A new index of frailty predicts survival in older patients with multiple myeloma based on accumulation of aging-associated deficits, rather than chronological age alone, investigators report. A 16% increased risk of death was seen for each 10% increase in the deficit-accumulation frailty index (DAFI), which includes 25 variables related health, function, and activities of daily living.
There was only a weak correlation between chronological age and increase in deficits tracked by the index, in contrast to a cohort without cancer, in which age and frailty were strongly correlated, the investigators reported in JCO Clinical Cancer Informatics.
“Our results demonstrate that, for patients with multiple myeloma, chronological age alone is not a good measure for assessing overall health,” study author Tanya M. Wildes, MD, of Washington University, St. Louis, said in a news release from the American Society of Clinical Oncology.
Existing tools to assess frailty include an index proposed by the International Myeloma Working Group that looks at age plus other indexes related to comorbidities and activities of daily living, and the revised Myeloma Comorbidity Index that incorporates age with other prognostic factors.
“Although both tools provide prognostic information, chronological age automatically increases frailty without taking biologic or functional age into account,” Dr. Wildes and her coauthors wrote in their report.
By contrast, the DAFI is based on the concept of biologic age, in which the health status of an individual is measured based on the proportion of aging-associated deficits they have accumulated, according to the authors.
To create the DAFI, Dr. Wildes and her colleagues analyzed nearly 2.7 million records of noncancer patients aged 66 years or older in the SEER Medicare Health Outcomes Survey (MHOS) database. They identified 25 variables in the database representing chronic health conditions, activities of daily living, functioning, mental health, and general health.
An individual’s DAFI score was calculated as the sum of scores for each of the 25 variables as 0 for absent, 0.5 for limited, and 1 for present. Predicted DAFI means were calculated for each year of age and used to create age-specific cut points to determine whether an individual would be considered frail or not versus others of the same age.
“In other words, the same frailty score may qualify an 80-year-old individual as fit and a 70-year-old as frail, depending on the cutoff for their respective age group,” investigators explained in their report.
They applied the index to 305 patients with newly diagnosed myeloma in the SEER-MHOS database who were 66 years of age or older (median age, 76 years) and had completed the survey within 1 year of diagnosis.
The DAFI classified 52% of the myeloma patients as frail, and for that group, median overall survival was 26.8 months, versus 43.7 months for nonfrail patients (P = .015), according to the reported data. For each 10% increase in score, the risk of death increased by 16% (P less than .001).
Notably, advancing age was very weakly correlated with increased age-related deficits in the myeloma cohort (r2 = 0.15; P = .010), according to investigators, but very strongly correlated with deficits in the cohort of noncancer patients (r2 = 0.98; P less than .001).
“This suggests that, in patients with multiple myeloma, the prevalence of impairments across domains of function, chronic comorbidities, general health, and mental health are more related to the overall burden of myeloma rather than chronological age alone,” the investigators wrote.
The information used to calculate a DAFI score is easily obtainable during a clinic visit, according to the authors, who provided an overview of all 25 variables in the journal article.
Further development of a computerized program would further enhance usability in the clinic, allowing for real-time calculation during a patient visit, they said.
Survivorship expert Merry Jennifer Markham, MD, said in the ASCO news release that this frailty index is notable because it accounts for more than just chronological age. “Knowing this information can help oncologists have more informed discussions with patients about their prognosis, which in turn can empower patients and families as they weigh treatment options,” she said.
The research was supported by National Cancer Institute. Dr. Wildes reported honoraria from Carevive Systems and research funding from Janssen Oncology. Another coauthor reported honoraria from Celgene and Janssen, and a consulting or advisory role with Amgen and Takeda.
SOURCE: Mian HS et al. JCO Clin Cancer Inform. 2018 Jul 25. 2018 Jul 25. doi: 10.1200/CCI.18.00043.