Excessive Optimism Plagues Early Cancer Studies

New data suggest that unrealistic optimism is common in patients who participate in early-phase cancer clinical trials and may interfere with their ability to provide informed consent.

Lynn A. Jansen, PhD, with Oregon Health Sciences University in Portland, and colleagues reviewed responses to questionnaires completed by 72 patients enrolled in phase I, phase I/II, or phase II clinical cancer trials at a major comprehensive cancer center during a recent 14-month period.

Forty-one patients had blood cancer, 29 had myelodysplastic syndrome, 1 had breast cancer, and 1 had lung cancer.

The term “unrealistic optimism,” which is also called “optimism bias,” refers to optimism that results from a bias in which a person believes that he/she is more likely to experience positive outcomes or less likely to experience negative outcomes than other patients in the same situation. Jansen and associates caution that unrealistic optimism may undercut the informed consent process by making it difficult for a patient to “apply information realistically.”

For their study, the investigators used the comparative risk/ benefit assessment questionnaire that aimed to assess how well participants understood the trial’s objective. Participants demonstrated unrealistic optimism in response to 3 of 5 questions about the likelihood of particular cancerrelated events happening to them compared with other trial participants. Overall, 59.7% were unrealistically optimistic when they were asked whether their cancer was likely to be controlled by the experimental drug being evaluated in the trial, 62.5% were unrealistically optimistic when asked whether they would experience a health benefit from the drug used in the trial, and 38.9% were unrealistically optimistic when asked whether they would experience a health problem from the drug tested in the trial.

Trial participants were also asked an open-ended question to gauge their understanding of the purpose of the trial. Results of the so-called “Purpose Question” showed that 72.9% of respondents correctly understood that the purpose of the trial in which they were enrolled was to advance generalizable knowledge with the potential to benefit future patients, and not necessarily to benefit them.

No significant association was found between responses to the Purpose Question and the unrealistic optimism scores.

Jansen and colleagues noted that their results are preliminary and emphasized that their study was conducted at a single institution, and that the distribution of malignancies was “skewed away” from solid tumors. They also say that they have not yet looked at patients who decline to participate in early-phase clinical trials, and thus do not know whether this group also demonstrates unrealistic optimism regarding cancer-related events.

"Improving the consent process in oncology research will require us to do more than address deficits in understanding," the investigators pointed out. "It will require us to pay more attention to how patients apply information to themselves and to become more aware of the social-psychological factors that might impair decision-making in this context.”

Contrary to popular opinion, “hope and optimism in the research context” are not necessarily “ethically benign,” noted Jansen and colleagues.