Long-term hormone therapy for men with locally advanced prostate cancer controls the disease better than short-term hormone therapy, researchers reported at the 2000 annual meeting of the American Society of Clinical Oncology. (Note: the final data were subsequently published in the Nov. 1, 2003, issue of the Journal of Clinical Oncology; see the journal abstract.)

Each year, 50,000 men in the United States fall in the category of patients followed in the trial. They have extensive cancer of the prostate, but the disease has not yet spread to other organs. These men typically get treated with radiation therapy or surgery, treatments which are "relatively ineffective in curing these patients," according to Gerald Hanks, M.D., of the Fox Chase Cancer Center in Philadelphia, who ran the study of 1,500 men. The study was known as Radiation Therapy Oncology Group protocol 92-02.

Hormone therapy shuts down testosterone, which is often responsible for making prostate cancer grow. It is commonly given for two months before and two months during radiation therapy. Side effects include hot flashes, breast growth, and decreased sex drive.

In the Fox Chase study, half of the men received an additional two years of the drug Zoladex. Fewer of these men, 33, compared with 54 in the short-term hormone treatment group, died during the study. Disease-free survival in the long-term treatment arm was 54 percent, compared with 34 percent in the short-term group. However, overall five-year survival was virtually identical in the two groups.

The largest benefit was seen in patients with a poor prognosis, those whose tumor had a Gleason score of between eight and 10. These patients had a five-year survival rate jump from 69 percent to 80 percent.

"These results set a new standard of treatment for patients with advanced localized prostate cancer," said Hanks. The study was one of the largest of prostate cancer ever undertaken.