Evaluating combination therapies for metastatic hormone-sensitive prostate cancer.

This study was carried out to look at the use of combining radiotherapy (RT), systemic therapy (ST; whole-body treatment), and androgen deprivation therapy (ADT) for prostate cancer (PC) that is hormone-sensitive and has spread. The authors concluded that ADT plus RT led to better outcomes in patients with low-volume disease.

PC is the most common organ tumor in men and is the second leading cause of cancer death in the US. Hormone-sensitive PC can be treated using ADT. ADT is the standard care for PC. It is a hormonal treatment used to lower the production of androgens (male sex hormones such as testosterone). 

RT uses high dose radiation to kill cancer cells. STs are drugs that are given that spread around the body to kill cancer cells. Recent studies have evaluated different combinations of treatments for metastatic hormone-sensitive PC (mHSPC). However, the optimal treatment combination for these patients is yet to be determined. 

The study analyzed 10 trials that had 11914 patients overall. These trials compared different treatment combinations for mHSPC. ADT alone was compared to ADT + RT, ADT and STs such as apalutamide (APA; Erleada), enzalutamide (ENZ; Xtandi), docetaxel (DOC; Taxotere), abiraterone acetate + prednisone (AAP; Zytiga).

ADT + RT was better than ADT alone for improving overall survival. The use of combined STs + ADT was significantly better to ADT-only and to ADT + RT. The most effective ST used in combination with ADT was ENZ. This increased overall survival by 47% when compared to an ADT-only regimen.

ADT combined with STs or RT also improved survival without cancer worsening compared to ADT alone. The highest benefit in survival without cancer worsening (by 74%) was seen with ADT + APA. ADT + ST combinations also improved pain progression when compared to ADT alone.

The authors found that ADT combined with RT or STs was more effective compared to ADT alone in the treatment of patients with mHSPC. 

The trials used for this study had varying RT treatment regimens. Several trials had lower dose RT given to patients instead of the standard dose.