Do Patients With Advanced Cancer Have the Ability to Make Informed Decisions for Participation in Phase I Clinical Trials?

Abstract

Purpose Patients with advanced cancer (ACPs) participating in phase I clinical trials inadequately understand many elements of informed consent (IC); however, the prevalence and impact of cognitive impairment has not been described. Patients and Methods ACPs enrolled onto phase I trials underwent neuropsychological assessment to evaluate cognitive functioning (CF) covering the following domains: memory (Hopkins Verbal Learning Test), executive functioning (Trail Making Test B), language (Boston Naming Test-Short Version and Controlled Oral Word Association Test), attention (Trail Making Test A and Wechsler Adult Intelligenence Scale-IV Digit Span), comprehension (Wechsler Adult Intelligence Scale-IV), and quality of life (Functional Assessment of Cancer Therapy–Cognitive Function). Structured interviews evaluated IC and decisional capacity. Psychological measures included distress (Hospital Anxiety Depression Scale) and depression (Beck Depression Inventory-II). Results One hundred eighteen ACPs on phase I trials were evaluated, with CF ranging from mild impairment to superior performance. Only 45% of ACPs recalled physician disclosure of the phase I trial purpose. The 50% of ACPs who correctly identified the phase I research purpose had greater CF compared with ACPs who did not, as revealed by the mean T scores for memory (37.2 ± 5.6 v 32.5 ± 5.1, respectively; P = .001), attention (29 ± 2.7 v 26.9 ± 2.4, respectively; P < .001), visual attention (35.2 ± 6.6 v 31.5 ± 6.2, respectively; P = .001), and executive function (38.9 ± 7.5 v 34 ± 7.1, respectively; P < .001). Older ACPs (≥ 60 years) were less likely to recall physician disclosure of phase I purpose than younger ACPs (30% v 70%, respectively; P = .02) and had measurable deficits in total memory (34.2 ± 5.0 v 37.3 ± 5.6, respectively; P = .002), attention (24.5 ± 2.6 v 28 ± 2.8, respectively; P < .001), and executive function (32.8 ± 7.3 v 36.4 ± 7.6, respectively; P = .01). Older ACPs, compared with younger ACPs, also had greater depression scores (10.6 ± 9.2 v 8.1 ± 5.2, respectively; P = .03) and lower quality-of-life scores (152 ± 29.6 v 167 ± 20, respectively; P = .03). After adjustment by age, no psychological or neuropsychological variable was further significantly associated with likelihood of purpose identification. Conclusion CF seems to play a role in ACP recall and comprehension of IC for early-phase clinical trials, especially among older ACPs.