Bone mineral density in prostate cancer: a comparative study of patients with prostate cancer and healthy controls using propensity score matching

Bone mineral density in Nigerian men on androgen deprivation therapy for advanced prostate cancer

Background

Cancer of the prostate (CaP) is the most frequently diagnosed non-cutaneous malignancy worldwide, and it is the second leading cause of death from cancer in men. In the developing world, majority of patients with CaP present in advanced stage and often times, androgen deprivation therapy (ADT) is the only treatment option available. ADT has been reported to increase the risk of osteopenia and osteoporosis in patients with CaP in studies done predominantly among the Caucasians. There is a dearth of report of the effect of ADT on CaP in the black population most especially Nigerian population despite our high incidence of CaP. The aim of this study was to determine the effect of advanced CaP and its treatment using ADT on bone mineral density (BMD) in our patients.

Results

The age of the patients ranged from 54 to 88 years (mean 70.15 ± 6.7) and 50 to 85 years (mean 68.92 ± 8.5) for the case and control groups, respectively. The mean BMD of the control group (0.26 ± 1.5) was significantly higher than the case group pre-ADT (− 0.78 ± 1.7) (p = 0.044). Post-ADT, the BMD was significantly lower (− 1.15 ± 1.7) than pre-ADT (p = 0.001) among the case group.

Conclusion

Advanced CaP was found to be associated with a decrease in BMD, and ADT was associated with a further decline in the BMD. Therefore, prevention and treatment of skeletal-related events is vital in management of patients with advanced CaP.

Comparison of bone mineral loss by combined androgen block agonist versus GnRH in patients with prostate cancer: A 12 month-prospective observational study

The multi-centre, prospective, observational study was designed to examine the efficacy of continuous combined androgen block (CAB) vs. GnRH agonist monotherapy in terms of bone mineral density (BMD) change during 12 months post-androgen deprivation therapy (ADT) in Asian prostate cancer patients. Multiple regression analysis and estimated the 10-year probability of major fractures among the patients with Fracture Risk Assessment Tool were conducted to investigate the underlying factors affecting BMD. Paired t-test to evaluate the change of BMD from baseline to 12 month, and two sample t-test to examine the difference of BMD changes were used between two groups. BMD significantly decreased in both the CAB and GnRH groups, with no group wise differences. The proportion of osteopenia or osteoporosis was slightly increased after the 12-month post-ADT. Ten-year probability of hip fracture and major osteoporotic fracture was approximately 3% and 5%, respectively. In conclusion, a significant decrease of BMD by 12-month ADT was observed without any differences between the two groups, whereas ADT-related BMD loss did not induce detrimental effects on bone health in terms of increased bone fracture risk. This was the first prospective study on BMD changes as a predictor of fracture during ADT in an Asian population.

Adaptive Bone Remodeling of the Femoral Bone After Tumor Resection Arthroplasty With an Uncemented Proximally Hydroxyapatite-Coated Stem

Loss of bone stock and stress shielding is a significant challenge in limb salvage surgery. This study investigates the adaptive bone remodeling of the femoral bone after implantation of a tumor prosthesis with an uncemented press fit stem. We performed a prospective 1 yr follow-up of 6 patients (mean age: 55 (26-78) yr, female/male=3/3) who underwent bone tumor resection surgery of the proximal femur (n=3) or distal femur (n=3). Reconstruction was done using a Global Modular Replacement System (Stryker® Orthopaedics, Mahwah, NJ) tumor prosthesis, and all patients received a straight-fluted 125-mm uncemented press-fit titanium alloy stem with hydroxyapatite coating of the proximal part of the stem. Measurements of bone mineral density (BMD; g/cm2) were done postoperatively and after 3, 6, and 12 mo in the part of the femur bone containing the Global Modular Replacement System stem using dual-energy X-ray absorptiometry. BMD was measured in 3 regions of interest (ROIs) in the femur bone. Nonparametric analysis of variance (Friedman test) for evaluation of changes in BMD over time. BMD decreased in all 3 ROIs with time. In ROI 1 (p=0.01), BMD decreased by 10% after 3 mo and ended with a total decrease of 14% after 1 yr. In ROI 2 (p=0.006), BMD was decreased by 6% after 3 and 6 mo; after 1 yr of follow-up, BMD was 9% below the postoperative value. In ROI 3 (p=0.009), BMD decreased by 6% after 3 and 6 mo; after 1 yr of follow-up, BMD was 8% below the postoperative value. A bone loss of 8%-9% during the first postoperative year was seen along the femoral stem, but in the bone containing the hydroxyapatite-coated part of the stem, the decrease in BMD was 14%, thus indicating that stress shielding of this part of the bone may play a role for the adaptive bone remodeling.