BMD loss similar between CAB and GnRH agonist monotherapy
Asian prostate cancer patients may show a significant reduction in bone mineral density (BMD) 12 months after androgen deprivation therapy (ADT) with no difference between those on continuous combined androgen block (CAB) and those on gonadotropin-releasing hormone (GnRH) agonist monotherapy, a new study shows.
A total of 312 patients with prostate cancer were included in the study. Participants were at least 50 years of age and were scheduled to receive ADT either with CAB (n=70) or with GnRH agonist monotherapy (n=242).
Dual energy x-ray absorptiometry was used to measure BMD, while the Fracture Risk Assessment Tool (FRAX) was used to measure the 10-year probability of getting major fractures.
After 12 months of ADT treatment, the proportion of individuals with osteopenia or osteoporosis slightly increased, but the change did not significantly differ between the two groups (p=0.3688). Moreover, the mean BMD of the L-spine decreased by -0.04 in the CAB group (p<0.0009) and by -0.05 in the GnRH group (p<0.001).
The FRAX scores also showed that after 12 months, the mean 10-year probability of major fractures was 4.96 percent for the CAB group and 5.85 percent for the GnRH group. These were not significantly different from the baseline values and between the groups (p>0.05).
On the other hand, the 10-year mean probability of hip fractures was 2.41 percent for the GnRH group and 1.69 percent for the CAB group. The probability for the CAB group showed a significant increase from baseline (p=0.0231), but the difference between the groups was not significant (p=0.5531).
Finally, analysis showed that the treatment group was not associated with the changes in BMD (p>0.05).
The finding that neither CAB nor GnRH agonist monotherapy bear any clinical significance on the risk of fractures thus imply that the ADT-induced bone loss does not lead to bone-related diseases.