Bone fractures among postmenopausal patients with endocrine-responsive early breast cancer treated with 5 years of letrozole or tamoxifen in the BIG 1-98 trial

Manuela Rabaglio, Z. Sun, K. N. Price, M. Castiglione-Gertsch, H. Hawle, B. Thürlimann, H. Mouridsen, M. Campone, J. F. Forbes, R. J. Paridaens, M. Colleoni, T. Pienkowski, J. M. Nogaret, I. Láng, I. Smith, R. D. Gelber, A. Goldhirsch, A. S. Coates

Research output: Contribution to journalArticle

Abstract

Background: To compare the incidence and timing of bone fractures in postmenopausal women treated with 5 years of adjuvant tamoxifen or letrozole for endocrine-responsive early breast cancer in the Breast International Group (BIG) 1-98 trial. Methods: We evaluated 4895 patients allocated to 5 years of letrozole or tamoxifen in the BIG 1-98 trial who received at least some study medication (median follow-up 60.3 months). Bone fracture information (grade, cause, site) was collected every 6 months during trial treatment. Results: The incidence of bone fractures was higher among patients treated with letrozole [228 of 2448 women (9.3%)] versus tamoxifen [160 of 2447 women (6.5%)]. The wrist was the most common site of fracture in both treatment groups. Statistically significant risk factors for bone fractures during treatment included age, smoking history, osteoporosis at baseline, previous bone fracture, and previous hormone replacement therapy. Conclusions: Consistent with other trials comparing aromatase inhibitors to tamoxifen, letrozole was associated with an increase in bone fractures. Benefits of superior disease control associated with letrozole and lower incidence of fracture with tamoxifen should be considered with the risk profile for individual patients.

Original languageEnglish
Pages (from-to)1489-1498
Number of pages10
JournalAnnals of Oncology
Volume20
Issue number9
DOIs
Publication statusPublished - 2009

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Keywords

  • Aromatase inhibitor
  • Bone fracture
  • Hormonal therapy
  • Letrozole
  • Tamoxifen

ASJC Scopus subject areas

  • Oncology
  • Hematology

Cite this

Rabaglio, M., Sun, Z., Price, K. N., Castiglione-Gertsch, M., Hawle, H., Thürlimann, B., Mouridsen, H., Campone, M., Forbes, J. F., Paridaens, R. J., Colleoni, M., Pienkowski, T., Nogaret, J. M., Láng, I., Smith, I., Gelber, R. D., Goldhirsch, A., & Coates, A. S. (2009). Bone fractures among postmenopausal patients with endocrine-responsive early breast cancer treated with 5 years of letrozole or tamoxifen in the BIG 1-98 trial. Annals of Oncology, 20(9), 1489-1498. https://doi.org/10.1093/annonc/mdp033