MADRID – The risk of osteoporotic fracture associated with hematopoietic stem cell transplantation (HSCT) could be assessed using the Fracture Risk Assessment Tool (FRAX), researchers from the University of Texas MD Anderson Cancer Center have found.
In a retrospective cohort study, Huifang Lu, MD, and her collaborators found that FRAX could predict the risk of fracture with reasonable accuracy. The area under the receiver operating characteristic curve was 0.66 for predicting a fracture 10 years after HSCT.
“Current guidelines recommend the evaluation of bone health at 1 year following the transplant, but we recommend that this needs to happen at a much earlier time,” Dr. Lu said at the European Congress of Rheumatology.
Determining how to assess risk earlier and prevent bone loss remains a challenge, however. FRAX is an easy and quick tool to use, but its predictive ability is modest, she said.
As the finding comes from a retrospective study, prospective evaluation of FRAX is needed in HSCT patients. If shown predictive in this setting, bone health could be assessed earlier using FRAX, ideally at or before the time of the transplant, to allow appropriate action to be taken, such as prescribing bisphosphonates to those identified to be at high risk.
There is no consensus on preventing and treating bone loss following HSCT, said Dr. Lu. In a meta-analysis performed by Dr. Lu and her associates (Bone Marrow Transplant. 2017;52[5]:663-70), less bone loss was seen in patients who received a bisphosphonate.
As the use of HSCT has expanded over the past two decades, there is an expanding population of survivors with potential long-term effects such as bone loss and a higher risk of fractures, compared with the general population, Dr. Lu explained.
The FRAX tool takes into account pre-HSCT factors such as age, smoking status, alcohol use, prior fracture, body mass index, and corticosteroid use. This can be considered in association with the fracture risk related to the various conditioning and supporting regimens that patients receive around the time of their transplants.
The study included 5,170 adult patients who had undergone HSCT at the University of Texas MD Anderson Cancer Center over a 10-year period. Patients were considered to have entered the cohort at the time of their transplants, Dr. Lu said. Their history of osteoporotic fractures up to 3.3 years later was obtained and verified by radiology and physician assessment. FRAX probabilities were then derived from baseline information.
The mean age of patients included was 52 years, 57% were male and 75% were white. One-quarter had experienced a prior fracture. Of note, 26% of the cohort underwent HSCT for multiple myeloma, 70% of whom had already had a fracture, compared with 9% of those who underwent HSCT for another reason such as leukemia or lymphoma.
Multivariate analyses were performed with and without considering death as a competing risk, and similar results were obtained. Higher FRAX scores (20 or greater) were more likely to be recorded in individuals who sustained a fracture than in those who did not. Patients who had an allogeneic HSCT were 15% more likely to have a fracture as those who received an autologous transplant. Perhaps not surprisingly, patients with multiple myeloma were more likely than those who had HSCT for other reasons to sustain a fracture by 10 years based on FRAX results (hazard ratio, 3.16).
Future research needs to look at the optimal cut offs for FRAX scores predictive of events and see if there is any association between the loss of bone and fracture risk. There also needs to be an evaluation of the use of concomitant medications and health economic analyses performed.
Dr. Lu had no conflicts of interest. The study was funded by the Rolanette and Berdon Lawrence Bone Disease Program of Texas and via Cancer Survivorship Research Seed Monday Grants from the University Cancer Foundation and Duncan Family Institute for Cancer Prevention and Risk Assessment to the University of Texas MD Anderson Cancer Center.