Does age matter? Enzalutamide or bicalutamide for mestastatic castration-resistant prostate cancer patients of different ages

This study aimed to examine the effectiveness and safety of enzalutamide (Xtandi) compared to bicalutamide (Casodex) in castration-resistant metastatic prostate cancer (cancer that does not respond to hormone therapy) patients in different age groups. This study concluded that enzalutamide improved outcomes for patients compared to bicalutamide, regardless of age. 

Enzalutamide is an anti-androgen medication, which blocks hormone receptors in the body (such as testosterone). It is used for patients with prostate cancer spread outside of the pelvis, who have not had chemotherapy and who have not responded to previous treatments. Enzalutamide is associated with increasing time to disease progression compared to bicalutamide (another anti-androgen treatment). 

It is unclear if age has an impact on enzalutamide or bicalutamide treatment.

This study included 375 patients with castration-resistant metastatic prostate cancer. 184 patients were treated with enzalutamide. 191 patients were treated with bicalutamide. Patient data was analyzed into groups of older than 75 and younger than 75 years old. 

Enzalutamide reduced the risk of disease progression or death compared bicalutamide in patients both under (62%) and over (41%) 75 years. Side effects were similar between age groups. Patients over 75 treated with enzalutamide were more likely to have irregular heartbeats, urinary tract infection and decreased appetite. There was also more tiredness in enzalutamide patients of both age groups. Bicalutamide was associated with less back pain and hot flushes for those under 75. 

This study concluded that enzalutamide improved outcomes for patients compared to bicalutamide, regardless of age. 

Increased falls and cardiac issues are associated with enzalutamide in patients over 75.