Bone Mineral Density in Prostate Cancer: A Comparative Study of Patients With Prostate Cancer and Healthy Controls Using Propensity Score Matching

Abstract

To determine whether the prevalence of prostate cancer is associated with a decrease in bone mineral density (BMD) compared to a healthy control group and to identify the factors associated with osteoporosis in patients diagnosed with prostate cancer before the initiation of any kind of treatment. A retrospective study was conducted in 582 patients with prostate cancer and 2536 healthy men. Confounding variables affecting BMD, including age, serum testosterone, body mass index (BMI), diabetes mellitus, hypertension, and smoking were matched in the 2 study groups using propensity score analysis. The propensity score model included 6 variables, and matching by propensity score yielded 502 patients in the prostate cancer group matched to 502 men in the healthy control group. On the basis of the lowest T-score available, a high prevalence of osteoporosis was found in the prostate cancer group (P = .0001). Prostate cancer was the factor correlating significantly with osteoporosis before propensity score matching (odds ratio [OR] 2.96, P <.001) and after propensity score matching (OR 3.22, P <.001). By multivariate analysis, conducted to assess the significance of each variable affecting the development of osteoporosis in patients with prostate cancer, bone metastasis was found to be an independent predictor of osteoporosis (OR 3.45, P = .002), along with BMI (continuous, OR 0.75, P <.001). After controlling for variables affecting BMD, prostate cancer was a risk factor for osteoporosis. Measurement of BMD is a logical first step in the clinical strategy to avoid or minimize potential bone-related complications in men with prostate cancer, especially if they have bone metastasis and a slender stature.