LONDON - Treating advanced prostate cancer with radiation and hormone-blocking drugs cut the death rate in half in a study of Scandinavian men, researchers report. In the United States, the combination has been standard care since the 1990s. But in Europe, many doctors have avoided the combo treatment and used hormone drugs alone, thinking the pair would be too harsh for most patients.

"What this study shows is that men with prostate cancer do benefit from more aggressive therapy," said Dr. Howard Sandler, of Cedars-Sinai Medical Center in Los Angeles and a spokesman for the American Society of Clinical Oncology.

The Scandinavian rearchers tracked 875 men with advanced prostate cancer in Denmark, Norway and Sweden.

About half were given hormone-blocking drugs while the other half got the same treatment plus radiation. The drugs block production of testosterone, which feeds cancer cells.

After nearly eight years, 79 men in the hormone only group had died of prostate cancer, compared to 37 in the group that had hormone therapy plus radiation.

"It's not enough just to put patients on hormones," said Anders Widmark of Umea University in Sweden, one of the paper's authors. "To get a dramatic increase in survival, you have to add radiation. This should be the new standard."

The study was published online Tuesday by the British medical journal, Lancet. It was paid for by various Scandinavian cancer groups, Umea University and the makers of the drugs used in the study, Schering-Plough Corp. (Lupron), and Abbott Laboratories Inc. (Eulexin).

Adding radiation to patients' treatment did come at a cost. After five years, men receiving hormones and radiation reported higher rates of side effects including fatigue, insomnia, and sexual problems.

Prostate cancer is the most common cancer in men, and usually strikes after age 50.

While the combination treatment is recommended in U.S. guidelines, Sandler said not all patients get it. He said men who are being treated with hormones alone should talk to their doctor so see if radiation should be added.

"Combining hormones and radiotherapy should now be available to patients universally," said Chris Parker of the Institute of Cancer Research in Surrey, England.