Exploration of risk factors for osteoporotic fracture following hematopoietic stem cell transplantation.

Abstract

10080 Background: The incidence of fractures following hematopoietic stem cell transplantation (HSCT) ranges from 5% to 12% and the rates are up to 10 times greater than in the general population. The risk factors involved in osteoporotic fracture development following HSCT are incompletely understood. Methods: We conducted a retrospective cohort study of patients > 18 years that received a HSCT at MD Anderson Cancer Center, from January 1, 2001 to December 31, 2010. Patients were followed until December 31, 2013 for assessment of osteoporotic fracture occurrence using ICD-9 codes and confirmed by chart review. Cox regression model was used to identify independent risk factors for osteoporotic fractures. Factors included individual risk factors included in the World Health Organization Fracture Risk Assessment Tool FRAX and type of HSCT, type of preparatory regimen and underlying indication for HSCT. Results: A total of 5,170 patients received a HSCT during the 10-year study period, of which 527 (10%) patients developed an osteoporotic fracture. The median time of follow up was 3.2 years. A multivariate Cox regression model considering all clinical and malignancy specific risk factors was fitted. With the control of all other variables, the risk of developing fracture was 1.20 (95% confidence interval (CI):1.02-1.41) times higher for every 20 years increase in age at HSCT; female patients had a 1.24 (95% CI: 1.05-1.48) times higher risk compared to male patients; patients with a fracture prior to HSCT had a 2.01 (95% CI: 1.62-2.51) times higher risk compared to patients without a prior fracture; patients receiving an allogeneic HSCT had a 1.57 (95% CI: 1.20-2.05) times higher risk compared to patients receiving an autologous HSCT; and patients with multiple myeloma had a 2.62 (95% CI: 1.97-3.49) times higher risk compared to patients without multiple myeloma. Conclusions: Age at HSCT, gender, prior fracture status, type of HSCT, and underlying indication were identified to be statistically significantly associated with fracture. This is one of the first large scale studies assessing a comprehensive set of risk factors. To develop a risk model for fracture, we should consider these factors.