Energy balance in advanced breast cancer: extending beyond the curative setting.

Outcomes in early-stage breast cancer, including quality of life, body composition, physical functioning, physiologic biomarkers, cancer recurrence, and mortality, are associated with body weight, diet, and physical activity. These same endpoints may also be relevant in patients with metastatic breast cancer; however, few studies have evaluated the role of energy balance in this setting. Future work is needed to determine how body weight, nutrition, and exercise or other physical activity might affect the disease course of metastatic breast cancer, and whether energy balance may be a component of beneficial supportive or therapeutic interventions for specific patient populations living with metastatic breast cancer.