A study of informed consent (IC), age, and cognitive function (CF) among advanced cancer patients (acp) in phase I trials

Abstract

6548 Background: Ethical concerns exist about acps’ ability to provide adequate informed consent (IC) for phase I trials. While cognitive impairment (CI) among acp is well-recognized due to multiple factors, e.g., previous effects of chemotherapy, age, psychological status, the prevalence of CI among acp in phase I trials has never been described. Methods: Acp CF was assessed using a neuropsychological battery of instruments: Hopkins Verbal Learning (HVLT); Verbal Fluency; Mini-Cognitive Assessment; Trail-making (Parts A& B); Boston Naming (short); WAIS subtests (Comprehension and Digit Span). Acp underwent semi-structured interviews to evaluate elements of IC, and completed the FACT-COG and the Hospital Anxiety and Depression Scale (HADS). Results: To date, a total of 34 acp enrolling in Phase I trials have been studied. Median age: 63y (range: 38–81y); 77% male; 77% Caucasian; 67% > HS education. Regarding IC understanding: Only 20% of responding acp correctly identified the purpose of Phase I trials; all subjects could recall risks of side effects, correctly stated they could refuse trial participation, and stated they could withdraw at anytime; 53% believed the trial was their only option. Older acp (>age 55y) were less likely to correctly describe the research purpose of the trial (29% v. 71% p=0.02). Older acp had measurable deficits in CF: Boston Naming (14±0.9 v.15±0.3, p=0.09); HVLT Total Recall (14±2 v.26±6, p<0.00) and Discrimination Index (7.5±3 v.11±1, p=0.03); Digit Span-Backwards (4±2 v.7±2, p<0.00); Trail-making B (244±64 v.188±51, p=0.04). While there were no differences in perceived CI (95±18 v.101±19, p=0.5) or impact on quality of life (25±7 v. 27±5, p=0.5), both groups had scores well below prior reported means. Older acp tended to report depressive symptoms more than younger acp (8±2 v.6±1, p=0.07). Conclusions: Our data suggest that CF may play a role in acp understanding of IC for clinical trials, especially among the elderly. Further research is needed, given ethical concerns regarding elderly acp in clinical trials of experimental agents who may have CI. No significant financial relationships to disclose.