. Suppose movement and body composition truly influence how well chemotherapy is tolerated. That opens the door to practical solutions – like exercise programs, dietary advice, or extra support during treatment. The PABTOX project is possible through funding by Kom op tegen Kanker (project ID: 13163). The findings could help improve cancer care in the future – with fewer side effects, better treatment adherence, and hopefully a higher quality of life for people with breast cancer.
More information: https://researchportal.vub.be/en/projects/interactions-between-pharmacokinetics-of-paclitaxel-physical-acti
Funding: Kom op tegen Kanker
RERE PI: Prof. dr. Nele Adriaenssens