Radiation treatment for prostate cancer may increase the risk of patients suffering hip fractures, according to a study presented here at the 2010 American Urological Association (AUA) Annual Meeting.
"Our research suggests that patients treated with 3-dimensional external-beam radiotherapy for prostate cancer could benefit from measures to improve bone health, just as we are doing with androgen-suppression therapy, to decrease the risk of the high morbidity and mortality that occurs with hip fractures," said Sean Elliott, MD, University of Minnesota, Minneapolis, Minnesota, on May 30.
Dr. Elliott and colleagues mined the Surveillance, Epidemiology and End Results (SEER) database and identified 166,162 prostate cancer patients, all of whom were aged 66 years or older. The researchers then compared the rate of hip fractures in patients undergoing radiation therapy with the number of wrist fractures, because radiation therapy for prostate requires radiation to pass through hip bones but does not affect wrists.
After controlling for those who were undergoing androgen-suppression therapy and other risk factors, including osteoporosis, race, and age, the researchers determined that undergoing external-beam radiotherapy increased a man’s risk of hip fracture by 66.5% without increasing the risk of wrist fracture compared with men who underwent radical prostatectomy (P < .001). In fact, the men undergoing external-beam radiation therapy had a slightly decreased risk in wrist fractures compared with men who underwent radical prostatectomy alone, but the difference was not statistically significant.
Patients treated with androgen-suppression therapy alone had an increased risk of both types of fractures. Wrist fractures in these men increased about 70%, and hip fractures increased by 2.5-fold, Dr. Elliott said.
Among men treated with both external-beam radiation and androgen-suppression therapy, the risk of wrist fracture increased about 28%, but the risk of hip fracture increased by more than 2-fold. All of the differences between hip fracture and wrist fracture among those undergoing radiation therapy achieved statistical significance.
"Maintaining bone health is an important part of treating prostate cancer patients, particularly those on aspartate aminotransferase," said AUA spokesman Jeff Holzbeierlein, MD, University of Kansas Medical Center, Kansas City, Kansas.
"These data suggest that we consider taking similar measures with our patients who are receiving 3-dimensional external-beam radiation therapy."