The role of androgen deprivation therapy plus radiotherapy in the treatment of prostate cancer after prostate surgery

This study compared the safety and effectiveness of short-term androgen deprivation therapy (ADT) combined with radiotherapy (RT) in patients who underwent radical prostatectomy (RP). The main finding was that the combination of ADT and RT reduced the risk of recurrence and disease progression in these patients.

RP is surgery to remove the prostate gland and the surrounding tissues in patients with prostate cancer. Patients can also receive RT after RP, to prevent relapse (return of cancer). However, only half of these patients do not experience relapse within 5 years of treatment. Patients whose cancer has spread to the neighboring organs generally receive ADT. ADT is a hormonal therapy that stops the growth of prostate cancer cells. However, the role of ADT combined with RT after RP is still unknown.

The study included a total of 743 men with prostate cancer who underwent RT. Their prostate-specific antigen (PSA; a prostate cancer marker in the blood) levels increased from 0.1-0.2 ng/mL to 2.0 ng/mL after RP. The increase in PSA levels over time is an indicator of the prostate cancer’s progression. 374 patients received RT alone and 369 patients were given RT combined with 6 months of ADT as a salvage treatment. Salvage treatment is given as a rescue therapy when other treatments fail. Goserelin (Zoladex) was used as ADT. Patients were followed up for 112 months on average.

The percentage of patients who were alive without signs of cancer progression at 120 months was 64% in the combination group and 49% in the RT alone group. In patients treated with RT and ADT, the risk of cancer progression was 46% lower compared to RT alone.

At 120 months, the risk of survival without cancer spreading to distant organs and tissues was 27% lower in the RT and ADT group compared to RT alone. The group who received ADT and RT had a 7% higher chance of surviving after 120 months compared to patients receiving RT alone.

The authors concluded that 6 months of ADT plus radiotherapy reduced the risk of cancer progression in patients with increasing PSA levels after RP.

This study received funding from AstraZeneca, the manufacturer of goserelin.