Survival and informed consent understanding of elderly advanced cancer patients enrolling in phase I trials

Abstract

8109 Background: Demographic characteristics of geriatric advanced cancer patients in early phase trials have not been described, and little is specifically known about their understanding of the informed consent process for such trials. Methods: Subset analysis of an existing database of results from surveys and semi-structured face-to-face interviews of advanced cancer patients in Phase I trials regarding their informed consent and decisions to enroll in a clinical trial. Survival data was also collected. Results: Of 212 Phase I trial subjects, 36% were age 65 or older. The median age of this subgroup was 71 (range 65–82). Race distribution was comparable between the two age groups. Regarding informed consent understanding of the research purpose of a Phase I trial, younger patients were more likely to identify toxicity as the outcome measurement (80% vs 20%, p=0.06). Older Phase I subjects were more likely to answer “I don’t know” regarding trial purpose. Older Phase I subjects also reported not being given alternative care options, including palliative care (40% vs 11%, p=0.03). Older Phase I subjects reported being less worried about dying (28% vs 13%, p=0.01). There were significant differences in survival after enrollment. Median survival of older patients was 10.8 months (range 0.9 to 48.7 months), compared to younger patients at 6.4 months (range 0.2 to 35.9 months) (p=0.005). Conclusions: Older subjects in Phase I trials, while sharing many demographic characteristics with younger patients, survived significantly longer than younger subjects. Older subjects had poorer understanding of the trial purpose, and reported being offered fewer alternative treatment options. The survival advantage of the elderly patients in this highly selected population is an interesting and unexpected finding and suggests a significant selection bias of elderly advanced cancer patients entering early phase trials. This probable selection bias, and elderly subjects’ poor clinical trial consent understanding, deserve further study. Author Disclosure Employment or Leadership Consultant or Advisory Role Stock Ownership Honoraria Research Funding Expert Testimony Other Remuneration Vitas Hospice