Androgen deprivation therapy may increase fracture risk in older men with localized prostate cancer: Research

Research presented today at a national conference by a team of investigators at The Cancer Institute of New Jersey (CINJ), shows careful consideration should be given before initiating androgen deprivation therapy, a common treatment for older men with localized prostate cancer. The investigators are concerned that this particular population has a higher than average risk of bone fracture, and that androgen deprivation therapy might add to their fracture risk. For more than a decade, this form of treatment, which shuts off male hormones known to promote growth of prostate cancers, has become a popular alternative to surgery, radiation or conservative management, but little is known about long-term toxic effects associated with its extended use. The work was presented during the Ninth Annual American Association for Cancer Research Frontiers in Cancer Prevention Research Conference in Philadelphia, which runs through tomorrow. CINJ is a Center of Excellence of UMDNJ-Robert Wood Johnson Medical School.

The research utilized information from 46,587 men who were diagnosed with localized prostate cancer (cancer that did not spread beyond the prostate) and survived at least five years after diagnosis. The data were compiled from the population-based Surveillance, Epidemiology, and End Results (SEER) database and linked Medicare files. All of the SEER registries hold the highest level of certification of data quality.

The study found that 48 percent of patients who received androgen deprivation therapy received more than 24 months of treatment. The risk of fracture was nearly one and a half times for men who received 36 or more doses of androgen deprivation therapy (Gonadotropin-releasing hormone agonist) versus those who did not receive any androgen deprivation therapy. Those administered androgen deprivation therapy were associated with a 57 percent increase in the risk of multiple fractures after the first two years of treatment. Men 75 and older who received androgen deprivation therapy, were associated with a fracture risk 3.6 times that of men aged 66 to 74 who had androgen deprivation therapy for less than two years. The authors say it is key to note independent risk factors for fractures including older age, stroke, having two or more diseases at the same time, and history of fractures.

"Because long-term androgen deprivation therapy has become more common for men with localized prostate cancer, it is wise to further explore common adverse effects associated with chronic treatment, including fractures," stated lead author Yu-Hsuan Shao, PhD, a research associate at CINJ. "This is especially important in regard to older men with the disease, since they are already predisposed to a higher fracture risk due to age and other factors."

"There are other viable options out there for older men with localized prostate cancer," said senior author Grace Lu-Yao, PhD, MPH, cancer epidemiologist at CINJ and professor of medicine at UMDNJ-Robert Wood Johnson Medical School and professor of epidemiology at UMDNJ-School of Public Health. "For instance, previous research from our team has shown that older men with low-grade prostate cancer who undergo conservative management are having better survival outcomes than in previous decades, but this route is not often explored. This could be due to a lack of data and clear understanding as to expected outcomes for this population. We are hopeful this latest study will help better shape the conversation between clinician and patient about whether androgen deprivation therapy is the best treatment option for the patient," she said.

Source: The Cancer Institute of New Jersey