Two Studies Explore Role of Radiation, Bisphosphonates in Prostate Cancer Care

Justin E. Bekelman, MD

For older men with prostate cancer, adding radiation to hormone therapy is both tolerable and effective in reducing the number of deaths, according to results of a new study by researchers at Penn Medicine, suggesting that the current gap in curative cancer care for baby boomers aging into their 70s might be bridged by more thorough provider—patient discussions of treatment options.

“Failure to use effective treatments for older patients with cancer is a healthcare quality concern in the United States,” lead study author Justin E. Bekelman, MD, an assistant professor of Radiation Oncology, Medical Ethics and Health Policy at Penn’s Perelman School of Medicine and Abramson Cancer Center, said in a statement. “Patients and their physicians should carefully discuss curative treatment options for prostate cancer and reduce the use of hormone therapy alone.”

Although two landmark clinical trials have shown that radiation plus hormone therapy produces a large and significant improvement in survival in younger men relative to hormone therapy alone, there has been no comparable research on treatment for older men with advanced prostate cancer.

For this study, researchers used the SEER Medicare database to compare the combination of radiation plus hormone therapy versus hormone therapy alone in 31,541 men aged 65 to 85 years diagnosed with prostate cancer between 1995 and 2007. Among men aged 65 to 75 years, radiation plus hormone therapy was associated with a reduction in prostate cancer deaths of 57% relative to hormone therapy alone (from 9.8% to 4.4% of patients at 7 years follow up).¹

Similarly, among men aged 76 to 85 years, radiation plus hormone therapy was associated with a reduction in prostate cancer deaths of 49% relative to hormone therapy alone (from 9.8% to 5% of patients at 7 years follow-up).

In both of the cohorts, radiation plus hormone therapy also was associated with about one-third fewer deaths from any cause.

Importantly, the researchers noted, the side effects of radiation plus hormone therapy are very acceptable relative to hormone therapy alone. “Older men with aggressive prostate cancers should know that the combination of radiation plus hormone therapy is both tolerable and effective in curing prostate cancer,” said Bekelman.

Bone-Strengthening Drugs With ADT

In another study, researchers in Toronto have found that despite being recommended to promote bone health, the use of bisphosphonates remains low in men receiving androgen-deprivation therapy (ADT) for prostate cancer, and this is true even for those at high risk of subsequent fractures.²

A total of 35,487 men aged ≥66 with prostate cancer who initiated therapy with ADT between 1995 and 2012 were identified using databases at the Institute for Clinical Evaluative Services and the Ontario Cancer Registry. Any bisphosphonate claim within 12 months of ADT initiation was captured through drug database claims. Bisphosphonate prescriptions over time were examined for three groups: all nonusers of bisphosphonates, those with prior osteoporosis, and those with prior fragility fracture.

Bisphosphonate claims among all nonusers increased from 0.35 per 100 persons in 1995-1997 to 3.40 per 100 persons in 2010-2012. Even among those with prior osteoporosis or fragility fracture, rates remained low. Among all 3 groups, peak bisphosphonate claims occurred in 2007-2009, with a high of 11.89 per 100 persons in those with prior osteoporosis.

As the most widely used class of prescription drugs for osteoporosis, the authors wrote that these findings suggest “limited awareness among clinicians regarding optimal bone health management.”

References

• Bekelman JE, Mitra N, Handorf EA, et al. Effectiveness of androgen-deprivation therapy and radiotherapy for older men with local advanced prostate cancer [published online ahead of print January 5, 2015]. J Clin Oncol.
• Gulamhusein H, Yun L, Cheung AM, et al. Bisphosphonate prescriptions in men with androgen deprivation therapy use. JAMA. 2014;312(21):2285-2286.