Musculoskeletal events associated with the management of endocrine-responsive breast cancer

Musculoskeletal symptoms have been reported in patients treated with third generation aromatase inhibitors (AIs) and with blockers of hypothalamic- pituitary gonadal axis. AIs act by suppressing postmenopausal estrogen biosynthesis through inhibition of the enzyme aromatase, which is responsible for the conversion of androgens to estrogens in many tissues. Maximal estrogen and/or androgen deprivation is beneficial for cancer growth suppression but could be associated with side effects such as accelerated bone loss and osteoporotic fractures which are extensively reported. Musculoskeletal events, another group of adverse events, have been studied to a lesser extent and are usually commonly reported as arthralgia and myalgia. Furthermore, the pathogenesis and anatomical findings of musculoskeletal symptoms have not been adequately elucidated. In this communication, we review recent information related to musculoskeletal symptoms in breast cancer and speculate on possible explanations for musculoskeletal pain related to hormone deprivation. We outline treatment options for control of arthralgia and myalgia due to hormonal therapy. More knowledge about the etiology and management of musculoskeletal adverse effects breast cancer during endocrine therapy is needed because discontinuation of the treatment due to intolerant symptomatology may result in disruption of the treatment schedule.