toremifene and Spinal-Fractures

Osteoporosis is defined as a continuous loss of bone mineral density accompanied by an increased fracture risk in females and males. A fall of estrogen concentrations at the menopause and the consecutive rapid bone loss are an established pathogenic mechanism in female osteoporosis. Males do not have a menopause equivalent during which significant amounts of bone are lost. Several diseases, therapeutic strategies and nutritional deficiencies may also result in bone loss and reduced bone mineral density. Prostate cancer is the most common visceral malignancy in men. Suppression of endogenous androgen production as a therapeutic tool is commonly used in patients with non-metastatic prostate cancer and is associated with significant bone loss and an increased fracture risk. Androgen deprivation therapy is prescribed both for men with locally advanced or high-risk non-metastatic prostate cancer. Osteoclast inhibition with any of several bisphosphonates improves bone mineral density and reduces fracture risk. Denosumab (a monoclonal antibody against RANK ligand) and toremifene (a selective estrogen receptor modulator) recently have been shown to be effective to reduce vertebral fractures in patients with non-metastatic prostate cancer receiving androgen-deprivation therapy. This overview focuses on cancer-treatment-induced bone loss in patients with non-metastatic prostate cancer.

Topics: Aged, 80 and over; Androgen Antagonists; Antibodies, Monoclonal, Humanized; Antineoplastic Agents, Hormonal; Bone Density; Bone Density Conservation Agents; Denosumab; Diphosphonates; Gonadotropin-Releasing Hormone; Humans; Male; Neoplasm Staging; Osteoclasts; Osteoporosis; Osteoporotic Fractures; Prostatic Neoplasms; Randomized Controlled Trials as Topic; RANK Ligand; Selective Estrogen Receptor Modulators; Spinal Fractures; Toremifene

Androgen deprivation therapy for prostate cancer causes accelerated loss of bone mineral density and is associated with increased fracture risk. We evaluated risk factors associated with vertebral fractures among men enrolled in a fracture prevention trial.. Analysis included men receiving androgen deprivation therapy for prostate cancer and enrolled in a phase III fracture prevention trial. All men were 70 years old or older or had a low bone mineral density (T-score less than -1.5 for the lumbar spine or total hip). We analyzed demographic and laboratory characteristics of men with and those without vertebral fractures at study entry.. Of the 1,244 subjects 162 (13.0%) had a vertebral fracture at baseline. The 2 factors significantly associated with vertebral fractures were white race (p=0.028 compared with nonwhite race) and osteoporosis (p=0.002 for osteoporosis at any site, p=0.053 for osteoporosis at the spine, p=0.002 for osteoporosis at the hip). Lower bone mineral density was also significantly associated with vertebral fractures when analyzed as a continuous variable. Factors not associated with vertebral fractures included age, country of residence, androgen deprivation therapy duration at baseline, androgen deprivation therapy mode, body mass index, testosterone, estradiol, C-telopeptide, bone specific alkaline phosphatase and osteocalcin. Results were similar in analyses limited to men 70 years old or older.. White race and low bone mineral density were significantly associated with vertebral fractures in this study of men treated with androgen deprivation for prostate cancer. These observations should inform the assessment and management of fracture risk among such men.

Topics: Aged; Androgen Antagonists; Bone Density Conservation Agents; Double-Blind Method; Humans; Male; Prostatic Neoplasms; Risk Factors; Spinal Fractures; Toremifene

Androgen deprivation therapy is associated with an increased fracture risk. In a recent phase III trial toremifene significantly decreased vertebral fractures in men on androgen deprivation therapy. Similar to other selective estrogen receptor modulators, toremifene was associated with an increase in venous thromboembolic events with the greatest risk in men 80 years old or older. In this post hoc analysis we evaluated the efficacy and safety of toremifene in men younger than 80 years.. This analysis included 847 men younger than 80 years, of whom 430 received toremifene 80 mg by mouth daily and 417 received placebo for up to 24 months. The primary end point was new vertebral fractures. Secondary end points included fragility fractures, bone mineral density and safety.. Compared with placebo, toremifene decreased the relative risk of new vertebral fractures by 79.5% (95% CI 29.8-94.0, p <0.005). The new vertebral fracture incidence was 1.0% for toremifene and 4.8% for placebo (absolute risk reduction 3.8%). Compared with placebo, toremifene significantly decreased the incidence of nontraumatic fracture or greater than 7% bone loss by 24 months (p <0.0001). Toremifene also significantly increased bone mineral density at all measured sites (all comparisons p <0.001). The incidence of venous thromboembolic events was similar in the toremifene and placebo groups (2.1% and 1.0%, respectively, p = 0.26). The rates of other adverse events were also similar between the groups.. Toremifene significantly decreased new vertebral fractures in men younger than 80 years receiving androgen deprivation therapy for prostate cancer. The risk of venous thromboembolic events was lower than in the overall study population, suggesting an improved risk-benefit profile in younger men.

Topics: Aged; Androgen Antagonists; Bone Density Conservation Agents; Double-Blind Method; Humans; Male; Prospective Studies; Prostatic Neoplasms; Spinal Fractures; Toremifene