Cancer survivors at risk of fractures

Cancer survivors may have an elevated risk of frailty fractures, particularly in the first few years following cancer diagnosis, according to results of a recent study from the US.

“[A] prior cancer diagnosis was associated with the risk of frailty-related fractures, particularly of the pelvis and vertebrae,” said the investigators.

“Cancer survivors who were more recently diagnosed as having a later stage of disease had the highest risk of fracture,” they added.

Utilizing the US Cancer Prevention Study II Nutrition Cohort and Medicare claims data between 1999 and 2017, the investigators analysed the risk of frailty fractures in 92,431 older adults (mean age 69.4 years, 56 percent female, 97.9 percent White). Of these, 14,159 individuals developed cancer during the follow-up period, while 12,943 frailty-related fractures occurred over the follow-up period*.

There was a 57 percent increased risk of frailty-related fractures in cancer survivors in the first year post-diagnosis compared with individuals without cancer (hazard ratio [HR], 1.57, 95 percent confidence interval [CI]1.38–1.79). [JAMA Oncol 2022;doi:10.1001/jamaoncol.2022.5153]

The risk was particularly elevated among cancer survivors who had been diagnosed with distant metastatic cancer 1 to <5 years prior (HR, 2.12, 95 percent CI, 1.75–2.58).

The elevated risk of frailty fracture was primarily due to the more-than-twofold elevated risk of vertebral (HR, 2.46, 95 percent CI, 1.93–3.13) and pelvic (HR, 2.46, 95 percent CI 1.84–3.29) fractures among patients with recent advanced cancer vs no cancer. Conversely, the risk of radial fracture was similar between cancer survivors and those without cancer (HR, 1.09).

This variance in risk by fracture site could be due to different mechanisms of action, such as a higher risk of hip fracture among older individuals who were less active and a higher risk of radial fractures in those who were more active, suggested the investigators.

They cited the importance of ascertaining the reasons behind these differences as cost and morbidity and mortality risk vary by fracture site.

Factors affecting fracture risk

Cancer survivors who received chemotherapy were at an elevated risk of fractures compared with survivors who did not receive chemotherapy, with a greater risk noted among those diagnosed 1 to <5 years prior (HR, 1.31) than ≥5 years post-diagnosis (HR, 1.22).  

The risk of fracture was lower among men without cancer (HR, 0.51) and survivors diagnosed 1 to <5 years prior (HR, 0.53) compared with women in those respective categories, as well as among individuals with BMI ≥ vs <25 kg/m² (HRs, 0.78 and 0.72 for those without cancer and those diagnosed 1 to <5 years prior, respectively). There was also a non-significant reduced risk of fracture among physically active survivors ≥5 years post diagnosis (HR, 0.76).

Fracture risk was higher among current smokers ≥5 years post-cancer diagnosis compared with survivors who were never-smokers (HR, 2.27).

What does this tell us?

“Cancer survivors are at higher risk of bone fractures likely because of higher rates of osteoporosis coupled with low muscle mass, poor balance, and unexpected changes in gait,” said the investigators.

The risk of frailty-related fractures was elevated in the first few years post-cancer diagnosis, but remained higher than that of individuals without a history of cancer even >5 years post-diagnosis, they noted.

The results suggest that clinical guidance on fracture prevention may be helpful for cancer survivors, particularly those with a more recent diagnosis or those who have received chemotherapy.

“If findings from this study are replicated, fracture prevention programmes for survivors might include referrals for physical activity with cancer exercise professionals and for smoking cessation programmes,” they concluded.