New insights on exercise and weight in breast cancer survivors
Breast cancer survivors are navigating more than cancer treatment. A growing body of research suggests that exercise can play a crucial role in weight management for women undergoing long-term estrogen-blocking therapy, a common part of treatment plans. A recent study from the University of British Columbia (UBC) Okanagan, led by Dr. Sarah Purcell, sheds light on how physical activity might influence appetite and body composition in this specific group.
Why weight management matters for survivors
Even when breast cancer patients survive the disease, weight gain during and after endocrine therapy can pose serious health risks. Obesity increases the likelihood of heart disease and type 2 diabetes and may, in some cases, contribute to cancer recurrence. Dr. Purcell notes that while survival rates are generally favorable, weight control remains a pressing concern for clinicians and researchers alike. The challenge is to understand why this weight gain occurs and how lifestyle interventions, like exercise, can mitigate it.
The hormonal context: estrogen suppression and appetite
Endocrine therapy often lowers estrogen levels for extended periods, which can disrupt normal metabolic processes. The exact mechanisms behind treatment-related weight gain are not fully understood, but reduced estrogen exposure is believed to be a contributing factor. The question the study sought to answer was whether structured physical activity could influence weight by altering appetite signals in this group.
What the study found: exercise and the appetite hormone PYY
The researchers compared two randomized trials involving female breast cancer survivors and adults with obesity. All participants were premenopausal at diagnosis and currently on endocrine therapy. The surprising finding was that exercise appeared to raise levels of Peptide YY (PYY), a hormone that suppresses appetite, among breast cancer survivors on estrogen-blocking therapy. This response was observed immediately after exercise and lasted longer than expected in this group.
Dr. Purcell explains that while many survivors did not report feeling less hungry, their body’s hormonal signals pointed toward a stronger appetite-suppressing effect post-exercise. In practical terms, this could mean survivors might eat less relative to their body size after workouts, contributing to better weight management over time. The findings suggest a novel interaction between exercise and estrogen suppression that has not been seen in non-cancer populations.
Why this matters for exercise recommendations
The study reinforces existing guidelines that advocate for both aerobic activity and resistance training to improve body composition and metabolic health in breast cancer survivors. For individuals dealing with obesity, these types of exercise are especially important because they support heart health and help maintain muscle mass during treatment. Beyond immediate fitness benefits, exercise may influence long-term weight trajectories by modulating hormones related to appetite.
Implications for survivors and clinicians
These results are encouraging for survivors and the clinicians who guide their care. If exercise can help regulate appetite through PYY and other hormones, it adds a practical, non-pharmacological tool to support weight management during long-term endocrine therapy. It also opens avenues for personalized exercise prescriptions that consider a survivor’s hormonal treatment, body composition, and metabolic health.
Looking ahead
Dr. Purcell emphasizes the need for further research to confirm these findings across diverse populations and to explore the mechanisms in greater depth. Future studies may help tailor exercise programs to maximize hormonal benefits while ensuring safety and tolerability for all survivors. For now, the message is clear: regular physical activity offers tangible benefits for weight management and overall health for breast cancer survivors navigating estrogen-blocking therapy.
