- High prevalence of vitamin D deficiency1,2
- Decreased physical activity3,4
- Increased risk of falls secondary to treatment-induced neuropathy5
- Chemotherapy-induced ovarian failure6
- AI therapy7,8
International consensus guidelines6,9 recommend that anti-resorptive therapy should be initiated in AI-treated women not fulfilling the above criteria if the lowest BMD T-score is ≤–2.0 or if more than two fracture risk factors are present, and be considered where there is a >5–10% decrease in BMD in one year of AI treatment, or 10-year absolute risk of a major osteoporotic fracture of >20%, or of a hip fracture of >3%. However, this is outside current PBS of Australia subsidy criteria.
Premenopausal women commonly have normal baseline BMD with low short-term fracture risk, yet lose bone more rapidly than older postmenopausal women. Decisions regarding anti-resorptive treatment should be carefully individualised and discussed with the patient. Bisphosphonates can persist in the bone matrix for years after therapy is discontinued, potentially resulting in foetal exposure during pregnancy. Specialist referral may be appropriate.
Bone loss in most untreated women is most marked in the 12–24 months post AI initiation, and limited data suggest partial BMD recovery after cessation of AI treatment. DXA should be repeated 12 months after commencement of AI therapy, with subsequent individualised monitoring frequency.
General measures to prevent bone loss include:
- Regular moderate physical activity (weight-bearing exercises and resistance training)
- Smoking cessation
- Limitation of alcohol to <2 standard drinks per day
- Calcium intake of 1300 mg, preferably dietary
- Vitamin D supplementation to achieve and maintain 25-OH D levels >50 nmol/L
Key recommendations for the management of bone health in men receiving androgen deprivation therapy (ADT) are adapted from previously published management guidelines of the Endocrine Society of Australia, the Australian and New Zealand Bone and Mineral Society, and the Urological Society of Australia and New Zealand.10
Risk factors for osteoporosis should be ascertained, basic laboratory testing conducted (electrolytes, calcium, alkaline phosphatase and vitamin D), and hip and spine BMD measurement determined by DXA. Absolute baseline fracture risk may be estimated using mathematical tools such as the Garvan Fracture Risk Calculator or FRAX. However, neither of these algorithms is validated for men with prostate cancer receiving ADT, and they may underestimate true fracture risk. In men with a T-score ≤–1.0, thoracolumbar spine X-rays should be performed to exclude clinically silent vertebral fractures.10 DXA should be repeated 12 months after commencement of ADT, with subsequent individualised monitoring frequency.
There is currently insufficient evidence to make evidence-based recommendations regarding if and when bisphosphonate therapy for primary prevention should be commenced in men with prostate cancer who are receiving ADT. Consistent with the general recommendations in this guideline, all men older than 70 years of age with a T-score of ≤–2.5 should commence anti-resorptive therapy, and therapy should be considered if there is an annual BMD loss of 5–10% or a 10-year absolute risk of a major osteoporotic fracture of >20%, or of a hip fracture of >3%.
Australian guidelines recommend that bisphosphonate therapy should be considered for primary prevention if the BMD T-score is ≤–2.0.11 However, this recommendation is outside current PBS subsidy criteria. While bisphosphonates are recommended (and subsided by the PBS) for primary fracture prevention in glucocorticoidinduced osteoporosis when the T-score is ≤–1.5, current evidence is insufficient to recommend the same or similar T-score cut-off for men receiving ADT.
Management should also be re-evaluated after cessation of ADT, as the gonadal axis may recover in some men, with more rapid recovery reported in younger men (<65 years) or shorter (<24–30 months) duration of ADT.11
General measures to prevent bone loss should:
- Regular moderate physical activity (weight-bearing exercises and resistance training)
- Smoking cessation
- Limitation of alcohol to <2 standard drinks per day
- Calcium intake of 1000–1300 mg, preferably dietary
- 25-OH D supplementation to achieve and maintain levels >50 nmol/L