Should men with castration-resistant metastatic prostate cancer receive further hormone therapy?

This study aimed to discover the optimal timing of hormone therapies in combination with androgen-deprivation therapy (ADT) for patients with metastatic hormone-sensitive prostate cancer. This study found that treatment with a second hormone therapy after prostate cancer becomes immune to hormone treatment is associated with longer overall survival.

A main treatment option for prostate cancer is androgen deprivation therapy (ADT). This blocks the male hormones, such as testosterone, responsible for cancer growth. Docetaxel (Taxotere) is a chemotherapy drug which can be used to increase overall survival for patients with metastatic prostate cancer. Androgen deprivation therapy plus docetaxel increases overall survival in men with large, advanced prostate cancer that responds to hormone treatment. Most patients will have a positive result with this treatment but over time can become resistant to this treatment.

The optimal timing of the androgen deprivation therapy plus docetaxel is unclear. 

This study aimed to evaluate the time taken for prostate cancer to become resistant to hormone therapy and what medication was used once that happened. 136 patient files were included in this study.

It took an average of 19.6 months for prostate cancer to become resistant to hormone therapies. 44% of patients received more than one treatment. 48 patients in total were given a more recent version of hormone therapy, such as abiraterone acetate (Zytiga) or enzalutamide (Xtandi). Other treatments that were used included radium-223, chemotherapy or a targeted therapy (Sipuleucel–T). 

Use of another hormone therapy was associated with a greater period of time before the cancer progressed (9 months compared to 3 months for those on the other medications). A longer overall survival time was associated with a longer time before the prostate cancer becomes resistant to hormone therapy. 

This study found that treatment with a second hormone therapy after prostate cancer becomes resistant to hormone treatment is associated with longer overall survival.

Several of this study's conclusions were not statistically significant.