Prevention of Osteoporosis in Men With Prostate Cancer
Condition: Prostate Cancer; Osteoporosis; Hypogonadism
MeSH terms: Prostatic Neoplasms; Osteoporosis; Hypogonadism
Study type: Interventional
Phase: Phase 3

Summary: 
      The purpose of this two year study is to examine the safety and effectiveness of alendronate
      (Fosamax) for the prevention of bone loss in men with prostate cancer who are on therapy to
      lower their testosterone levels. All men will receive appropriate calcium and vitamin D
      supplements and one to two years of alendronate therapy. Bone density tests will be done
      every six months.
    

Detailed description: 
      Prostate cancer is the most common visceral malignancy and second leading cause of cancer
      death in men. While androgen ablation therapy is the cornerstone of treatment for more
      advanced stage disease, recent studies suggest the advantage of introducing androgen
      deprivation much earlier. Because androgens are essential in maintaining skeletal integrity
      in men, androgen deprivation therapy constitutes a major risk factor for male osteoporosis.
      We have previously demonstrated that men on chronic androgen deprivation therapy have up to
      20% loss of bone. Our hypotheses are that: 1) chronically increased bone resorption induced
      by long term androgen deprivation therapy in men with prostate cancer can be reversed with
      once weekly bisphosphonate; 2) the improvement in bone mass with bisphosphonate therapy will
      be reflected by changes in biochemical markers of bone turnover and will allow us to predict
      who will respond to therapy; and 3) following termination of bisphosphonate therapy, bone
      mass will be maintained despite the absence of antiresorptive therapy. To address these
      hypotheses, we will enroll 84 men with stage D0 prostate cancer who have been on chronic
      androgen deprivation therapy in a two year, double blind, placebo controlled, randomized,
      modified crossover clinical design. During the first year, subjects will be randomized to
      bisphosphonate therapy or placebo. During the second year, all subjects who were on placebo
      will receive active treatment and all subjects who were on active treatment will be randomly
      assigned to continue therapy or change to placebo. To evaluate the effect of bisphosphonate
      on preventing bone loss, we will assess bone mass of the spine, total hip, total body, and
      forearm by dual-energy X-ray absorptiometry. For hypothesis 2, we will assess markers of bone
      resorption and formation to determine if early changes in markers are associated with long
      term changes in bone mass. For hypothesis 3, we will continue to follow bone mass and
      biochemical markers of bone turnover between months 12 and 24 to examine rates of change when
      antiresorptive therapy is terminated. Few data are available on the prevention of bone loss
      in men on androgen deprivation therapy. This study will examine a preventive strategy, the
      potential mechanism of bone loss, the ability of biochemical markers to predict bone mass,
      and skeletal outcomes when antiresorptive therapy is withdrawn.
    

Intervention name(s): alendronate
Intervention type(s): Drug
Intervention MeSH terms: Alendronate
Allocation: Randomized
Intervention model: Crossover Assignment
Masking: Double
Primary purpose: Prevention
Keywords: Male; Osteoporosis; Prostate cancer; Hypogonadism; Bisphosphonates; Bone mineral density