BOSTON — With an aging population, cognitive impairment is increasingly common. The question raised by a new study was what effect that has on survival for older patients with hematologic cancers.

A study group involving the Boston VAMC sought to determine the prevalence of domain-specific cognitive impairment and its association with overall survival among older patients with blood cancer.

For the prospective observational cohort study published in JAMA Oncology, researchers focused on a group of patients 75 years and older who presented for initial consultation in the leukemia, myeloma or lymphoma clinics of a large tertiary hospital in Boston from Feb. 1, 2015, to March 31, 2017. All participants were screened for frailty and cognitive dysfunction and then were followed up for survival.1

Among the evaluations used were the Clock-in-the-Box (CIB) test to screen for executive dysfunction and a five-word delayed recall test to screen for impairment in working memory. At the same time, the Fried frailty phenotype and Rockwood cumulative deficit model of frailty were also assessed to characterize participants as robust, prefrail or frail.

Among 420 consecutive patients approached, 360 (85.7%) agreed to undergo frailty assessment (232 men [64.4%] and 128 women [35.6%]; mean [SD] age, 79.8 [3.9] years), and 341 of those (94.7%) completed both cognitive screening tests. Researchers determined that 127 patients (35.3%) had probable executive dysfunction on the CIB, and 62 (17.2%) had probable impairment in working memory on the five-word delayed recall.

Results indicated that impairment in either domain was modestly correlated with the Fried frailty phenotype (CIB, ρ = 0.177; delayed recall, ρ = 0.170; P = .01 for both), and many phenotypically robust patients also had probable cognitive impairment (24 of 104 [23.1%] on CIB and 9 of 104 [8.7%] on delayed recall).

The study team demonstrated that patients with impaired working memory had worse median survival (10.9 [SD, 12.9] vs 12.2 [SD, 14.7] months; log-rank P <.001); that persisted even when stratified by indolent cancer (log-rank P = .01) and aggressive cancer (P < .001) and in multivariate analysis when adjusting for age, comorbidities and disease aggressiveness (odds ratio, 0.26; 95% CI, 0.13-0.50).

The study found that impaired working memory was also associated with worse survival for those undergoing intensive treatment (log-rank P < .001). Executive dysfunction was associated with worse survival only among patients who underwent intensive treatment (log-rank P = .03), the article noted.

“These data suggest that domains of cognitive dysfunction may be prevalent in older patients with blood cancer and may have differential predictive value for survival,” study authors concluded. “Targeted interventions are needed for this vulnerable patient population.”

1Hshieh TT, Jung WF, Grande LJ, Chen J, Stone RM, Soiffer RJ, Driver JA, Abel GA. Prevalence of Cognitive Impairment and Association With Survival Among Older Patients With Hematologic Cancers. JAMA Oncol. 2018 Mar 1. doi:10.1001/jamaoncol.2017.5674. [Epub ahead of print] PubMed PMID: 29494732.