THURSDAY, Aug. 13 (HealthDay News) -- Sodium clodronate improves overall survival in men with metastatic prostate cancer, but it does not reduce the risk of death in men with non-metastatic prostate cancer, according to a study published online Aug. 11 in The Lancet Oncology.
David P. Dearnaley, of the Institute of Cancer Research in Sutton, U.K., and colleagues assessed long-term overall survival from two previous studies. In one, 311 men with metastatic prostate cancer, recruited between 1994 and 1998, were starting or responding to long-term hormone therapy. In the other, 508 men with non-metastatic prostate cancer were treated mostly with radiotherapy, hormone therapy, or both. All were assigned to clodronate or placebo. For the long-term follow-up, data was available for 278 men with metastatic disease and 471 with non-metastatic disease.
The researchers determined that clodronate improved overall survival in men with metastatic disease. The estimated five-year survival for this group was 21 percent with placebo and 30 percent with clodronate; 10-year survival was 9 percent with placebo and 17 percent with clodronate. However, clodronate did not improve overall survival in those with non-metastatic disease. For this group, five-year survival was 80 percent with placebo and 78 percent with clodronate; 10-year survival was 51 percent with placebo and 48 percent with clodronate.
"PR05 is the first trial, to our knowledge, 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 for prostate cancer," the authors conclude.
The U.K. Medical Research Council and Roche Products supported the study; three authors are employed by the council.