Bone health in women with breast cancer

Abstract

Women with early, estrogen receptor-positive breast cancer are treated with adjuvant endocrine therapy, using aromatase inhibitors or selective estradiol receptor modulators such as tamoxifen, to deprive breast tissue from the deleterious effects of estradiol action, hence improving long-term prognosis. Aromatase inhibitors and, in premenopausal women, tamoxifen accelerate bone loss and increase fracture risk. Therefore, all women commencing endocrine therapy need a targeted work-up to assess the baseline fracture risk, and monitoring of bone health during endocrine therapy should be individualized based on this baseline risk. While high-level evidence specific to early breast cancer is lacking, non-pharmacologic measures to maintain optimal bone health such as weight-bearing exercise and calcium and vitamin D sufficiency should be implemented in all women. Antiresorptive treatment should be initiated in all women with preexisting fragility fractures (including vertebral morphometric fractures) and should be considered in women with areal bone mineral density (BMD) T-scores < −2.0 (or Z-scores in women aged <50 years) or those experiencing rapid bone loss (≥5% per year), taking into consideration the baseline BMD and other risk factors for fracture. Further clinical trial evidence is required to provide definitive guidance regarding criteria to initiate antiresorptive treatment, choice of agents, and duration of treatment, taking into account potential oncologic benefits of antiresorptive therapy on breast cancer-related outcomes.

摘要

早期雌激素受体阳性的乳腺癌患者接受辅助内分泌治疗, 应用芳香化酶抑制剂或选择性雌二醇受体调节剂（如他莫西芬）, 使乳腺组织免受雌二醇作用的不利影响, 从而改善长期预后。芳香化酶抑制剂和绝经前妇女用的他莫西芬可加速骨质流失, 增加骨折风险。因此, 所有开始内分泌治疗的女性都需要有针对性的病情检查工作来评估基线骨折风险, 在内分泌治疗过程中应根据这一基线风险来进行个体化的骨骼健康监测。虽然缺乏针对早期乳腺癌的高水平证据, 但应在所有妇女中实施非药物治疗措施, 以保持最佳骨骼健康, 如负重锻炼和钙、维生素D的补充。先前有脆性骨折史的所有妇女（包括椎体形态骨折）都应开始骨吸收抑制剂治疗, 区域骨密度（BMD）T-scores <－2.0（或Z-scores在年龄<50岁）或那些经历快速骨质流失（每年≥5%）的妇女也应考虑应用骨吸收抑制剂治疗, 同时应考虑基线BMD水平及其它骨折风险。考虑到骨吸收抑制剂治疗对乳腺癌相关结局的潜在肿瘤益处, 未来需要提供进一步的临床试验证据来明确相关的治疗指导, 包括开始进行骨吸收抑制剂治疗的标准、药物的选择和治疗时间。

Keywords:

• Bone density
• breast cancer
• estradiol deprivation
• fracture

Potential conflict of interest

M. Grossmann has received speaker honoraria and conference support from Besins and Amgen Australia, has been an advisory board member for Otsuka, and has received research support from Bayer, Novartis, Weight Watchers, and Eli Lilly. S. K. Ramchand has received speaker honorarium from Counterpart (breast cancer support organization). Y.-M. Cheung has nothing to disclose.

Source of funding

Nil.