Background: Patient and public involvement (PPI) in cancer research promotes more democratic research and fosters trust between science and society. By engaging people from the civil society with lived experience of cancer as partners rather than subjects, PPI enhances the relevance and impact of scientific findings; it acknowledges the value of experiential knowledge and allows citizens to help define research priorities. PPI in research often unfolds with a small group of individuals and through in-person workshops or committees, focusing on participants’ experience of an illness.
 
Objectives: Research Engine, developed by Seintinelles, a collaborative platform that facilitates the engagement of the civil society in cancer research, is an innovative digital PPI tool that broadens participative engagement in research. It enables citizens to share their questions with researchers and views about cancer research. The platform pursues two complementary aims: generating dialogue and priority-setting research. On the one hand, it aims at fostering conversation between citizens and researchers, ensuring that scientific advances and challenges are communicated clearly, and working at bridging the gap between the public and research. On the other hand, it enables cancer research priority setting, with the aim to inform and inspire future research proposals and funding calls with the questions and priorities identified by the public community.
 
Method: The French public could participate through a short online survey or workshops. Participants were recruited through Seintinelles and patient organisations.
 
Results: In 2024, 1073 participants shared 2 299 questions through an online survey and 5 workshops. The questions were analyzed thematically and through a clustering analysis, leading to the identification of 10 themes. The first theme, “Quality of life during and after cancer,” represented 25% of all questions. “Cancer risk factors” accounted for 20%, making it the second largest theme, followed by “Treatments.” The fourth and fifth themes concerned “Organization and access to cancer care” and “Research.” The remaining four themes, each representing less than 10% of questions, addressed “Screening,” “Key figures on cancer,” “Cancer recurrence,” and “Biology of cancer.” Participants with an experience of cancer were more likely to ask about Quality of life, Cancer care, and Cancer recurrence, but less likely to share questions about Screening, and Key statistics. Being a carer increased the likelihood of questions on quality of life and decreased questions on screening. Older participants were less likely to ask about Cancer risk factors and Research.
 
Conclusion: While participants perceive research as treatment-centered, their main concerns relate to quality of life and risk factors. Many of the questions were information requests about existing results. There is a need to better understand how research on cancer works. Difficulty of sharing questions, with only 66% of the participants asking questions. The results suggest a need for more and better support for the public in large-scale participatory research processes.