Fracture risk and initiation of bone-specific drug therapy following radical cystectomy with urinary diversion.

Objectives

To assess the risk of fractures among patients with bladder cancer who underwent radical cystectomy (RC) with urinary diversion (UD), compared with matched referents from the general population.

Patients/subjects and methods

We identified 2908 patients who underwent RC between 2011 and 2019, and 13 669 matched referents in a nationwide, register-based Swedish cohort study. Outcomes were femoral fracture, any fracture, and initiation of bone-specific drug therapy (BDT). Cumulative incidence was estimated using competing-risk analyses, and hazard ratios (HRs) were derived from multivariable Cox models stratified by sex. Additional analyses were conducted among patients with muscle-invasive bladder cancer treated with curative radiotherapy (n = 328).

Results

Compared to referents, RC with UD was associated with a higher cumulative incidence of fractures. Women had an increased risk of femoral fracture (HR 1.97, 95% confidence interval [CI] 1.25-3.10) and any fracture (HR 2.06, 95% CI 1.54-2.76), while men had an increased risk of any fracture (HR 1.51, 95% CI 1.22-1.88). No association was observed for initiation of BDT in either sex. In the additional cohort, men treated with radiotherapy had an increased risk of any fracture (HR 2.14, 95% CI 1.26-3.62), whereas estimates for women were imprecise.

Conclusion

Patients undergoing RC with UD experienced increased fracture risks, particularly women. Additional analyses suggest that fracture risk may be influenced by factors related to both bladder cancer and its treatment, although the strongest and most consistent associations were observed following RC with UD. These findings support increased attention to bone health in these patients.