Adverse bone effects during pharmacological breast cancer therapy

The improved survival and cure rate of breast cancer patients leads to increased diagnosis of later occurring side effects to therapy such as osteoporosis. Conventional chemotherapies such as CMF and CEF are known to induce premature menopause, which increases bone loss but these therapies have additional detrimental effects on bone. The loss in bone mass during chemotherapy is substantial and may lead to increased fracture risk. The influence of taxanes on bone is less well known. Whereas tamoxifen has a slight protective effect on bone loss the opposite is true for aromatase inhibitors. Adverse effect reportings show, that adjuvant treatment with aromatase inhibitors in postmenopausal women increases the risk of clinical fractures as compared to tamoxifen. The Danish Bone Society suggests that all women with operable breast cancer have their fracture risk evaluated including a BMD measurement prior to initiation of adjuvant aromatase inhibitor therapy as a part of the standard examination program. If osteoporosis is diagnosed, anti-osteoporosis therapies should be considered. Moreover, all women undergoing adjuvant chemotherapy and endocrine therapy should be informed of the risk of bone loss and should receive life style advice of how to preserve bone. Adjuvant regimens in breast cancer patients improve survival and cure rates. Therefore it is preferable to use such therapies although they increase risk of side effects such as osteoporosis.