Patients receiving endocrine therapy for hormone-sensitive cancers, such as men with prostate cancer (MPC) on hormone ablation therapy (HAT) and women with breast cancer (WBC) on adjuvant aromatase inhibitor therapy (AAIT), have an increased risk of developing osteoporosis. The aim of this study was to compare the safety and effectiveness of denosumab (Prolia®) with selective estrogen receptor modulators (SERMs) (raloxifene and bazedoxifene), bisphosphonates (zoledronate, ibandronate, alendronate, and risedronate), and placebo for the treatment of osteoporosis in patients receiving endocrine therapy for hormone-sensitive cancer.

Systematic literature searches were conducted in three biomedical databases (PubMed, the Cochrane Library, and Embase) to identify randomized controlled trials (RCTs). Only RCTs that investigated MPC on HAT or WBC on AAIT allocated to denosumab, SERMs, bisphosphonates, or placebo were included. RCTs were appraised using the Cochrane Risk of Bias 2.0 tool. Frequentist network and pairwise meta-analyses were performed on predetermined outcomes of vertebral or nonvertebral fractures, treatment-related adverse events (AEs), bone mineral density (BMD), mortality, withdrawal due to treatment-related AEs, and serious AEs.

A total of 14 RCTs (15 publications, 6,463 participants) were included. Relative to placebo, denosumab was found to prevent vertebral fractures in cancer patients receiving endocrine therapy. Moreover, denosumab, alendronate, and zoledronate increased femoral neck (FN) and lumbar spine (LS) BMD in MPC on HAT, compared with placebo, whereas denosumab, risedronate, and ibandronate improved LS and total hip BMD in WBC on AAIT. Similarly, denosumab and risedronate increased trochanteric BMD in WBC on AAIT, compared with placebo. In WBC on AAIT, only denosumab increased FN BMD relative to placebo.

Denosumab was more effective than placebo in preventing vertebral fractures and improving BMD at the LS and FN in MPC on HAT, and in preventing vertebral fractures and improving FN, trochanteric, total hip, and LS BMD in WBC on AAIT. From a policy perspective, the continued reimbursement of denosumab needs to be reviewed.