This paper makes the case for not just studying the consequences of overdiagnosis, but also following the consequences of talking about overdiagnosis. Instead of understanding scientific research as describing reality, it adopts a constructivist approach, understanding knowledge as constructed through networks of people and things. Research findings do not just describe a world ‘out there’; they bring new worlds into being. In other words, new research not only informs us, it transforms us.

Based on autoethnographic insights, the paper explores my experiences of being transformed from a ‘cancer patient’ to an ‘overdiagnosed person’ through my PhD fieldwork. As a result of my research, my diagnosis of ‘melanoma in situ’ was transformed from a timely and potentially lifesaving intervention into almost certainly an unnecessary overdiagnosis. Newly holding a different understanding of my diagnosis to other members of the melanoma support groups, I had to learn to live with this new identity outside of the communities I once belonged to and relied on. Rooted in this experience, this paper argues that academics must consider the consequences of their research for people who might come to understand their diagnoses, health and identities in new ways as a result of the knowledge they disseminate. This work examines what support we might need to provide to those who have come to understand themselves in new ways through exposure to research on overdiagnosis.

More broadly, the paper considers how the dissemination of research on overdiagnosis affects people’s trust in biomedicine. In presenting their work as descriptions of reality, biomedical practitioners promote themselves as having access to ‘the truth’ via the scientific method. When cancer patients are transformed into potentially overdiagnosed people, their ‘truth’ or ‘reality’ fundamentally changes. For many of these people, trust in biomedicine is broken in this process. The paper explores how we might talk about overdiagnosis in a way that does not damage people’s trust. The problem may not be with patients’ ability to cope with or understand uncertainty; rather, the issue lies with researchers’ ability to present the contested and dynamic nature of knowledge. Instead of reinforcing the idea that biomedicine has access to truth and certainty, researchers working on overdiagnosis must be humble and admit that biomedical knowledge production is the process of constructing facts amidst huge uncertainty. We consider if trust can be formed on basis of a nuanced and constructivist understanding of biomedicine, rather than the assertion of truth.

In following the effects of scholarship beyond conferences and journals and into bodies, communities and homes, this paper highlights that doing research does things. Learning information about overdiagnosis can leave people who were once ‘cancer patients’ isolated from support and lacking trust in biomedicine. The effects of knowledge dissemination must be considered as part of our duty as researchers to ‘do no harm’.

Objectives The paper aims to highlight some of the consequences of raising awareness of research on overdiagnosis, particularly for existing ‘cancer patients’.

Method The paper is based on ethnographic fieldwork carried out at POD 2022, followed by interviews with 15 scholars I met at the conference. These insights into researchers’ experiences are combined with autoethnographic reflections on the entangled relationship between my research on overdiagnosis and my identity as a ‘cancer patient’.

Results This research suggests that we must consider the provision of care available for people who come to understand themselves as ‘potentially overdiagnosed people’ as the result of our research, having once been ‘cancer patients’.

Conclusions The paper argues that there is a need to change the grounds upon which medicine asserts its authority and forms trust with patients and publics. It suggests that instead of building ‘patient’ and ‘public’ trust in biomedical research and practice on the basis of assertions of certainty and access to ‘truth’, we must find ways to build trust while also admitting the uncertainty and dynamism involved in the construction of knowledge. If we fail to do so, communicating the possibility of overdiagnosis can have the consequence of radically and irreparably damaging people’s trust in the biomedical enterprise. Instead of just doing research, we must consider what research does, following the beneficial and harmful consequences of the knowledge we produce in the world.