Functional Assessment of the Older Patient With Cancer

Other Geriatric Issues Important to Cancer Treatment

As previously described, older adults constitute a complex population with considerable variability in degree of wellness and ability to tolerate cancer treatment. Just examining functional ability with one of the tests mentioned will not give a complete picture. Issues such as memory impairment, malnutrition, and depression, often referred to as “geriatric syndromes,” are also prevalent in older adults and should be considered as well.

Cognitive Function

Cognitive impairment and dementia are diseases that predominantly strike older adults. In studies where comprehensive geriatric assessments were conducted in older patients with cancer, as many as 25% to 50% of the subjects screened positive for cognitive abnormalities.[5] However, a positive screen for cognitive impairment does not diagnose dementia; further testing and work-up are recommended. If a patient screens positive for memory impairment, referral to geriatrics, neurology, or psychiatry should be considered.

Previous studies have demonstrated an association between physical and cognitive function in older adults.[18-21] Fitzpatrick and colleagues studied 3,035 healthy older adults with a mean age of 78.6 and found an association between low cognitive score on the Modified Mini-Mental Status exam and the slowest quartile on a walking test.[20] Coppin and colleagues studied 737 older adults, mean age 72.7, and found an association between poor executive function and slow gait speed.[21] In the Women's Health and Aging Study, difficulties in executive function were associated with slower performance on tasks of higher-order IADLs.[22]

Other studies have demonstrated that changes in cognitive status are associated with longitudinal changes in physical function and subsequent disability. The MacArthur Research Network on Successful Aging Community Study evaluated changes in physical and cognitive function over a 7-year period in a cohort of high-functioning older adults. This study found that declines in cognitive function were associated with declines in routine physical tasks such as walking at a normal pace, as well as demanding physical tasks such as standing on one leg.[19] In a community-based longitudinal study of 977 individuals aged < 65, cognitive status predicted functional limitations (upper and lower body) as well as disability in ADLs. Atkinson and colleagues studied 2,349 older adults, mean age 75.6, and found that global and executive cognitive function predicted declines in gait speed.[23]

• Implications for Cancer Patients—Cognitive function has significant practical implications for a patient receiving cancer therapy. In the presence of memory impairment, the patient will have difficulty understanding and remembering treatment instructions, potentially affecting compliance with oral cancer therapy or supportive medications. Patients with cognitive impairment may have difficulty remembering the signs and symptoms of cancer or cancer therapy side effects that warrant medical attention, or may have trouble remembering appointments. In more advanced cases of dementia, the capacity of patients to make decisions regarding treatment also becomes problematic. These issues help explain the association of dementia with increased mortality across all older populations.[24] Identifying and enlisting the patient's social support network or community-based support systems (such as a visiting nurse) are critical in optimizing results and minimizing complications from cancer therapy.

A second issue with cognitive complaints in older adults with cancer is the current lack of understanding of whether the cognitive problem is from a preexisting condition or if it is cancer- or cancer therapy–related. Complaints of cognitive dysfunction following cancer treatment have been described, particularly among breast cancer survivors. However, few studies have specifically focused on the association between cancer therapy and cognitive function in older adults or those with preexisting cognitive problems.[25,26] A recent review of published studies did not conclusively show an association between cancer treatment and subsequent development of dementia.[27] This deserves further research because of its important survivorship implications.

Simple, valid screening tests for cognitive impairment include the Mini-Mental Status exam.[28] Other shorter screening tests include the Six-item Screener,[29] the Clock-Draw test,[30] and the Blessed Orientation-Memory-Concentration test.[31]