Impact of treatment on elder-relevant physical function and quality of life outcomes in older adults with metastatic castration-resistant prostate cancer

Introduction: Understanding physical function (PF) and quality of life (QoL) treatment effects are important in treatment decision-making for older adults with cancer. However, data are limited for older men with metastatic castration-resistant prostate cancer (mCRPC). We evaluated the effects of treatment on PF and QoL in older men with mCRPC.

Materials and methods: Men aged 65+ with mCRPC were enrolled in this multicenter prospective observational study. PF measures included instrumental activities of daily living, grip strength, chair stands, and gait speed. QoL measures included fatigue, pain, mood, and Functional Assessment of Cancer Therapy (FACT)-General total and sub-scale scores. Outcomes were collected at baseline, three, and six months. Linear mixed effects regression models were used to examine PF and QoL differences over time across various treatment cohorts.

Results: We enrolled 198 men starting chemotherapy (n = 71), abiraterone (n = 37), enzalutamide (n = 67), or radium-223 (n = 23). At baseline, men starting chemotherapy had worse measures of PF, QoL, pain, and mood than the other groups. Over time, all PF measures remained stable, pain improved, but functional wellbeing (FWB) and mood worsened significantly for all cohorts. However, change over time in all outcomes was not appreciably different between treatment cohorts. Worst-case sensitivity analyses identified attrition (ranging from 22 to 42% by six months) as a major limitation of our study, particularly for the radium-223 cohort.

Discussion: FWB and mood were most prone to deterioration over time, whereas pain improved with treatment. Although patients initiating chemotherapy had worse baseline PF and QoL, chemotherapy was not associated with significantly greater worsening over time compared to other common therapies for mCRPC. These findings may assist in treatment discussions with patients. However, given the modest sample size, attrition, and timeframe of follow-up, the impact of treatment on PF and QoL outcomes in this setting requires further study, particularly for radium-223.