Long-term androgen deprivation therapy (LT-ADT) has been associated with decreased bone mineral density (BMD) in men with prostate cancer (PCa). Some evidence suggests that there is no impact on fracture risk despite this BMD loss. Our study aimed to quantify changes in BMD in men with high risk PCa on LT-ADT and calcium and vitamin D supplementation (CalVitD).

BMD analysis was conducted for localized high-risk prostate cancer patients enrolled in the phase III randomized trial PCS-V, comparing conventional and hypofractionated Radiation therapy (RT). Patients received 28 months of luteinizing hormone-releasing hormone agonist and CalVitD (500 mg of Calcium BID+400 IU of Vitamin D3 BID). The areal density and T-scores (spine, femoral neck and total femur) at baseline and 30 months of follow-up were extracted, and the absolute change was calculated. Clinical bone density status (normal, osteopenia, osteoporosis) was monitored.

The lumbar spine, femoral neck and total femoral BMD were measured for 226, 231, and 173 patients, respectively. The mean percent change in BMD was -2.65%, -2.76% and -4.27%, for these respective sites (p <0.001 for all). The average decrease in BMD across all sites was -3.2%, with no decline in BMD category in most patients (83%). Eight-patients (4%) became osteoporotic.

Despite a mild decline in BMD, the change in clinical BMD category remained low with LT-ADT. Consequently, CalVitD alone may suffice for most localized PCa patients on LT-ADT.