Fractures and long-term mortality in cancer patients: a population-based cohort study

Abstract

We assessed post-fracture mortality in a population-based cohort of 122,045 individuals with cancers. Major fractures (hip, vertebrae, humerus, and forearm) were associated with early and long-term increased all-cause mortality.

Introduction: Currently, there are no population-based data among cancer patients on post-fracture mortality risk across a broad range of cancer diagnoses. Our objective was to estimate the association of fracture with mortality in cancer survivors.

Methods: Using Manitoba Cancer Registry data from the province of Manitoba, Canada, we identified all women and men with cancer diagnosed between January 1, 1987, and March 31, 2014. We then linked cancer data to provincial healthcare administrative data and ascertained fractures after cancer diagnosis and mortality to March 31, 2015. Hazard ratios for all-cause mortality in those with versus without fracture were estimated from time-dependent Cox proportional hazards models adjusted for multiple covariates.

Results: The study cohort consisted of 122,045 cancer patients (median age 68 years, IQR 58-77, 49.2% female). During the median follow-up of 5.8 years from cancer diagnosis, we ascertained 7120 (5.8%) major fractures. All fracture sites, except for the forearm, were associated with increased mortality risk, even after multivariable adjustment. Excess mortality risk associated with a major fracture was greatest in the first year after fracture (HR 2.42, 95% CI 2.30-2.54) and remained significant > 5 years after fracture (HR 1.60, 95% CI 1.50-1.70) and for fractures occurring > 10 years after cancer diagnosis (HR 1.93, 95% CI 1.79-2.07).

Conclusion: Fractures among cancer patients are associated with increased all-cause mortality. This excess risk is greatest in the first year and persists more than 5 years post-fracture; increased risk is also noted for fractures occurring up to and beyond 10 years after cancer diagnosis.

Keywords: Cancer; Fracture; Mortality; Osteoporosis.