Preventing fractures in older patients on ADT

Men with prostate cancer who are 70 years of age or older, and who are starting adjuvant androgen deprivation therapy (ADT) for locally advanced or high-risk localized prostate cancer, should receive a bone mineral density (BMD) test followed by selective bisphosphonate therapy for those with osteoporosis, according to an article in today’s issue of Annals of Internal Medicine.

Ito et al. set out to analyze the value of testing BMD prior to adjuvant ADT in men with localized prostate cancer. The fundamental question they wanted to address was whether it is cost-effective to undertake fracture prevention in these patients being treated for locally advanced or high-risk localized disease.

Their analysis was based on a hypothetical model designed to simulate the progression of prostate cancer and the incidence of hip fracture in prostate cancer patients aged 70 years with locally advanced or high-risk localized prostate cancer who were starting a 2-year course of ADT in conjunction with radiation therapy. A more detailed discussion of this paper appeared on Medscape yesterday. The model was built around clinical outcomes data from a variety of studies.

The investigator’s model compared three different management strategies for this hypothetical cohort of patients. The model used alendronate (Fosamax) as the hypothetical form of bisphosphonate therapy. It is a generically available, oral drug which therefore has a relatively low cost in the US. The management options were as follows:

  • No patients would receive BMD tests or bisphosphonate therapy
  • All patients would receive a BMD test and selective bisphosphonate therapy would be given to patients found to have osteoporosis
  • All patients would be given bisphosphonate therapy without any prior BMD testing

The investigators’ model suggested that the second of these strategies was the most cost-effective. However, it should be acknowledged that there is no specific evidence from clinical trials that alendronate reduces actual fracture rates in patients with prostate cancer who receive ADT. Such evidence does exist from other forms of bisphosphonate. It is also not clear whether the use of other forms of bisphosphonate therapy would be as cost effective, nor is it clear whether the costs of dental screening to prevent risks for osteonecrosis of the jaw (a known risk of bisphosphonate therapy) was accounted for in this study.

In their article, Ito et al. go on to state that the routine use of a bisphosphonate such as alendronate may be justifiable without a BMD test in patients at higher risk for hip fractures (e.g., patients who are older than 70 or who have a history of fractures).

The data provided by Ito et al. appear to support a recommendation made by the American College of Physicians (ACP) in 2008. The ACP recommended screening for osteoporosis only in men younger than 80 years of age if they were at increased risk for this condition — and the use of  ADT was identified as a factor that increased such risk.

At the present time, there is considerable evidence that the majority of older patients with prostate cancer who are treated with ADT do not receive either screening or treatment for bone loss, particularly when they are “only” going to receive ADT as adjuvant therapy for a period of time. Even men who are placed on long-term ADT may not be regularly given BMD tests, although this is highly recommended by specialists.

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

This site uses Akismet to reduce spam. Learn how your comment data is processed.

%d bloggers like this: