Background Androgen deprivation therapy (ADT) is the mainstay of treatment for non-metastatic prostate cancer1. It is known to have adverse effects including fatigue, anaemia, a decrease in lean body mass as well as a decrease in bone mineral density (BMD)1. Regulatory bodies such as NICE recognize that men on ADT should be considered for fracture risk assessment including the use of a DEXA scan2. Few conclusions have been drawn as to where this bone loss occurs and what other predictors affect bone loss.
Objectives This study aims to determine the predictors of bone loss at the femoral neck and on the lumbar spine in men being treated with androgen deprivation therapy for prostate cancer.
Methods Data was collated from patients referred for a DEXA scan at a hospital in the North West of England (UK) between 2004 and 2011. The BMD of the femoral neck (FN) and lumbar spine (L1L4) were recorded in men who had a history of ADT use, in addition to a number of predictors of osteoporosis. These predictors were examined using linear regression models to determine how they affected bone loss at the femoral neck and lumbar spine, unadjusted for age and adjusted for age.
Results 124 patients included in the study. The mean age was 75.6 years (SD 7.99). Predictors of bone loss studied included steroid therapy, tobacco use, alcohol excess, history of rheumatoid arthritis, family history of fracture, % body fat and body mass index (BMI). 15 patients had sustained a fracture. Using linear regression analysis, the only predictor found to have a significant effect on bone loss in these men was BMI, which persisted when adjusted for age (see Table 1). The T scores were lower in the FN (mean -1.22) than the L1L4 (mean -0.32). low FN BMD was the only variable that was associated with the fractures (p=0.04).
Conclusions This study identifies that the BMI of a patient on ADT is a further predictor of bone loss. This persists after adjusting for age. This effect is seen more in L1L4. This study highlights there is a need to assess patients with a low BMI and on ADT for osteoporosis and ensure appropriate preventative treatment is provided. Reducing the risk of osteoporosis will not only benefit patients in preventing future fractures but also reduce the cost to the NHS. More work into this topic is warranted.
J Clin Oncol, 25: 1038–1042.
NICE guidance CG146, http://guidance.nice.org.uk/CG146.
The Journal of Clinical Endocrinology & Metabolism 90: 12.
Disclosure of Interest None declared