Assessment and management of bone health in women with early breast cancer receiving endocrine treatment in the DATA study

Int J Cancer. 2019 Sep 1;145(5):1325-1333. doi: 10.1002/ijc.32205. Epub 2019 Mar 4.


The phase III DATA study investigates the efficacy of adjuvant anastrozole (6 vs. 3 year) in postmenopausal women with breast cancer previously treated with 2-3 years of tamoxifen. This planned side-study assessed patterns of care regarding detection and treatment of osteopenia/osteoporosis, and trends in bone mineral density (BMD) during and after therapy. We registered all BMD measurements and bisphosphonate-use. Time to osteopenia/osteoporosis was analysed by Kaplan Meier methodology. For the trend in T-scores we used linear mixed models with random patients effects. Of 1860 eligible DATA patients, 910 (48.9%) had a baseline BMD measurement. Among patients with a normal baseline BMD (n = 417), osteopenia was observed in 53.5% and 55.4% in the 6- and 3-year group respectively (p = 0.18), during follow-up. Only two patients (3-year group) developed osteoporosis. Of the patients with osteopenia at baseline (n = 408), 24.4% and 20.4% developed osteoporosis respectively (p = 0.89). Three years after randomisation 18.3% and 18.2% used bisphosphonates in the 6- and 3-year groups respectively and 6 years after randomisation this was 23.7% and 20.9% respectively (p = 0.90) of which the majority used oral bisphosphonates. The yearly mean BMD-change during anastrozole in the lumbar spine showed a T-score decline of 0.075. After bisphosphonate addition the decline became less prominent (0.047 (p < 0.001)) and after anastrozole cessation, while continuing bisphosphonates, the mean BMD yearly increased (0.047 (p < 0.001)). In conclusion, extended anastrozole therapy was not associated with a higher incidence of osteoporosis. Anastrozole-use was associated with a BMD decrease; however, the decline was modest and partially reversible after anastrozole cessation.

Trial registration: NCT00301457.

Keywords: adjuvant; anastrozole; aromatase inhibitors; bone health; bone mineral density; breast cancer; endocrine therapy; osteopenia; osteoporosis; tamoxifen.

Publication types

  • Clinical Trial, Phase III
  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Anastrozole / administration & dosage*
  • Anastrozole / adverse effects
  • Antineoplastic Agents, Hormonal / administration & dosage
  • Antineoplastic Agents, Hormonal / adverse effects
  • Bone Density / drug effects
  • Breast Neoplasms / drug therapy*
  • Female
  • Fractures, Bone
  • Humans
  • Middle Aged
  • Osteoporosis, Postmenopausal / diagnosis*
  • Osteoporosis, Postmenopausal / therapy*
  • Prospective Studies
  • Tamoxifen / administration & dosage
  • Tamoxifen / adverse effects


  • Antineoplastic Agents, Hormonal
  • Tamoxifen
  • Anastrozole

Associated data