Bone mineral density in Japanese prostate cancer patients under androgen-deprivation therapy

Abstract

Androgen-deprivation therapy (ADT) of patients with prostate cancer (PCa) is known to reduce bone mineral density (BMD). However, the most studies examined Caucasian or black patients and the effects of ADT on the bone metabolism of East Asians are unclear. Therefore, we performed a crosssectional study to elucidate the influence of ADT on bone metabolism in Japanese patients. In total, 101 native Japanese patients with PCa were enrolled. They consisted of 58 ADT-treated and 43 hormone-naive patients. The BMD in the lumbar spine, total hip, and femoral neck was measured by dual energy X-ray absorptiometry and expressed in S.D. units relative to young adult men (T-score) or age-matched men (Z-score). Serum levels of bone metabolism markers were also measured. The BMDs at the three sites revealed that 2.3% (1/43) and 8.6% (5/58) of the hormone-naive and ADT-treated PCa patients had osteoporosis respectively, but this difference failed to achieve statistical significance (PZ0.294). The two groups also did not differ significantly in their Z-scores of the three sites, and univariate and multivariate analyses indicated that ADT was not a significant risk factor for decreased BMD. In addition, a significant correlation between the duration of ADT and BMD was not observed for all three sites measured. However, the ADT-treated patients had significantly higher serum levels of N-terminal telopeptide of type I collagen (NTx) than the hormone-naive patients (PZ0.017). To our knowledge, this is the first study to demonstrate the low prevalence of osteoporosis in both ADT-treated and hormone-naive Japanese PCa patients. Moreover, ADT did not significantly increase the prevalence of osteoporosis in this Japanese population. Endocrine-Related Cancer (2008) 15 943-952

Osteoporosis and prostate cancer: a cross-sectional study of Danish men with prostate cancer before androgen deprivation therapy

“…Hussain et al [22] reported that 42% were osteoporotic in a cohort of 176 patients, whereas Morote et al [13] showed an osteoporosis rate of 35.4% in a cohort of 124 patients. Finally, Wang et al [23] reported that 2.3% had osteoporosis among a cohort of 46 ADT-naïve patients. The variation in prevalence of osteoporosis regarding the two first studies is partly caused by the change in consensus of the definition of osteoporosis; both used the old WHO definition, from before 2005, in which both Ward's area and the greater trochanter were included as separate areas, which often resulted in a higher prevalence of osteoporosis.…”

“…The age of the hormone-naïve patients in Morote et al [13] was not reported. Regarding the study by Wang et al [23], the cohort was small and included a Japanese population, which may explain the low prevalence of osteoporosis [25].…”

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

“…African Americans older than 65 years have significantly higher BMD with a similar decline in BMD as compared to Caucasians2425, which may explain the reduced incidence of hip fracture in African Americans, as compared to Caucasians25; whereas, another study on Jamaican men showed ADT with lower BMD26. Some different cross-sectional Asian studies reported that Short-term ADT of an average 23.5 months did not increase the risk of osteoporosis in Japanese prostate cancer patients and ADT was not a significant risk factor for decreased BMD2728. Japanese men exposed to ADT have lower rates of osteoporosis with 2.3% and 8.6% in the hormone-naïve and ADT-treated patients, respectively, which was not statistically significant (p = 0.294).…”

Androgen deprivation therapy, diabetes and poor physical performance status increase fracture risk in Chinese men treated for prostate cancer

“…Two studies from the same Japanese research group investigated the effects of ADT on bone mineral density in ADT-treated and hormone-naïve Japanese men. The first study is a cross-sectional study which included 58 ADT-treated and 43 hormone-naïve Japanese prostate cancer patients [22]. The differences in bone mineral density values measured at the lumbar spine, total hip and femoral neck between the two groups of patients did not reach statistical significance.…”