Despite the perceived benefits of their use in guiding treatment, frailty indexes were not reliable in differentiating elderly multiple myeloma (MM) patients, according to an analysis of a prospective cohort of 40 patients studied at a single institution.
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The researchers examined three different models of frailty using data available in the Cancer and Aging Research Group tool to define frailty in their cohort: the international myeloma working group (IMWG) frailty model, the revised myeloma comorbidity index (R-MCI), and the Carolina Frailty Index (CFI).
The researchers found that, for their same population, applying the IMWG frailty index yielded 3 (7.5%) patients categorized as fit, 15 (37.5%) categorized as intermediate fit, and 22 (55%) categorized as frail. The R-MCI yielded 4 (10%) patients categorized as fit, 29 (72.5%) as intermediate, and 7 (17.5%) as frail. When using the CFI, 17 (42.5%) patients were categorized as fit, 8 (20%) were intermediate, and 15 (37.5%) were frail. Of particular note, among 28 patients categorized as frail by at least one of the three indexes, only 3 (11%) patients were categorized as frail by all three models.
The reasons for the differences were discussed by the authors, who pointed out that patients categorized as frail by the IMWG or R-MCI tended to be older than those categorized as frail by CFI, reflecting the fact that the IMWG and R-MCI both include age as a component of frailty, while the CFI does not. In addition, each index incorporates comorbidities into its assessment of frailty in a different way.
For example, falls and depression are incorporated as components of the CFI, reflected in the higher proportion of patients reporting a prior fall and more symptoms of depression in the group categorized as frail by the CFI model than in the IMWG or R-MCI. In the CFI as well, each of the individual instrumental activities of daily living is a component of the model, rather than the summary score, as in the IMWG and R-MCI.
“Our findings highlight the differences in currently available approaches to applying the concept of frailty to older adults with cancer. This problem is not unique to oncology, as there is a continued lack of consensus on defining the concept of frailty in the general geriatric population,” the researchers stated. “Further studies are needed to establish the role of frailty indexes in predicting toxicity of therapy and other outcomes of importance in older adults with multiple myeloma,” they concluded.
The study was funded by the National Cancer Institute and other U.S. government agencies. The authors reported having no conflicts.
SOURCE: Isaacs A et al. J Geriat Onc. 2020;11(2):311-15.