Cognitive Functioning Affects the Ability of Patients With Advanced Cancer to Give Informed Consent
Approximately half of patients with advanced cancer who are enrolled in phase 1 clinical trials do not know the ultimate goal of the study.
In patients with advanced cancer, cognitive functioning may play a role in their ability to recall and understand informed consent for participation in phase 1 clinical trials, according to the results of a study published in The Journal of Clinical Oncology.1
In the study, only a minority of patients (45%) recalled the physician disclosing dosage or toxicity as the primary phase 1 research purpose, and only half of patients were able to identify the research purpose of the experimental study.
“Clinicians must gain awareness and recognize that cancer-related cognitive impairments may adversely impact the advanced cancer patient's decisional capacity and understanding of the nature of informed consent for phase 1 trials,” study researcher Fay Hlubocky, PhD, of the University of Chicago in Illinois, told Cancer Therapy Advisor. “Routine assessment of cognitive symptoms during the informed consent process should be practiced and standardized for all patients considering trial participation in order to identify potential deficits and address these symptoms by targeting treatment.”
According to Dr Hlubocky, prior research has consistently shown that patients with advanced cancer maintain an imperfect understanding of the nature of informed consent for phase 1 clinical trial participation.
“Despite a rigorous informed consent process involving physician disclosure of the phase 1 purpose as determining drug safety, and with this explanation further emphasized and highlighted within the consent form, only a minority of these patients report an adequate understanding of this purpose as safety or dosage,” she explained. “This inability to correctly state the phase 1 purpose is due in part to multiple factors, including the patient's underlying hope and motivation for therapeutic benefit, as well as oncologist communication.”
Dr Hlubocky and colleagues wanted to investigate the role of cognitive function and its effect on patient comprehension of informed consent. They looked at 118 patients with advanced cancer enrolled in phase 1 trials that were being conducted by the University of Chicago's developmental therapeutics clinic. Patients underwent neuropsychological assessment to evaluate cognitive functioning. Testing included evaluation of several domains including memory, executive functioning, language, attention, comprehension, and quality of life. Cognitive function ranged from mild impairment to superior performance.
“Our finding is consistent with previous research indicating only 25% to 43% of patients could correctly recall and state the phase 1 purpose after the consent discussion,” Dr Hlubocky said. “However, for our study, these same patients who correctly recalled this purpose had enhanced cognitive function for memory and attention [compared with] those [who were] unable to recall the purpose. Although [it is] not a formal decisional capacity domain, recall is an essential cognitive task that is unique to memory and [is] also representative within all domains; it declines with increasing age and thus, [is] important to evaluate.”