Alendronate Reduces the Risk of Bone Metastases in Osteoporotic Women with Early Breast Cancer

Presentation Number: LB SUN 45
Date of Presentation: April 2nd, 2017

Vanessa Rouach*1, Inbal Goldshtein2, Ido Wolf3, Raphael Catane4, Gabriel Chodick5, Naftali Stern6 and Daniel Cohen7
1tel aviv sourasky medical center, tel aviv, Israel, 2Maccabi Healthcare Services, 3Tel Aviv University, Tel Aviv, Israel, 4Sheba Medical Center, institute of oncology,, 5Maccabi Healthcare Services, epidemiology and database research,, 6Tel Aviv Sourasky Medical Center and Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel, 7School of Public Health and Stanley Steyer Institute for Cancer Epidemiology and Research, Tel Aviv University

Abstract

Background: Bisphosphonates (BP) are widely used in osteoporosis treatment. By reducing the production of osteolysis-derived growth factors, BP may render the bone microenvironment unsupportive of tumor cell survival thereby reducing breast cancer recurrence. Recent data on the association between oral bisphosphonates and disease outcomes in patients with breast cancer are scarce, and to the best of our knowledge, there are no data available on Alendronate, the most common oral agent for the treatment of post-menopausal osteoporosis.

Aim: To examine the association between previous oral bisphosphonate exposure and the incidence of bone metastases in osteoporotic women diagnosed with early breast cancer.

Subjects and methods: This historical cohort study was conducted at the oncologic clinic at Tel Aviv Souraski Medical Center. The study population included postmenopausal women with early breast cancer, diagnosed between January 1st 2002 and December 31st 2012. We reviewed medical files to collect data on cancer characteristics, diagnosis of osteoporosis, prior bisphosphonate exposure and outcome. The study protocol was approved by the Institutional Review Board of Tel Aviv Souraski Medical Center.

Results: Among the 297 osteoporotic women were identified, 145 (49%) were treated with bisphosphonates (mostly Alendronate) before cancer diagnosis. BP-treated women were older than the naïve ones (67.9 vs 64.6, p=0.013). No significant differences were noted regarding BMI, smoking status, parity or socioeconomic status. Cancer characteristics were similar between the two groups including tumor grade, positive lymph nodes and hormonal receptor status.

A Cox proportional hazards survival model adjusted for age at diagnosis, BMI, smoking status, breast cancer family history, HRT use, and tumor grade showed that previous exposure to oral bisphosphonates significantly reduced the incidence of bone metastases: HR=0.009 CI (0.004-0.403) p<0.002 

Conclusions: Alendronate, the most widely prescribed oral bisphosphonate for the treatment of osteoporosis, is associated with a lower likelihood for bone metastases in postmenopausal women with early breast cancer. Women at risk may benefit from early oral bisphosphonate treatment.


 

Nothing to Disclose: VR, IG, IW, RC, GC, NS, DC