What are the most effective exercise, physical activity and dietary interventions to improve body composition in women diagnosed with or at high-risk of breast cancer? A systematic review and network meta-analysis.

BACKGROUND: Obesity has been recognized as a risk factor in the development and recurrence of breast cancer and is also associated with poor prognostic outcomes. This systematic review and network meta-analysis aimed to identify the most effective exercise, physical activity, and dietary interventions to reduce fat mass, body fat percentage and body weight as well as potentially increase lean mass in women diagnosed with or at high risk of breast cancer. METHODS: A systematic search of databases was performed up to May 2022. Eligible randomized controlled trials examined the effects of exercise, physical activity and/or dietary interventions on fat mass and lean mass in women diagnosed with or at high risk of breast cancer. A random-effects network meta-analysis was conducted to determine the effects of different interventions across outcomes when sufficient studies were available. RESULTS: Eighty-four studies (n = 6428) were included in this review. Caloric restriction and combined exercise + caloric restriction significantly reduced fat mass (range, -3.9 to -3.7 kg) and body weight (range, -5.3 to -4.7 kg), whereas physical activity + caloric restriction significantly reduced body fat percentage (-2.4%; 95% confidence interval [CI], -3.4% to -13%) and body mass index (-2.2 kg × m-2 ; 95% CI, -3.0 to -1.4 kg × m-2 ) in breast cancer patients. Resistance exercise was the most effective intervention to increase lean mass (0.7 kg; 95% CI, 0.5-1.0 kg) in breast cancer patients. CONCLUSION: Multimodal exercise and diet programs were the most effective interventions to reduce fat mass, body fat percentage, and body weight and increase and/or preserve lean mass.

Exercise medicine considerations for pregnancy-associated breast cancer: Characteristics, prognosis and treatment.

Breast cancer is the most prevalent cancer in women worldwide and is the most common cancer diagnosis made during pregnancy or in the postpartum period. When breast cancer is diagnosed either during pregnancy or in the first-year postpartum, it is referred to as pregnancy-associated breast cancer. The aim of this review is to assess existing literature regarding the recommendations and outcomes of participating in exercise for people with pregnancy-associated breast cancer. The occurrence of pregnancy-associated breast cancer is increasing as a growing number of women delay first pregnancies. Women undergoing treatment for pregnancy-associated breast cancer are dealing with both cancer and its treatment as well as a pregnancy or postpartum period, and often encounter symptoms associated with cancer diagnosis and treatment, such as nausea, pain and fatigue while simultaneously navigating a pregnancy or early motherhood. These experiences can be barriers to participating in exercise, despite exercise being associated with numerous benefits for both pregnancy health and breast cancer outcomes. Numerous studies report the benefits of exercising during breast cancer treatment in ameliorating associated symptoms, and some studies report that engaging in exercise can lead to healthier and lower risk pregnancies. However, there is a lack of consensus around appropriate exercise programmes for this specific population. Given the associated benefits of participating in exercise for both breast cancer patients and pregnant/postpartum women as separate groups, research into exercise medicine designed specifically for the pregnancy-associated breast cancer population is needed.