Understanding the biology of volumetric muscle loss for an individualized exercise rehabilitation approach in breast cancer patients.

Muscle maintenance relies on a multidimensional biologic balance that is extremely delicate in breast cancer patients, particularly those with advanced-stage disease. The biology that underpins breast cancer tumorigenesis, tumor progression and response to pharmacotherapies can modify muscle homeostasis, resulting in volumetric muscle loss. This condition dramatically increases the overall patients' frailty, leading to reduced survival and impaired quality of life. Physical activity may potentially improve muscle health in these patients, providing that an optimal patients selection is performed. The understanding of volumetric muscle loss biology in breast cancer survivors, coupled with focused clinical studies, would allow for the implementation of individualized rehabilitation protocols.