“Anemia was highly prevalent and independently associated with functional disability” among older adults with cancer, according to an analysis of data conducted by Cynthia Owusu, MD, MS, of Case Western Reserve University, Cleveland, and colleagues. “Older patients with anemia were more than twice as likely to have functional disability than those without anemia,” the investigators reported in the Journal of the National Comprehensive Cancer Network.
An assessment of the association between anemia and activities of daily living among older adults with cancer “is clinically relevant,” the authors noted, because Eastern Cooperative Oncology Group (ECOG) performance status and Karnofsky performance scale “may underestimate the extent of functional impairment among older adults, and self-reported activities of daily living and instrumental activities of daily living present a more comprehensive approach for assessing the functional status of older adults with cancer.” It is in this context that the researchers sought to examine the association between anemia and functional disability (the need for assistance with at least one instrumental activity of daily living) among a cohort of older adults with cancer.
Needed Assistance With at Least One Activity
The researchers conducted a cross-sectional analysis of data derived from a multicenter prospective study that identified clinical and biologic predictors of chemotherapy among 500 patients with cancer who were aged 65 years or older. The patients were recruited from ambulatory oncology clinics at seven institutions.
The median age of the 491 evaluable patients was 73.1 years (range, 65–91 years); 85% were white, and 56% were female. The most common types of cancer were lung (28.5%), gastrointestinal (27.1%), gynecologic (17.3%), breast (11.4%), and genitourinary (10.2%). Most patients (61.5%) had stage IV disease, and 44% had three or more comorbidities.
“The primary outcome was functional disability at chemotherapy initiation, defined as the need for assistance with at least one instrumental activity of daily living. Anemia (using World Health Organization criteria) was defined as a hemoglobin level of less than 12 g/dL in women and less than 13 g/dL in men,” the investigators explained.
‘Consistent and Robust Association’
Functional disability was present in 43% of patients and anemia, in 51%. “On multivariable analysis, adjusting for sex, stage, and unintentional weight loss, patients with anemia were more likely to have functional disability (odds ratio, 2.40; 95% confidence interval, 1.61–3.59),” the researchers found. Patients with anemia also had lower scores for instrumental activities of daily living and other physical functioning scales. “These results demonstrate a consistent and robust association between anemia and physical function, irrespective of whether physical function is patient self-reported or provider-rated,” the investigators stated.
The researchers called for longitudinal studies among older adults with cancer to help in establishing a causal link between anemia and functional disability and randomized controlled trials to evaluate whether treating anemia can improve functional status and treatment tolerance among older adults with cancer. “Although 30% of all anemia in older adults may be unexplained, and therefore is not readily corrected, and the use of erythropoietin in patients with cancer may be associated with increased mortality and is therefore not recommended by current guidelines, a significant proportion of anemia in older adults is caused by nutritional deficiencies and is readily modifiable,” the authors wrote. “Modifiable causes of anemia offer an opportunity to evaluate whether treating anemia can improve functional status and treatment tolerance among older adults with cancer.” ■
Owusu C, et al: J Natl Compr Canc Netw 13:1233-1239, 2015.