Increased Risk of Fracture After Radical Cystectomy and Urinary Diversion in Older Patients With Bladder Cancer
In a population-based study reported in the Journal of Clinical Oncology, Gupta et al found that radical cystectomy with urinary diversion for bladder cancer is associated with increased risk of bone fracture at any site in Medicare patients. Radical cystectomy and urinary diversion may cause chronic metabolic acidosis and associated long-term bone loss.
Study Details
The study involved analysis of linked Surveillance, Epidemiology, and End Results (SEER) and Medicare data from 2000 through 2007 for 50,520 patients aged > 65 years with stage 0 to III bladder cancer. Of these, a total of 4,878 (10%) underwent cystectomy and urinary diversion. Patients undergoing cystectomy and urinary diversion were younger, less likely to have comorbidities, history of chronic kidney disease, and history of fracture, and more likely to have more-advanced disease stage and grade and to have received systemic chemotherapy (all P < .001).
Fracture Risk
During median follow-up of 41 months, 10,872 patients (22%) had a fracture, including 792 (16%) of those who had undergone cystectomy and urinary diversion and 10,080 (22%) of those with no cystectomy. Median time to fracture was 16.6 months from cystectomy in the cystectomy group and 21.8 months from cancer diagnosis in the no cystectomy group. Fracture incidence rate was 6.55/100 person-years vs 6.39/100 person-years. Sites of fracture did not markedly differ between groups.
In unadjusted analysis, fracture-free survival was better in the patients who had received cystectomy. In analysis controlling for patient, disease, and health characteristics, the cystectomy group had a significantly increased risk of fracture (adjusted hazard ratio [HR] = 1.21, P < .001).
On adjusted analysis, risk for fracture was also significantly increased (all P <.001) in older patients, women (HR = 1.61), white patients, unmarried patients, those who had received no chemotherapy, and those with higher disease stage, higher comorbidity score, history of chronic kidney disease, and history of fracture (HR = 2.97). There was no evidence of an interaction between radical cystectomy and age, sex, comorbidity score, or cancer stage.
The investigators concluded: “[W]e found that radical cystectomy and urinary diversion were associated with an increased risk of fracture in older patients with bladder cancer. These findings emphasize the need to monitor bone health and to conduct trials of prophylactic therapies that may reduce the risk of fracture in these patients.”
Amit Gupta, MD, MPH, of University of Iowa, is the corresponding author for the Journal of Clinical Oncology article.
The study was supported by an award from the National Cancer Institute. The study authors reported no potential conflicts of interest.
The content in this post has not been reviewed by the American Society of Clinical Oncology, Inc. (ASCO®) and does not necessarily reflect the ideas and opinions of ASCO®.
