Cognitive Impairments May Affect Survival in Older Patients with Blood Cancer

Cognitive dysfunction among geriatric patients with blood cancers — such as multiple myeloma, leukemia and lymphoma – is not only prevalent, but may also impact long-term survival, according to a study published in JAMA Oncology.

“As the population ages, cognitive impairment is likely to become increasingly common among patients with cancer, diseases that, to a large extent, are associated with aging,” lead study author Tammy Hshieh, M.D., MPH, from Dana-Farber Cancer Institute and Brigham and Women's Hospital, said in a press release.

However, little is known about how specific domains of cognitive impairment may affect survival among older patients with blood cancers.

“Mild changes in memory or thinking may not affect everyday activities, but they can come to the fore in times of stress and affect patients' abilities to care for themselves. We wanted to get a sense of the prevalence of certain types of cognitive impairment and whether they impact survival in older patients with hematologic cancers."

In the prospective, observational cohort study, the researchers identified 420 patients aged 75 and older who presented for initial consultation in the leukemia, myeloma or lymphoma clinics at Dana-Farber from February 2015 to March 2017.

In total, 360 patients underwent physical frailty assessment and took standard screening tests for cognitive impairment in working memory, or the part of short-term memory concerned with immediate perception and executive function — which involves the ability to pay attention, plan, remember instructions and handle multiple tasks successfully.

Assessment tests included the Clock-in-the-Box test, used to screen for executive dysfunction; a five-word delayed recall test, used to screen for impairment in working memory; and the Fried frailty phenotype and Rockwood cumulative deficit model of frailty tests, used to characterize participants as robust, pre-frail, or frail.

The majority of patients were men (64.4 percent) and an average age of 79.8 years.

Screening tests showed that 117 patients (35.5 percent) had probable executive dysfunction and 62 patients (17.2 percent) had probable impairment in working memory. Among these patients, impairment appeared to be modestly correlated with those who were deemed frail or pre-frail.

After evaluating whether cognitive decline affected survival, patients with impaired working memory had worse outcomes (10.9 months vs. 12.9 months) — an 18 percent decrease compared with those without impairments. Similarly, impaired working memory, as well as executive dysfunction, were associated with worse survival among those who underwent intensive treatment, too.

The researchers noted that mild forms of cognitive impairment may not always be obvious to patients and their loved ones. However, when put under stress — such as chemotherapy, feeling unwell from their cancer or medical work-up and tests – patients' cognitive impairment can become more obvious.

“Patients with working memory problems may have difficulty remembering medication schedules or following multiple-step instructions,” Hshieh said. “They may be at risk of becoming dehydrated or not knowing what to do if they experience side effects of treatment.”

Therefore, the findings suggest that screening for specific types of cognitive impairment may be useful in older patients with blood cancer, and that patients found to have such impairments may benefit from tailored explanations and care instructions for individual needs.

“Counseling that acknowledges and anticipates the needs of such patients has a major role,” Hshieh added. “It's important to educate patients about when to call their doctor about a problem, and when to make an appointment to be seen. It's also important for clinicians to take time to explain treatment options to impaired patients and their caregivers to ensure they make choices in line with their values and priorities."