Several factors increase fracture risk with androgen deprivation for prostate cancer
Wednesday, 31 August 2010 - A Canadian study has identified several readily available clinical factors that help determine the risk of fractures in men with prostate cancer undergoing androgen deprivation therapy (ADT).
Independent predictors of bone fragility and any fracture were increasing age, prior bone thinning medications, chronic kidney disease, dementia, prior fragility fracture, and osteoporosis diagnosis or treatment, the investigators report in the September Journal of Urology
"This information should supplement a bone mineral density test, which should be done at baseline in all men starting any form of ADT (intermittent or continuous)," lead author Dr. Shabbir M. H. Alibhai, from the University Health Network in Toronto, Ontario, told Reuters Health by e-mail.
"Androgen deprivation therapy increases the risk of both fragility and non-fragility fractures, and patients and doctors need to be aware of this," Dr. Alibhai said.
To reduce fracture risks, he advises calcium and vitamin D supplements for men starting ADT, unless they have contraindications. "Prescription therapies (a bisphosphonate, denosumab, or toremifene) should be tailored to the patient's risk for fracture, which is based on clinical risk factors (including age), and bone density results," he said.
Dr. Alibhai and colleagues used linked administrative databases to analyze just over 19,000 prostate cancer patients with at least 6 months of ADT or bilateral orchiectomy. The researchers matched these men by age, cancer treatment, comorbidity, prior fractures and socioeconomic status to the same number of men who had never been on ADT.
During a mean follow-up of 6.47 years there were 3387 fractures of any type among the ADT users and 2495 among the non-users, yielding an adjusted hazard ratio of 1.46 for fracture associated with ADT.
The numbers of fragility fractures of the spine, lower arm, hip or femur in the two groups were 1778 and 1157, respectively, for a hazard ratio of 1.65.
In an editorial comment, Dr. Philip J. Saylor of Massachusetts General Hospital Cancer Center Boston, concurs with Dr. Alibhai, writing, "We must move beyond bone mineral density as a stand-alone tool to estimate fracture risk."
Source: Reuters Health / J Urol 2010;184:918-924.
