Imagine fighting advanced breast cancer and regaining control through something as empowering as a workout routine – could exercise truly transform the lives of those with metastatic disease? New findings shared at the Advanced Breast Cancer Eighth International Consensus Conference (ABC8) reveal that supervised physical activity isn't just helpful; it can dramatically enhance muscle mass, strength, and overall stability in patients grappling with this severe form of the illness.
But here's where it gets controversial – is exercise being overlooked in cancer care, or should it be a non-negotiable part of every patient's journey? Let's dive into the details of this eye-opening research, which challenges long-held assumptions about what patients with late-stage cancer can achieve through movement.
The study, known as PREFERABLE-EFFECT, was led by Anne May, a Professor of Clinical Epidemiology of Cancer Survivorship at the University Medical Center (UMC) Utrecht and the Netherlands Cancer Institute. Presented at ABC8, it involved a nine-month structured program of aerobic exercises (like walking or cycling to build cardiovascular endurance), resistance training (such as weightlifting to build muscle power), and balance-focused activities. This wasn't just any exercise; it was supervised by trainers twice a week for the first six months, tapering to one supervised and one independent session per week in the final three months. All participants, whether in the exercise group or the standard care group, got an activity tracker and advice to aim for at least 30 minutes of daily physical activity.
To put this in context for beginners, metastatic breast cancer – often called stage IV – means the cancer has spread from the breast to other parts of the body, like bones or organs. This progression, combined with treatments such as chemotherapy or hormonal therapy, can sap energy, cause fatigue, nausea, and pain, and lead to muscle wasting (a condition where muscle mass decreases, weakening the body). In fact, low muscle mass in these patients is linked to worse side effects from treatments, like needing to reduce doses, and even poorer outcomes, including shorter survival. It's like the body's engine is running low on fuel, and inactivity only worsens the problem. Historically, people with metastatic cancer were often left out of exercise studies due to fears about their fragility, but this research flips the script.
And this is the part most people miss – the study proves exercise works even in advanced cases. The PREFERABLE-EFFECT trial was a large-scale, international randomized controlled trial, recruiting 357 patients from five European countries (Germany, Poland, Spain, Sweden, and The Netherlands) plus Australia between 2019 and 2022. Most participants were on first- or second-line treatments, and 74% had cancer that had metastasized to their bones, making falls and fractures a real risk. Half received standard medical care, while the other half participated in the supervised program.
Results after six months were striking: The exercise group showed significant improvements in physical performance, including better balance and stronger muscles, measured at both three and six months. Whole body lean mass – essentially, the total amount of muscle in the body – increased in the exercisers, whereas it declined in the control group. On average, the exercise participants had 0.79 kg more lean mass at three months and 0.32 kg more at six months compared to controls. Importantly, body fat percentage didn't change much between groups, meaning the gains were specifically in muscle, not just weight shifts.
Zooming in on arms and legs – the key movers for everyday tasks like walking or lifting – muscle mass in these areas jumped by an average of 0.6 kg at three months and 0.48 kg at six months in the exercise group versus controls. Even the skeletal muscle mass index (similar to BMI but focused on muscle density relative to height) improved, rising by 0.22 kg/m² at three months and 0.18 kg/m² at six months. For beginners, think of this as strengthening the body's core support system: Arms and legs handle movement and weight-bearing, so maintaining them prevents frailty, which is when muscles get so weak that simple tasks become hard or dangerous.
In contrast, the control group's arm and leg muscle mass and index dropped over the same period. Professor May highlighted how these improvements aren't just numbers: "Low muscle mass and strength often tie into balance issues, worsened by nerve damage from treatments, raising fall risks – especially critical for those with bone metastases prone to fractures."
To illustrate, she shared a compelling example: One participant struggled with balance so severely at the start that she couldn't board or exit a bus independently. After joining the supervised exercises, her stability improved, allowing her to travel to city centers and libraries again. It's stories like this that underscore how targeted movement can restore independence and joy in daily life.
Here's the controversial twist – while the benefits are clear, some might argue that pushing exercise on frail patients could add stress or be impractical. Yet, the research counters that supervised programs make it safe and effective. Professor May emphasized that lean mass boosts treatment tolerance, better prognosis (which is the likely course of the disease), and overall health, with stronger muscles linking to higher quality of life and lower mortality. This evidence supports integrating supervised exercise – especially with resistance components – into routine metastatic breast cancer care.
Building on this momentum, the ABC Global Alliance is set to launch a Physical Activity Resource Hub in early 2026. This free tool is tailored for people with advanced breast cancer, their caregivers, and healthcare professionals, offering videos, guides, and links to resources suitable for various metastasis sites (where the cancer has spread), symptoms, and fitness levels. Isabelle Aloi-Timeus, a cancer physiotherapist and founder of Salvati AC in Mexico City, stressed personalization: "As a cancer physiotherapist, I've witnessed exercise's profound benefits, but it must be supervised and tailored to ensure safety."
Eva Schumacher-Wulf, a metastatic breast cancer patient and editor-in-chief of the German magazine Mamma Mia!, added her perspective: "We know exercise matters for life quality and possibly survival, but advanced cancer patients need specialized programs that fit their realities – not one-size-fits-all advice."
In wrapping up, Professor Fatima Cardoso, a medical oncologist and President of the ABC Global Alliance, noted: "Managing advanced breast cancer requires balancing life quantity and quality. Beyond new treatments, we must research ways to enhance patients' well-being. Professor May's work empowers patients by showing how smart exercise can improve their quality of life and give them back some control over their condition."
What do you think – should supervised exercise be standard for metastatic breast cancer patients, or are there barriers we've overlooked? Do you agree this could change outcomes, or does it spark concerns about overexertion in vulnerable groups? Share your thoughts in the comments – let's discuss!
