Androgen deprivation therapy (ADT) is the effective treating prostate cancer but is often accompanied by cancer treatment-induced bone loss (CTIBL), which impairs the patient's quality of life. In patients with nonmetastatic castration-sensitive prostate cancer (M0CSPC) who already have osteoporosis before starting ADT, appropriate bone-modifying agent intervention must be performed in parallel, as the patient has a high risk of future fracture.
However, little is known about therapeutic interventions aimed at preventing the progression of CTIBL and new fractures. The present study explored the effect of once-yearly zoledronic acid 5 mg (ZOL 5 mg) on bone mineral density (BMD) and new vertebral fractures (VFs) in M0CSPC patients with coexisting osteoporosis before starting ADT.
We conducted a retrospective, multi-institutional, cohort study involving 42 M0CSPC patients with osteoporosis who had undergone ADT with/without a single intravenous infusion of ZOL 5 mg at the start of ADT (ZOL 5 mg group, n = 26; control group, n = 16). The association of the ZOL 5 mg with changes in the BMD from baseline to 12 months and the incidence of VFs were evaluated.
Prevalent VFs were found in 47.6% of all patients at baseline. ZOL 5 mg significantly increased the lumbar spine BMD (LS-BMD) (mean rate of change: + 4.02%, p < 0.0001) and significantly decreased the TRACP-5b (mean rate of change: - 52.1%, p < 0.0001) at 12 months after starting ADT. Incident VFs were identified in 19.0% of all patients at 12 months after starting ADT. After adjusting for the age, BMI, and changes in the LS-BMD, ZOL 5 mg was not significantly associated with incident VFs (odds ratio 0.66, 95% confidence interval 0.04-11.3, p = 0.7774).
ZOL 5 mg significantly increased the LS-BMD 12 months after starting ADT, and our short-term results showed that ZOL 5 mg was not significantly correlated with the suppression of incident vertebral fractures.
BMC cancer. 2021 Apr 17*** epublish ***
Daisuke Watanabe, Takahiro Kimura, Ken Watanabe, Hiromitsu Takano, Yuko Uehara, Tadaaki Minowa, Akemi Yamashita, Seiichiro Yoshikawa, Akio Mizushima
Department of Palliative Medicine, Juntendo University Graduate School of Medicine, 2-1-1 Hongo, Bunkyo-ku, Tokyo, 113-8421, Japan. ., Department of Urology, The Jikei University School of Medicine, Tokyo, Japan., Department of Radiology, The Jikei University School of Medicine, Tokyo, Japan., Department of Orthopedic Surgery, Koto Hospital, Tokyo, Japan., Department of Palliative Medicine, Juntendo University Graduate School of Medicine, 2-1-1 Hongo, Bunkyo-ku, Tokyo, 113-8421, Japan., Department of Urology, Koto Hospital, Tokyo, Japan., Cancer Therapeutic Center, Juntendo University Urayasu Hospital, Chiba, Japan.