Aug. 11 (HealthDay News) -- Oral sodium clodronate improves overall survival in advanced prostate cancer patients but doesn't reduce the risk of death in those with localized disease, British researchers say.

They reported on the long-term survival outcomes of more than 800 men enrolled in two trials launched in 1994. The trials examined the effects of sodium clodronate in patients with advanced (311 men) or localized prostate cancer (508 men).

The advanced prostate cancer patients who received the drug had a 23 percent lower death rate than patients who took a placebo. After five years, overall survival was 30 percent among men who took oral sodium clodronate and 21 percent among those in the placebo group. After 10 years, the survival rates were 17 percent and 9 percent, respectively, the researchers found.

However, the drug offered no improvement in overall survival to men with localized prostate cancer. After five years, overall survival was 78 percent among those who took clodronate and 80 percent among those given a placebo. After 10 years, the survival rates were 48 percent and 51 percent, respectively.

The findings are believed to be the first "to show an overall survival benefit conferred by an oral bisphosphonate when given in addition to standard hormone therapy to men with bone metastases who are starting or responding to hormone therapy," wrote Matthew Sydes, of the Medical Research Council Clinical Trials Unit, and colleagues. "However, there is no evidence that clodronate is of any benefit when given as an adjuvant to treatment in men with non-metastatic prostate cancer."

The study appears online and in the September print issue of The Lancet Oncology.

SOURCE: The Lancet Oncology, news release, Aug. 10, 2009