Comparison of fracture risk assessment tool score to bone mineral density for estimating fracture risk in patients with advanced prostate cancer on androgen deprivation therapy

Abstract

Objective: To estimate the risk of fracture (Fracture Risk Assessment Tool [FRAX] algorithm) because of the development of osteoporosis in prostate cancer patients undergoing androgen deprivation therapy (ADT) for patients who would otherwise not have been identified for treatment by the T score.

Methods: This study includes men undergoing ADT for prostate cancer at our urology group. Clinical data were collected via chart review. Subjects were evaluated for fracture risk using country specific (for the United States of America) World Health Organization's FRAX. The FRAX calculations were then compared to fracture risk as determined by T score, for a subset of our cohort that received dual-energy X-ray absorptiometry.

Results: Our cohort consisted of 613 patients on ADT, 94 of which had a dual-energy X-ray absorptiometry scan. The FRAX algorithm identified 61.6% patients requiring therapy without bone mass density (BMD), 46.8% with BMD, and 19.14% with T score alone. In addition, positive correlation was found between FRAX with and without BMD as well as T score and FRAX with BMD and without BMD.

Conclusion: Our data indicate that many patients who were not found at significant risk for fracture with T score were in fact found to be at risk with the FRAX calculation. The largest proportion of patients was found to be at risk through the FRAX calculation without BMD, followed by FRAX with BMD, followed by T score alone. The utility of FRAX is beneficial in identifying patients that may benefit from effective bone-tropic treatment modalities.