Can high-risk prostate cancer be treated with high-dose-rate brachytherapy, external beam radiotherapy plus long-term androgen deprivation therapy?

This study looked at whether the use of high-dose (HD) brachytherapy (BT) and hypofractionated external beam radiotherapy (EBRT) plus androgen-deprivation therapy (ADT) as a means of treatment for very high-risk prostate cancer (PCa). The study found that this treatment had significant benefits for patients with high-risk PCa. 

PCa is the most common organ tumor in men and is the second leading cause of cancer death in the USA. ADT is the standard care for PCa. ADT is a hormonal treatment used to lower the production of androgen (male sex hormones such as testosterone). ADT can have serious side effects such as osteoporosis (loss of bone density) and loss of muscle mass. 

EBRT and BT are radiotherapies. EBRT delivers radiation to the tumor from outside the body. BT involves the use of implants (seeds) into the tumor to release radiation. BT is associated with greater sparing of normal surrounding tissues when compared to EBRT. PCa can be complicated to treat when it metastasized (spreads to distant organs or tissues). Thes patients are considered very high-risk. Whether EBRT combined with HD-BT and long-term ADT can benefit patients with very high-risk PCa is still under investigation.

This study included 66 patients with very high-risk PCa. All patients received 6 months of ADT, followed by 2 fractions of HD-BT and 13 fractions of EBRT. ADT was continued for up to 3 years. Patients were followed up for an average of 53 months after finishing radiotherapy.  

PSA is a blood marker of PCa. If PSA levels rise after treatment, this is called biochemical failure (BF). At 5 years, 88.7% of patients were free from BF. 89.2% of patients did not have distant metastasis at 5 years and 97% of patients were alive after 5 years.

Medium severity side effects related to the urinary and genital organs in the short-term were seen in 6.1% of patients and long-term effects in 18.1%. 4.5% of patients experienced bowel-related side effects in the short-term, while no long-term bowel side effects were seen.

The authors concluded that the use of HD-BT and EBRT plus long-term ADT resulted in positive outcomes for patients with very high-risk PCa.

The study involved Japanese patients. Therefore, this study may not be applicable to the general population. Further studies including other populations are needed.