Treatment thresholds for osteoporosis in men on androgen deprivation therapy: T-score versus FRAX

• Published in: Osteoporosis international 2010-04, Vol.21 (4), p.647-653
• Main Authors: Adler, R. A, Hastings, F. W, Petkov, V. I
• Format: Article
• Language: English
• Subjects: Adenocarcinoma - therapy; Aged; Aged, 80 and over; Algorithms; Androgen Antagonists - adverse effects; Antineoplastic Agents, Hormonal - adverse effects; Biological and medical sciences; Bone Density - drug effects; Bone Density Conservation Agents - therapeutic use; Diseases of the osteoarticular system; Endocrinology; Femur Neck - physiopathology; Fractures; Health risk assessment; Humans; Injuries of the limb. Injuries of the spine; Male; Medical sciences; Medical treatment; Medicine; Medicine & Public Health; Men; Nephrology. Urinary tract diseases; Orchiectomy - adverse effects; Origina Article; Orthopedics; Osteoporosis; Osteoporosis - drug therapy; Osteoporosis - etiology; Osteoporosis - physiopathology; Osteoporosis. Osteomalacia. Paget disease; Osteoporotic Fractures - etiology; Osteoporotic Fractures - prevention & control; Patient Selection; Prostate cancer; Prostatic Neoplasms - therapy; Rheumatology; Risk Assessment - methods; Traumas. Diseases due to physical agents; Tumors of the urinary system; Urinary tract. Prostate gland
• ISSN: 0937-941X; 1433-2965
• DOI: 10.1007/s00198-009-0984-0

Summary Men treated by androgen deprivation therapy (ADT) for localized prostate cancer are at risk for fracture, but it is not known which men require pharmacologic treatment. We found that 33% of men on ADT had osteoporosis of spine, hip, or forearm by dual-energy X-ray absorptiometry (DXA), thus requiring treatment. Using the new fracture prediction algorithm (FRAX™) tool with corrected femoral neck T-score identified only 17% requiring treatment, and, if calculated without femoral neck, 54% were identified to need treatment. Introduction Men treated with androgen deprivation therapy (ADT) for prostate carcinoma live long enough to fracture. A new fracture prediction method, FRAX™, is based on femoral neck DXA plus risk factors. Thus, DXA or FRAX™ could determine which men should receive osteoporosis therapy. Methods Of 115 men undergoing ADT referred for DXA testing, those with bone mineral density (BMD) in spine, hip, or forearm of ≥2.5 standard deviations below a normal male ethnicity-adjusted mean were considered treatment candidates. Using FRAX™ with and without femoral neck BMD, men were treatment candidates if the 10-year hip fracture risk was ≥3% or the major osteoporotic fracture risk was ≥20%. Results The men averaged 77 years old; 58% were African-American, and 14.8% were current smokers. Mean femoral neck T-score was −1.4. Using DXA, 38 (33%) men would need treatment. When FRAX™ was calculated including the femoral neck T-score, only 20 men met criteria for treatment. However, when FRAX™ was calculated without the T-score, 62 men met criteria for treatment. Overlap among the groups was surprisingly modest. Conclusions DXA and FRAX™ identify different ADT men for treatment.