Adding RT to ADT Benefits Older Prostate Cancer Patients

Adding radiotherapy to ADT resulted in fewer deaths in older men with locally advanced prostate cancer.

Older men who received radiation therapy in addition to androgen deprivation therapy (ADT) had fewer deaths from their locally advanced prostate cancer compared with those treated with ADT alone. Researchers analyzed data from two randomized trials and examined whether the benefit was seen in real-world clinical practice results.

Justin E. Bekelman, MD, assistant professor of radiation oncology at the University of Pennsylvania’s Perelman School of Medicine and Abramson Cancer Center, found that the combination of ADT and radiation therapy reduced deaths from prostate cancer by 49% among men between the ages of 76 and 85, compared with men in the same age cohort treated with ADT alone. Deaths from prostate cancer were 9.8% in the ADT alone group compared with 5% in the combination therapy group after a 7-year follow-up.

“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 in a statement.

The results of the study were published in the Journal of Clinical Oncology.

Two recent phase III clinical trials, the SPCG-7/SFUO-3 trial and a National Cancer Institute trial, showed that combining radiation therapy and ADT resulted in reduced all-cause and prostate-specific mortality. The trials reported acceptable side effects. However, according to the authors of the current study, these prior trials excluded elderly patients with screen-detected high-risk disease that has been linked with a substantial mortality risk.

Based on these phase III trials, the American Urological Association and the National Comprehensive Cancer Network recommend that ADT alone should only be offered to those prostate cancer patients who are not eligible for other types of treatment.

Using the Surveillance, Epidemiology, and End Results (SEER)-Medicare database, the authors of the current study analyzed data from 31,541 patients between the ages of 65 and 85. All patients were diagnosed between 1995 and 2007, including those taking part in randomized clinical trials.

Among the men between 65 to 75 years of age, the combination therapy was associated with a 57% reduction in death from prostate cancer. Deaths from prostate cancer were 9.8% in the ADT alone group compared with 4.4% in the combination therapy group after a 7-year follow-up.

In both age cohorts, radiation therapy plus ADT was associated with about 30% fewer any-cause deaths.

“Failure to use effective treatments for older patients with cancer is a healthcare quality concern in the United States. Radiation plus hormone therapy is such a treatment for men with aggressive prostate cancers,” said Bekelman in a statement. “Patients and their physicians should carefully discuss curative treatment options for prostate cancer and reduce the use of hormone therapy alone.”

In an accompanying editorial, Dean A. Shumway, MD, and Daniel A. Hamstra, MD, PhD, of the University of Michigan, point out prior studies showing that men, 75 years of age or older, diagnosed with high-risk prostate cancer received less aggressive treatment compared with their younger counterparts.

“Undertreatment of high-risk prostate cancer is a growing problem, with an increasing use of primary ADT monotherapy over time,” the authors wrote. “Given that an average 75-year-old man in the United States has a remaining life expectancy of 11 years, and that the 10-year cause-specific mortality from conservatively treated high-risk prostate cancer is approximately 26%, this represents a serious potential for age-dependent bias against therapy.”

“In elderly men who are sufficiently healthy to tolerate ADT, careful consideration should be given to also treating with radiation therapy, which is associated with substantial improvements in disease-specific and overall survival and can be delivered with minimal morbidity using modern treatment techniques,” concluded Shumway and Hamstra.