Shorter-duration androgen blockade found efficacious

Patients with high-risk prostate cancer who received 18 months of hormone therapy lived as long as patients treated for 36 months, Canadian researchers report.

The finding suggests that the currently recommended duration of androgen blockade therapy of 24 to 36 months can be safely shortened without affecting survival.

"Shorter term hormone therapy could have a big impact on the lives of men with prostate cancer, reducing the quantity and intensity of its unpleasant side effects as well as treatment costs," said lead author Abdenour Nabid, MD, of Centre Hospitalier Universitaire de Sherbrooke in Sherbrooke, Quebec. "For the benefit of the patients, we hope these results will convince doctors that they can stop hormone therapy after 1 and a half years instead of 2 to 3 years."

In the study, which was presented at the Genitourinary Cancers Symposium in Orlando, FL, 630 patients with high-risk, node-negative (localized) prostate cancer were randomly assigned to receive either 36 or 18 months of androgen blockade therapy (bicalutamide [Casodex] and goserelin [Zoladex]) before, during, and after pelvic and prostate radiotherapy. At a median follow-up of 77 months, comparable numbers of patients were still alive in the two treatment groups-77.1% in the 36-month group and 76.2% in the 18-month group. Five- and 10-year overall survival rates were also comparable in the 36-month and 18-month groups: 92.1% versus 86.8% and 63.6% versus 63.2% for the two groups, respectively.

Assessment of cancer-specific survival showed that halving the duration of androgen blockade therapy didn’t affect the odds of dying of prostate cancer (10-year disease-specific survival was 87.2% in both groups).

AstraZeneca provided funding for the study.