SAN FRANCISCO—Men who undergo three-dimensional external beam radiotherapy (3D-EBRT) for prostate cancer may be at elevated risk for hip fractures, according to researchers.
Using 1992-2005 data from the Surveillance Epidemiology and End Results (SEER)-Medicare database, Sean Elliott, MD, and colleagues at the University of Minnesota in Minneapolis identified 49,858 prostate cancer patients aged 66 years and older.
To test a hypothesis that 3D-EBRT is a risk factor for hip fracture but not fractures outside of the radiation field, they compared the cumulative incidence of hip and wrist fractures in men who underwent radical prostatectomy (RP), EBRT, EBRT plus androgen suppression therapy (AST), or AST alone. The mean follow-up period was five years.
Compared with patients treated with RP, EBRT-treated men had a significant 67% increased risk for hip fracture, but did not have an increased risk for wrist fracture, after controlling for AST, age, race, osteoporosis, and other comorbidities.
Men treated with AST had a 152% increased risk of hip and 69% increased risk of wrist fractures. A combination of EBRT and AST was associated with a twofold increased risk of hip fracture, higher than the risk associated with EBRT alone but less than AST alone. This is likely due to the fact that men received fewer AST doses when this AST was combined with EBRT.
Dr. Elliott, who presented study findings at the American Urological Association annual meeting, concluded that men treated with 3D-EBRT for prostate cancer could benefit from measures to improve bone health.