Prostate Ca: Annual Zoledronic Acid Protects Bone : Prostate cancer patients taking androgen-deprivation therapy had higher BMD after the Zometa treatment.

ATLANTA — An annual dose of zoledronic acid can prevent bone loss in men undergoing androgen-deprivation therapy for nonmetastatic prostate cancer, Dr. M. Dror Michaelson reported at the annual meeting of the American Society of Clinical Oncology.

Investigators randomized 40 men who were being treated with gonadotropin-releasing hormone (GnRH) agonists to a single 4-mg intravenous dose of zoledronic acid (Zometa) or placebo.

Twelve months later, the men treated with zoledronic acid had average bone mineral density (BMD) increases of 4% in the lumbar spine and 0.7% in the total hip. The placebo group lost 3.1% of BMD in the lumbar spine and 1.9% in the total hip.

Two bone turnover markers, serum N-telopeptide and bone alkaline phosphatase, decreased during this same period in the men given zoledronic acid and increased in the placebo group. The differences were statistically significant.

“Annual zoledronic acid should be considered in GnRH-agonist treated men who may be at risk for osteoporosis,” Dr. Michaelson, of Massachusetts General Hospital Cancer Center, said on behalf of coinvestigators from his institution and the Dana-Farber Cancer Institute, both in Boston.

Dr. Michaelson said concern about side effects drew the group to explore annual dosing as an alternative to more frequent bisphosphonate use in these patients.

GnRH agonists are known to decrease bone mineral density while increasing bone turnover and fracture risk. Studies have shown that pamidronate as well as zoledronic acid can increase BMD in prostate cancer patients receiving hormonal therapy. Frequent bisphosphonate use can cause serious side effects, however, particularly renal insufficiency and osteonecrosis of the jaw. An annual dose of zoledronic acid had been shown to prevent bone loss in postmenopausal women, but Dr. Michaelson said the strategy had not been tested in men.

The trial excluded prostate cancer patients with metastatic bone disease, prostate-specific antigen evidence of progression, or osteoporosis. The men enrolled had an average age in the mid-60s. All patients in both arms of the study were encouraged to take daily supplements of calcium and vitamin D, Dr. Michaelson said.

In a discussion of the trial, Dr. Ian F. Tannock said the biomarkers were a reasonable surrogate end point for fracture risk. Although small, the trial probably was large enough to produce significant findings, he said, noting that the results are consistent with those of other studies. “I think those conclusions are reasonable,” said Dr. Tannock, the Daniel E. Bergsagel professor of medical oncology at Princess Margaret Hospital and the University of Toronto.

Estimating the cost of 4 mg of zoledronic acid to be about $600, he asked whether less-frequent dosing also could be effective in men with metastatic prostate cancer. “I think we should consider using that very expensive medication less often in that group of men, also,” he said.

Novartis Oncology and the Prostate Cancer Foundation supported the study.

ATLANTA — An annual dose of zoledronic acid can prevent bone loss in men undergoing androgen-deprivation therapy for nonmetastatic prostate cancer, Dr. M. Dror Michaelson reported at the annual meeting of the American Society of Clinical Oncology.

Investigators randomized 40 men who were being treated with gonadotropin-releasing hormone (GnRH) agonists to a single 4-mg intravenous dose of zoledronic acid (Zometa) or placebo.

Twelve months later, the men treated with zoledronic acid had average bone mineral density (BMD) increases of 4% in the lumbar spine and 0.7% in the total hip. The placebo group lost 3.1% of BMD in the lumbar spine and 1.9% in the total hip.

Two bone turnover markers, serum N-telopeptide and bone alkaline phosphatase, decreased during this same period in the men given zoledronic acid and increased in the placebo group. The differences were statistically significant.

“Annual zoledronic acid should be considered in GnRH-agonist treated men who may be at risk for osteoporosis,” Dr. Michaelson, of Massachusetts General Hospital Cancer Center, said on behalf of coinvestigators from his institution and the Dana-Farber Cancer Institute, both in Boston.

Dr. Michaelson said concern about side effects drew the group to explore annual dosing as an alternative to more frequent bisphosphonate use in these patients.

GnRH agonists are known to decrease bone mineral density while increasing bone turnover and fracture risk. Studies have shown that pamidronate as well as zoledronic acid can increase BMD in prostate cancer patients receiving hormonal therapy. Frequent bisphosphonate use can cause serious side effects, however, particularly renal insufficiency and osteonecrosis of the jaw. An annual dose of zoledronic acid had been shown to prevent bone loss in postmenopausal women, but Dr. Michaelson said the strategy had not been tested in men.

The trial excluded prostate cancer patients with metastatic bone disease, prostate-specific antigen evidence of progression, or osteoporosis. The men enrolled had an average age in the mid-60s. All patients in both arms of the study were encouraged to take daily supplements of calcium and vitamin D, Dr. Michaelson said.

In a discussion of the trial, Dr. Ian F. Tannock said the biomarkers were a reasonable surrogate end point for fracture risk. Although small, the trial probably was large enough to produce significant findings, he said, noting that the results are consistent with those of other studies. “I think those conclusions are reasonable,” said Dr. Tannock, the Daniel E. Bergsagel professor of medical oncology at Princess Margaret Hospital and the University of Toronto.

Estimating the cost of 4 mg of zoledronic acid to be about $600, he asked whether less-frequent dosing also could be effective in men with metastatic prostate cancer. “I think we should consider using that very expensive medication less often in that group of men, also,” he said.

Novartis Oncology and the Prostate Cancer Foundation supported the study.

ATLANTA — An annual dose of zoledronic acid can prevent bone loss in men undergoing androgen-deprivation therapy for nonmetastatic prostate cancer, Dr. M. Dror Michaelson reported at the annual meeting of the American Society of Clinical Oncology.

Investigators randomized 40 men who were being treated with gonadotropin-releasing hormone (GnRH) agonists to a single 4-mg intravenous dose of zoledronic acid (Zometa) or placebo.

Twelve months later, the men treated with zoledronic acid had average bone mineral density (BMD) increases of 4% in the lumbar spine and 0.7% in the total hip. The placebo group lost 3.1% of BMD in the lumbar spine and 1.9% in the total hip.

Two bone turnover markers, serum N-telopeptide and bone alkaline phosphatase, decreased during this same period in the men given zoledronic acid and increased in the placebo group. The differences were statistically significant.

“Annual zoledronic acid should be considered in GnRH-agonist treated men who may be at risk for osteoporosis,” Dr. Michaelson, of Massachusetts General Hospital Cancer Center, said on behalf of coinvestigators from his institution and the Dana-Farber Cancer Institute, both in Boston.

Dr. Michaelson said concern about side effects drew the group to explore annual dosing as an alternative to more frequent bisphosphonate use in these patients.

GnRH agonists are known to decrease bone mineral density while increasing bone turnover and fracture risk. Studies have shown that pamidronate as well as zoledronic acid can increase BMD in prostate cancer patients receiving hormonal therapy. Frequent bisphosphonate use can cause serious side effects, however, particularly renal insufficiency and osteonecrosis of the jaw. An annual dose of zoledronic acid had been shown to prevent bone loss in postmenopausal women, but Dr. Michaelson said the strategy had not been tested in men.

The trial excluded prostate cancer patients with metastatic bone disease, prostate-specific antigen evidence of progression, or osteoporosis. The men enrolled had an average age in the mid-60s. All patients in both arms of the study were encouraged to take daily supplements of calcium and vitamin D, Dr. Michaelson said.

In a discussion of the trial, Dr. Ian F. Tannock said the biomarkers were a reasonable surrogate end point for fracture risk. Although small, the trial probably was large enough to produce significant findings, he said, noting that the results are consistent with those of other studies. “I think those conclusions are reasonable,” said Dr. Tannock, the Daniel E. Bergsagel professor of medical oncology at Princess Margaret Hospital and the University of Toronto.

Estimating the cost of 4 mg of zoledronic acid to be about $600, he asked whether less-frequent dosing also could be effective in men with metastatic prostate cancer. “I think we should consider using that very expensive medication less often in that group of men, also,” he said.

Novartis Oncology and the Prostate Cancer Foundation supported the study.