Prediction of vertebral fractures in cancer patients undergoing hormone deprivation therapies: Reliability of WHO fracture risk assessment tool (FRAX) and bone mineral density in real-life clinical practice.

• In females under estrogen-deprivation therapies, risk of vertebral fractures was associated with FRAX score for major fractures, with the best therapeutic threshold of 6.5%. • In males under androgen-deprivation therapy, risk of vertebral fractures was high when BMD T-score was lower than −1.0 SD or when subjects were treated with abiraterone. • High body mass index was an independent risk factor for vertebral fractures in males exposed to androgen-deprivation therapy. • In the setting of hormonal deprivation therapies, FRAX and BMD thresholds were lower than those used in post-menopausal osteoporosis and primary male osteoporosis. Prediction of fractures in cancer survivors exposed to hormone-deprivation therapies (HDTs) is a challenge since bone loss is rapid and severe, and determinants of fractures in this setting are still largely unknown. In this study we investigated reliability of the WHO Fracture Risk Assessment Tool (FRAX) and bone mineral density (BMD) to identify subjects developing vertebral fractures during HDTs. Five-hundred-twenty-seven consecutive subjects (429 females with breast cancer, 98 males with prostate cancer; median age 61 years), under HDTs for at least 6 months, were evaluated for vertebral fractures by a radiological and morphometric approach, in relationship with FRAX score, body mass index (BMI), BMD, age and duration of HDTs. Vertebral fractures were found in 140 subjects (26.6%) and spine deformity index was significantly associated with duration of HDTs (rho 0.38; p < 0.001). Only in females, vertebral fractures were significantly associated with FRAX score for major fractures [OR 1.08; P < 0.001]. The best cut-off of FRAX score for major fractures, as calculated by receiving operating characteristic (ROC) analysis was 6.35%. In males, however, vertebral fractures were significantly and independently associated with BMI ≥ 25 Kg/m² (OR 17.63; P < 0.001), BMD T-score below −1.0 SD at any skeletal site (OR 7.79; P < 0.001) and gonadotropin-releasing hormone agonists (GnRHa) plus abiraterone treatment (OR 11.51; P = 0.001). FRAX and BMD may be useful for predicting vertebral fractures in subjects undergoing HDTs, but the thresholds seem to be lower than those used in the general population. High BMI is a determinant of vertebral fractures in males under HDT. [ABSTRACT FROM AUTHOR]