Clinical Geriatrics

To the Editor:
I read with interest the article, “Osteoporosis in Elderly Men,”1 written by Neil Baum, MD. The initial background information is pertinent and raises awareness of the growing problem of osteoporosis in men, and a number of preventive and management strategies are suggested. The case presented in the article is a 66-year-old man with a history of prostate cancer that was initially treated with radiation therapy. After a recurrence of cancer, he was treated with luteinizing hormone-releasing hormone agonist and anti-androgen therapy, which is an important risk factor for accelerated bone loss in men. When a bone density test was finally done (after height loss, lethargy, and falling asleep after meals) osteoporosis was documented by dual energy x-ray absorptiometry (DEXA). He was then treated with teriparatide (rHPTH, 1-34) daily injections.

Teriparatide is an anabolic agent that is FDA-approved for use in men and postmenopausal women that stimulates bone formation, unlike the anti-catabolic agents approved for osteoporosis treatment in men (alendronate and risedronate). Teriparatide has a “black box” warning about the increase in bone tumors in a rat model given high doses of this agent. Because external beam radiation has a known potential for increasing bone cancer, this drug is contraindicated in an adult with a history of prior external beam radiation exposure. We also know that the anti-catabolic class of osteoporosis agents is used to treat and also prevent bone metastasis in men with prostate cancer, so using an agent that acts completely opposite this action poses an unknown but potential increased risk.

I think it is admirable that the urology community is becoming more vigilant about diagnosing and treating osteoporosis with their captive population of older men with prostate cancer. However, my suggestion is that in a case such as this, there should be earlier thought given to progressive bone loss from aging, prostate cancer, and androgen-deprivation therapy and preventive measures taken. This would include bone density testing with DEXA upon diagnosis, assuring adequacy of calcium, satisfactory vitamin D level (≥ 30 ng/mL), and use of bisphosphonate therapy, either oral or intravenous, if not contraindicated.

Sincerely,
Christine Simonelli, MD
Director, HealthEast Osteoporosis Care
Woodbury, MN;
Associate Clinical Professor of Medicine
University of Minnesota
Minneapolis, MN

Reference
1. Baum N. Osteoporosis in elderly men. Clinical Geriatrics 2007;15(5):29-33.

Dr. Baum responds:

I am in agreement with the comment that bisphosphonate therapy is also an effective therapeutic option in men with prostate cancer who have osteoporosis treated with hormone replacement therapy. I also agree that bisphosphonates may be a better therapeutic option, especially in patients with other medical conditions including adenocarcinoma of the prostate gland.

I reported on this patient as an example to increase awareness of other treatment options for osteoporosis in men.

It is of interest that in this sarcoma-rat model, these animals received supraphysiologic doses of teriparatide, and I am unaware of any clinical reports of this malignancy (ie, sarcoma) occurring in men receiving therapeutic doses of teriparatide.

Sincerely,

Neil Baum, MD
Clinical Associate Professor of Urology
Tulane Medical School
New Orleans, LA

Mario McNally, MD
Clinical Professor of Medicine (Endocrinology)
Tulane Medical School
New Orleans, LA