Osteoporosis during continuous androgen deprivation: influence of the modality and length of treatment.
To analyze the prevalence of osteoporosis in patients with prostate cancer with and without androgen ablation. To know the influence of the modality and the length of androgen ablation on the prevalence of osteoporosis. To analyze the relative risk of hip fracture. In a cross-sectional study, we assessed bone densitometry at the Ward's triangle of the femoral neck in 110 patients with non-metastatic prostate cancer and without biochemical relapse. A cohort of 53 patients under continuous androgen suppression during a median period of 41 months (12-191) formed the study group and 57 age-matched patients that had been submitted to a radical prostatectomy formed a control group. Both subsets of patients had similar mean age (70.4 vs. 69.2, p=0.07). Mean bone mass was 0.70 g/cm2 in patients under androgen suppression and 0.76 g/cm2 in the control group, p=0.06. The rate of osteoporosis was 41.5% (22/53) and 28.1% (16/57) respectively, p=0.16 and the odds ratio was 1.82 (95% CI 0,82-4.03). The rate of osteoporosis was 41.4% (12/29) in patients under maximal androgen blockade and 41.7% (10/24) in patients under chemical castration, p=0.735. According to the length of the androgen suppression the rate of osteoporosis was 36.4% when it was between 12 and 36 months, 42.1% from 36 to 60 months and 50% when it was longer than 60 months. While the overall relative risk of hip fracture in the control group was 2.0, it was 2.4 when the length of androgen suppression was between 12 and 36 months, 2.9 between 36 and 60 months and 3.9 when it was longer than 60 months. Androgen suppression increases the prevalence of osteoporosis in patients with prostate cancer. The modality of continues androgen suppression seems not to affect its prevalence. However the length of androgen suppression would be related to its development. The relative risk of hip fracture is also increasing during the androgen suppression.