Combining radiotherapy with hormone treatment halves prostate cancer mortality

In patients with locally advanced or high-risk prostate cancer, combining prostate radiotherapy with the conventional endocrine (hormone) treatment halves mortality. Thus endocrine treatment plus radiotherapy should be the new standard. These are the conclusions of authors on an Article published Online first and in an upcoming edition of The Lancet, written by Professor Anders Widmark, Department of Radiation Sciences, Oncology, Umeå University, Sweden, and colleagues.

In this phase III randomised trial, patients with local advanced prostate cancer were assigned to endocrine treatment alone (439 men) — consisting of three months of androgen blockage followed by continuous endocrine treatment using flutamide — or to the same endocrine treatment combined with radiotherapy (436 men).

The researchers found that after a median follow-up of 7.6 years, 79 men in the endocrine only group and 37 men in the endocrine plus radiotherapy group had died of prostate cancer. The 10-year prostate-cancer-specific mortality in the endocrine only group (23.9%) was double that of the endocrine plus radiotherapy group (11.9%). Death from any cause was also higher in the endocrine only group (39.4%) than in the endocrine plus radiotherapy group (29.6%). Cumulative incidence of recurrence of prostate cancer at 10 years, as determined by a positive test for prostate-specific antigen, was nearly three times higher in the endocrine only group (75%) than in the endocrine plus radiotherapy group (26%). After five years, urinary, rectal, and sexual problems were slightly more frequent in the combined treatment group than in endocrine only group.

The authors conclude: "The present study indicates a significant superiority of the endocrine plus radiotherapy treatment compared with endocrine treatment alone in patients with locally advanced prostate cancer. The endocrine plus radiotherapy resulted in a substantial reduction of prostate cancer mortality. This significant difference, which at 10 years reached 12%, also translated into improved difference in overall survival (9•8%).

"The quality of life and adverse effect profile [of radiotherapy] is acceptable. We therefore suggest that endocrine treatment plus radiotherapy should be the new standard of care for these patients."

In an accompanying Comment, Dr Chris Parker and Dr Alex Tan, Institute of Cancer Research, Sutton, Surrey, UK, describe the trial as pivotal and as "the first to show an overall survival advantage for radiotherapy in the primary treatment of prostate cancer."

They conclude: "The results should change current practice, making long-term hormonal therapy plus radical radiotherapy the standard of care for men with locally advanced prostate cancer."