This prospective observational study examined the effect of CAB vs. GnRH agonist monotherapy on longitudinal BMD change and calculated the 10-year probability of major fractures to determine the underlying factors affecting the ADT-related, but not tumour-related risk factors of BMD change during 12 months post-ADT initiation in prostate cancer patients. Here, GNRH1 is linked to Familial prostate cancer.