Real World Outcomes in Patients With Metastatic, Castration-Resistant Prostate Cancer Treated With Radium-223 in Routine Clinical Practice in Sweden

Clin Genitourin Cancer. 2023 Feb;21(1):107.e1-107.e9. doi: 10.1016/j.clgc.2022.09.002. Epub 2022 Sep 9.

Abstract

Aim: Estimate the effect of Radium-223 (Ra-223) on the incidence of bone fractures, prostate cancer death, and all-cause death compared with other standard treatments for metastatic, castration-resistant prostate cancer (mCRPC).

Methods: Using a cohort design, we estimated the effect of Ra-223 on the risk of bone fractures, all-cause and prostate cancer-specific mortality across different lines of treatment for mCRPC using Prostate Cancer data Base Sweden (2013-2018). The comparator group comprised other standard treatments for mCRPC. We used 36-month risk differences and hazard ratios (HRs) as effect estimates.

Results: The number of eligible individuals was 635, 453, 262, and 84 for the first-, second-, third-, and fourth-line cohorts, respectively. When compared Ra-223 to other standard treatments, the difference in the 36-month risk of fracture was 6% (95% confidence interval [CI], -7% to 18%) in the first-line cohort (n = 635) and 8% (95% CI, -7% to 18%) in the second-line cohort (n = 453). The number of fractures in the third-/fourth-line cohorts was too small for an adjusted comparison. The difference in 36-month mortality was higher in the first-line cohort 13% (95% CI, -3% to 31%), but lower in the second- and third-/fourth-line cohorts-8% (95% CI, -23% to 7%) and -14% (95% CI, -21% to 16%) respectively. Most deaths were due to prostate cancer.

Conclusion: Results suggest that the difference in the risk of fractures is small, if any. A difference in the risk of mortality may be present in first-line treatment, but a decreased risk of mortality was observed in second and later lines of treatment. The results on mortality need to be considered in the context of potential unmeasured or residual confounding.

Keywords: Fracture; Lines of treatment; Observational study; Safety.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Bone Neoplasms* / drug therapy
  • Bone Neoplasms* / radiotherapy
  • Fractures, Bone* / chemically induced
  • Fractures, Bone* / drug therapy
  • Humans
  • Male
  • Prostatic Neoplasms, Castration-Resistant* / drug therapy
  • Radium* / therapeutic use
  • Retrospective Studies
  • Sweden / epidemiology

Substances

  • Radium-223
  • Radium