Falls and fractures in men with prostate cancer taking second-generation androgen receptor antagonists: A retrospective chart review.

Introduction: Second-generation androgen receptor antagonists, including enzalutamide, apalutamide, and darolutamide, are commonly used to treat metastatic and non-metastatic prostate cancer. Although these medications are typically well-tolerated, falls were reported in 4.2-15.6% of patients and fractures in 4.2-11.7% of patients enrolled in the phase III clinical trials evaluating these drugs in prostate cancer. However, post-marketing studies have reported a lower incidence than reported in clinical trials. The objective of this study is to determine the prevalence of falls and fractures in patients with prostate cancer receiving second-generation androgen receptor antagonists at UConn Health and identify potential risk factors associated with falls and fractures in these patients.

Methods: A retrospective chart review involving patients with prostate cancer treated with darolutamide, enzalutamide, or apalutamide from March 1, 2022, to March 31, 2023, at UConn Health Carole & Ray Neag Comprehensive Cancer Center. Data recorded includes basic demographics, history of fall or fracture, presence of metastases, fall risk, history of osteoporosis, prescribed second-generation androgen receptor antagonist, and other comorbidities. Data was evaluated using descriptive statistics.

Results: Twenty-six men were included, all of whom were receiving enzalutamide. At baseline, 96.1% of patients had bone metastases, 15.4% had osteoporosis, 15.4% had osteopenia, and 34.6% had neuropathy. The incidence of falls was 19.2% and the incidence of fractures was 26.9%. The mean length of therapy at time of a fall was 19.44 months (range, 6-31 months). The mean length of therapy at time of a fracture was 19 months (range, 1-33 months). In patients experiencing fall, 100% had arthralgia, 60% had neuropathy, 40% had a gait problem, 40% had hypertension, and 80% of them were at risk of fall. In patients experiencing fracture, 28.6% had osteoporosis, 42.9% had osteopenia, 100% had bone metastases, and 57.1% were on denosumab at time of fracture.

Conclusion: The prevalence of falls and fractures in patients receiving enzalutamide were higher in this retrospective chart review than reported in clinical trials and post-marketing studies. This could be due to the small patient population or the patient's comorbidities such as osteoporosis, bone metastases, or neuropathy. Fall/fracture risk with enzalutamide and other risk factors for fall and fracture should be considered when discussing treatment and developing a monitoring plan.