Evaluating the effects of various treatments on cognitive function in older men with resistant prostate cancer

This study aimed to investigate the link between various treatments for castration-resistant prostate cancer (CRPC) and cognitive (mental) dysfunction in older men. The main finding was that the treatments assessed did not appear to have an impact on cognitive function.

CRPC is prostate cancer that keeps growing despite treatments that reduce male sex hormones. There are many treatments used for CRPC such as docetaxel (Taxotere) chemotherapy, abiraterone acetate (AA; Zytiga), enzalutamide (Xtandi), and radium 223 dichloride (RA223; Xofigo). 

Cognitive function refers to an individual's perceptions, memory, thinking, reasoning, and awareness. Cancer treatments may have effects on cognitive function. In particular, older adults are at greater risk for experiencing cognitive dysfunction due to cancer treatments. Some treatments commonly used for CRPC  have been associated with cognitive decline. However, there is limited research available on this association. 

155 men aged 65 or older with metastatic (cancer has spread from the original location) CRPC were included in the study. Participants received docetaxel (51),  AA (29), enzalutamide (54), or RA223 (21) treatments. Cognitive function was measured before, and at the end of treatment.

Most patients did not appear to have any change in cognitive function during treatment or showed small improvements. No patient experienced a clinically significant (genuine and noticeable effect on daily life) cognitive decline.

Between 0% and 6.5% of patients experienced cognitive dysfunction following treatment. Patients treated with enzalutamide appeared to have greater cognitive dysfunction than those taking AA but these differences were not clinically significant. The only factor associated with cognitive decline was increasing age.

This study suggested that most older men with CRPC do not experience cognitive dysfunction following treatment, regardless of the treatment used.

This study only included a small number of men treated for CRPC in Canada. Therefore, the results may not apply to a larger patient population in the rest of the world.

If you have questions about the treatment of CRPC, please consult your doctor.