Effect of Tamoxifen on the Risk of Osteoporosis and Osteoporotic Fracture in Younger Breast Cancer Survivors: A Nationwide Study

Jihyoun Lee; Heba M Alqudaihi; Michael Seungcheol Kang; Jisun Kim; Jong Won Lee; Beom Seok Ko; Byung Ho Son; Sei Hyun Ahn; Jong Eun Lee; Sun Wook Han; Zisun Kim; Sung Mo Hur; Ji Sung Lee; Il Yong Chung

doi:10.3389/fonc.2020.00366

Effect of Tamoxifen on the Risk of Osteoporosis and Osteoporotic Fracture in Younger Breast Cancer Survivors: A Nationwide Study

Front Oncol. 2020 Mar 20:10:366. doi: 10.3389/fonc.2020.00366. eCollection 2020.

Authors

Jihyoun Lee¹, Heba M Alqudaihi^{2

3}, Michael Seungcheol Kang⁴, Jisun Kim³, Jong Won Lee³, Beom Seok Ko³, Byung Ho Son³, Sei Hyun Ahn³, Jong Eun Lee⁵, Sun Wook Han⁵, Zisun Kim⁶, Sung Mo Hur⁶, Ji Sung Lee^{7

8}, Il Yong Chung³

Affiliations

¹ Department of Surgery, Soonchunhyang University Seoul Hospital, Seoul, South Korea.
² Department of Surgery, Qatif Central Hospital, Ministry of Health, Al Qatif, Saudi Arabia.
³ Department of Surgery, Asan Medical Center, University of Ulsan College of Medicine, Seoul, South Korea.
⁴ Department of Orthopedic Surgery, Asan Medical Center, University of Ulsan College of Medicine, Seoul, South Korea.
⁵ Department of Surgery, Soonchunhyang University Cheonan Hospital, Cheonan, South Korea.
⁶ Department of Surgery, Soonchunhyang University Bucheon Hospital, Bucheon, South Korea.
⁷ Clinical Research Center, Asan Institute for Life Sciences, Asan Medical Center, University of Ulsan College of Medicine, Seoul, South Korea.
⁸ Department of Clinical Epidemiology and Biostatistics, Asan Medical Center, University of Ulsan College of Medicine, Seoul, South Korea.

Abstract

Background: Although international guidelines recommend bone screening for premenopausal breast cancer patients taking adjuvant tamoxifen, the effects of tamoxifen on osteoporosis and related risks remain controversial. The objective of this study was to investigate the incidence of and risk factors for osteoporosis and osteoporotic fractures in younger breast cancer patients. Methods: A nationwide retrospective cohort study was conducted using South Korea Health Insurance Review and Assessment Service claims data. The rates of osteoporosis and osteoporotic fracture were calculated as incident cases per person-year and disease-free probability rates were analyzed with the Kaplan-Meier method. To identify risk factors for osteoporosis and osteoporotic fracture, a multivariable Cox proportional hazard regression model was applied. Results: From January 2009 to December 2014, a total of 47,649 breast cancer patients were included. The incidence rates of osteoporosis and osteoporotic fracture were 23.59 and 2.40 per 1,000 person-years, respectively. In the overall population, tamoxifen was significantly associated with a decreased risk of osteoporosis and osteoporotic fractures 0.76). However, tamoxifen was not associated with the risk of osteoporosis (HR 1.24, CI 0.85-1.82) and osteoporotic fracture (HR 8.15, CI 0.36-186.70) in patients under age 40. In the 40-49 years subgroup, tamoxifen significantly decreased the risk of osteoporosis (HR 0.74, CI 0.65-0.84) and osteoporotic fracture (HR 0.49, CI 0.31-0.76). Conclusions: Tamoxifen is not associated with an increased risk of osteoporosis and osteoporotic fracture in premenopausal breast cancer patients. Tailored screening strategies for breast cancer survivors with different osteoporosis risks are needed. Precis: Tamoxifen is not associated with an increased risk of osteoporosis and osteoporotic fracture in premenopausal breast cancer patients. Tailored screening strategies for breast cancer survivors who are at different risks of developing osteoporosis are needed.

Keywords: bone fractures; breast neoplasms; osteoporosis; survivorship; tamoxifen.