title: Frequency of zoledronic acid to prevent further bone loss in osteoporotic patients undergoing androgen deprivation therapy for prostate cancer.
abstract: OBJECTIVE
  To evaluate the efficacy of zoledronic acid (ZA) in osteoporotic patients with prostate cancer receiving either luteinizing hormone-releasing hormone agonists (LHRHA, which accelerate bone loss) or bicalutamide (which preserves bone mineral density, BMD) as androgen-deprivation therapy is the mainstay of treatment for advanced prostate cancer, and many patients are osteoporotic at presentation, with others becoming so on treatment.
  
  
  METHODS
  Fifty-eight osteoporotic men with non-metastatic prostate cancer were followed for 3 years. Patients were randomly assigned to receive either LHRHA (29) or bicalutamide (29). All received 4 mg ZA 3-monthly for 1 year. BMD was measured by dual energy X-ray absorptiometry at four times: 1 year before ZA; immediately before ZA; after five infusions; and 1 year afterwards. Bone turnover markers (BTMs) were measured at 3-monthly intervals on ZA and 1 year later. All patients had radiography of the thoracolumbar spine at baseline and after ZA.
  
  
  RESULTS
  Patients on LHRHA showed a 4.9% decrease in BMD before ZA, a 1.6% increase after ZA and a 3.0% decrease 1 year later, compared to 2.0% increase, 7.8% increase and 1.9% decrease, respectively, in those on bicalutamide. BTMs decreased significantly after ZA. Seven patients (12%) had vertebral fractures at baseline, with none deteriorating at 1 year; two (3.5%) developed mandibular osteonecrosis.
  
  
  CONCLUSIONS
  Before ZA, BMD decreased on LHRHA, but was maintained on bicalutamide. Treatment with 3-monthly ZA increased BMD and suppressed BTMs in osteoporotic patients both on LHRHA and bicalutamide, but to a greater extent in the latter. However, 1 year after the last infusion, BMD declined, suggesting that annual administration is inadequate in these patients. The optimum frequency might be related to BMD at time of bisphosphonate initiation.
authors.affiliation: Department of Urology, Wirral University Teaching Hospitals, Wirral, UK.
authors.forename: Vivek K
authors.initials: VK
authors.lastname: Wadhwa
authors.forename: Robin
authors.initials: R
authors.lastname: Weston
authors.forename: Nigel J
authors.initials: NJ
authors.lastname: Parr
mesh_terms: D015502:Absorptiometry, Photon; D000368:Aged; D000369:Aged, 80 and over; D000726:Androgen Antagonists / Q000009:adverse effects*; D000813:Anilides / Q000009:adverse effects; D050071:Bone Density Conservation Agents / Q000627:therapeutic use*; D004164:Diphosphonates / Q000627:therapeutic use*; D005500:Follow-Up Studies; D007987:Gonadotropin-Releasing Hormone / Q000819:agonists; D006801:Humans; D007093:Imidazoles / Q000627:therapeutic use*; D008297:Male; D008875:Middle Aged; D009570:Nitriles / Q000009:adverse effects; D010024:Osteoporosis / Q000139:chemically induced / Q000517:prevention & control*; D011446:Prospective Studies; D011471:Prostatic Neoplasms / Q000188:drug therapy*; D014105:Tosyl Compounds / Q000009:adverse effects; D000077211:Zoledronic Acid
chemical_list: D000726:Androgen Antagonists; D000813:Anilides; D050071:Bone Density Conservation Agents; D004164:Diphosphonates; D007093:Imidazoles; D009570:Nitriles; D014105:Tosyl Compounds; D007987:Gonadotropin-Releasing Hormone; D000077211:Zoledronic Acid; C053541:bicalutamide