Journal of Osteoporosis 95% CI 0.15–0.70 0.42–1.00 0.22–0.78 0.82–1.00 0.18–1.00 0.39–1.00 0.30–1.00 0.84–1.00 0.42 0.72 0.50 0.94 0.64 0.74 0.69 0.95 Table 4: FRAX score in the prediction of vertebral fracture in men with prostate cancer. All Subjects (N = 78; vertebral Fx = 22/78 = 24.4%) Non-African-American (N = 59; vertebral Fx = 18/59 = 31%) ROC AUC African-American (N = 19; vertebral Fx = 4/19 = 21%) ROC AUC before X-ray after X-ray before X-ray after X-ray before X-ray after X-ray before X-ray after X-ray ROC AUC 0.55 0.66 0.59 0.74 0.53 0.66 0.54 0.72 95% CI 0.39–0.70 0.53–0.78 0.43–0.75 0.62–0.85 0.37–0.69 0.52–0.80 0.38–0.69 0.60–0.84 0.59 0.63 0.66 0.73 0.60 0.63 0.62 0.70 95% CI 0.42–0.77 0.47–0.78 0.48–0.84 0.59–0.87 0.42–0.79 0.47–0.79 0.43–0.82 0.55–0.84 4 FRAX (Hip) without BMD FRAX (Osteo) without BMD FRAX (Hip) with BMD FRAX (Osteo) with BMD ROC: receiver operating characteristic; AUC: area under the curve; CI: conﬁdence interval. BMD: Bone mineral density; Osteo: osteoporotic. Discovery of incidental vertebral fractures on spine ﬁlms increased the predictive ability for vertebral fracture of all types of FRAX scores: hip FRAX with or without BMD and osteoporotic FRAX with or without BMD (Table 4). All post- X-ray hip FRAX and osteoporotic FRAX were statistically signiﬁcant (AUC signiﬁcantly diﬀerent from of 0.50). Osteoporotic FRAX demonstrated greater predictive ability for vertebral fracture than hip FRAX, 0.74 versus 0.66 AUC, respectively, without BMD (P = 0.01) and 0.72 versus 0.66 AUC, respectively, with BMD (P = 0.04). The ROC models for predictive ability of FRAX were not signiﬁcantly changed by including a factor accounting for whether the patient was already on ADT. Thus, data for all 78 patients (63 already on ADT, 15 not on ADT) is displayed. The inclusion of BMD in FRAX calculations did not aﬀect the predictive ability of FRAX. FRAX scores calculated with and without BMD were signiﬁcantly related (Table 2). Spearman correlation coeﬃcients were rho = 0.80 (P < 0.001) for osteoporotic FRAX (Figure 1(a)) and rho = 0.71 for hip FRAX (P < 0.001) (Figure 1(b)). There were too few fractures in the African-American group to give adequate precision so conclusions cannot be reliably drawn from the African-American-speciﬁc data. ROC AUC appears high in AAs because of high speciﬁcity due to low incidence of vertebral fracture (Table 4). Race was not correlated with spine BMD in multivariate linear regression models controlling for age, PSA level, and use of vitamin D supplementation. The PSA level showed a positive correlation with lumbar spine BMD (Figure 2) in both the univariate linear regression model (P = 0.03) and the multivariate linear regression models controlling for age, weight, and use of vitamin D supplements (P = 0.04), as displayed in Table 3, and accounted for about 9% of spine BMD. Weight correlated with BMD in the spine (rho = 0.25, P = 0.03), femoral neck (rho = 0.43, P < 0.0001), and total hip (rho = 0.43, P = 0.0001) (data not shown). Age had a positive correlation with BMD at lumbar spine (P < 0.02) but not at femoral neck or total hip. From other secondary outcomes, neither duration of ADT, level of 25-hydroxyvitamin D, parathyroid hormone, total alkaline phosphatase, nor total testosterone levels pre- dicted BMD or fractures at any site in our study population. 25-hydroxyvitamin D level was found to be below 20 ng/mL in 31% and 20–30 ng/mL in 20% of men. In the other 49% of men, 25-hydroxyvitamin D was above 30 ng/mL. 4. Conclusions The utility of height loss and FRAX scores as predictors of fractures in men with prostate cancer had not been previously studied. In our study population of older men with prostate cancer, most of whom were on ADT, height loss was similar in men with and without compression fractures and other osteoporosis-related fractures. In conclusion, our study cannot suggest a threshold of height loss for which spine X-rays or perhaps vertebral fracture assessment with DXA should be used. As with prior studies by Adler et al. [11] and Saylor et al. [10], fewer men met treatment criteria when BMD was included in FRAX score calculation. Also, fewer men met treatment threshold for major osteoporotic fracture risk than for hip fracture risk. Compared to Adler et al., our study population had similar age (both with median age 77 years) and weight (85.5 kg versus 88.1 kg in Adler et al.) and excluded men with fractures secondary to bone metastases (versus 30% with bone metastases in Saylor et al.). Our study population was 24% African-American population, compared to 58% in Adler et al. and 5% in Saylor et al. The utility of FRAX in predicting fracture incidence in men with prostate cancer had not been studied previously. An advantage of the current study is that incidence of vertebral fracture was known due to spine radiographs,