Survival benefit when adding radiation therapy to hormone therapy for metastatic prostate cancer

The aim of this study was to examine the benefit of adding radiation therapy to androgen deprivation therapy (ADT) for metastatic prostate cancer. Researchers reported a significant survival advantage when radiation therapy was combined with ADT.

Metastatic prostate cancer is cancer that has spread from the prostate to distant organs. ADT is the first-line treatment for metastatic prostate cancer. Reducing androgen levels (male sex hormones such as testosterone) and their effect on cancer cell growth can dramatically improve survival. ADT can be combined with prostate surgery for a more intensive intervention. Studies have reported a survival benefit when the two treatments were combined.

Radiation therapy, such as external beam radiation therapy (EBRT), is commonly used in non-metastatic prostate cancer. EBRT involves directing high-energy rays at the tumor site to kill cancer cells. Whether adding radiation therapy to ADT is associated with a similar benefit for metastatic prostate cancer is still being investigated.  

This study aimed to examine the benefit of adding EBRT to ADT for metastatic prostate cancer.

The records of 6,382 men with metastatic prostate cancer were included in analysis. 91.6% of men were treated with ADT alone. 8.4% of men were treated with ADT and EBRT. The average time between diagnosis and start of EBRT was 101 days. Patients were followed for an average of 5.1 years.

Average overall survival (time from treatment until death from any cause) was 53 months for men treated with ADT and EBRT. This was significantly longer compared to 29 months with ADT alone. 5-year overall survival was 49% for ADT plus EBRT and 25% for ADT alone.

Overall, the addition of EBRT improved survival by 38%. This analysis accounted for age, ethnicity, additional medical conditions, tumor stage, insurance status, previous chemotherapy, and cancer markers in the blood and from tissue samples.

Researchers concluded that men with metastatic prostate cancer receiving EBRT with ADT lived significantly longer compared to ADT alone.

Studies that randomly assign patients to treatment groups are needed to confirm these results.