Objectives: With novel antiandrogen treatments of varying clinical benefits and risks becoming available, this study investigates how patients with castration-resistant prostate cancer (CRPC) value differences in treatment characteristics.
Design: Cross-sectional observational study.
Setting: A discrete choice experiment was conducted. Patients chose between two hypothetical non-metastatic CRPC (nmCRPC) treatments defined by six attributes: risk of fatigue, falls or fracture, cognitive impairment, hypertension, rashes as side effects to treatment and extension of time until cancer-related pain occurs.
Participants: A total of 137 adult male patients with CRPC with no prior experience with chemotherapy and with Eastern Cooperative Oncology Group status 0-1 were recruited. Patients were excluded if they participated in an investigational programme outside of routine clinical practice, had a clinically relevant medical or psychiatric condition, or diagnosis of visceral/other metastases not related to the prostate, or were otherwise deemed ineligible by the referring physician.
Primary outcome measures: Relative preference weights and relative importance of the attributes was estimated by hierarchical Bayesian logistic regression.
Results: Among the treatment attributes, 'risk of cognitive impairment as a side effect of treatment' was the most important attribute (relative importance (RI) (95% CI): 27.47% (24.80% to 30.14%)), followed by 'extension of time until cancer-related pain occurs' (RI (95% CI): 17.87% (15.49% to 20.25%)) and the 'risk of falls or fracture' (RI (95% CI): 15.99% (14.73% to 17.25%)). The 'risk of hypertension as a side effect of treatment' (RI (95% CI): 13.77% (12.73% to 14.81%)) had similar RI as 'risk of rashes as a side effect of treatment' (RI (95% CI): 13.17% (12.15% to 14.19%)), followed by the 'risk of fatigue as a side effect of treatment' (RI (95% CI): 11.74% (10.75% to 12.73%)).
Conclusions: Patients consider the risk of cognitive impairment as a side effect of treatment as the most important attribute in nmCRPC, followed by the extension of time until cancer-related pain occurs, and the risk of falls and fracture. These features should be considered in treatment decision making for nmCRPC in Japan.
Keywords: adult oncology; prostate disease; urological tumours.
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