Increasing participation of underrepresented groups in cancer early detection research: a scoping review.

Background: Improvements in access to early-detection research on cancer are still urgently needed to ensure that new research on early-stage cancer detection benefits all groups in society. To achieve this, cancer early detection (ED) studies must include participants from all walks of life. There are unique aspects to cancer early detection research that may deter potential research participants and complicate efforts to involve people from underrepresented backgrounds that require a review on its own merit. For instance, a unique risk for cancer ED research is overdiagnosis and overtreatment, in which a tumour is uncovered and treated that would not have led to the patient's death if left undiscovered and untreated. This potential 'side effect' of cancer ED research participation is particularly problematic for those without adequate access to healthcare and insurance. Methods: Contributing to a growing literature on approaches to increase diversity in cancer detection research, we conducted a targeted scoping review to identify published approaches that have been implemented and tested, either quantitatively or qualitatively, to improve participation of minoritised groups in cancer ED research. Results: This review identifies themes in the 38 included studies that aimed to recruit and involve participants from underserved groups in cancer ED research so that future studies may learn from or further test these varied strategies. We narratively group the review in terms of the barriers identified, and the approaches that have been designed to improve participation. These include rethinking recruitment locations and partnerships with local communities, designing educational interventions, combining research with community needs, increasing cultural competence of research teams, and overcoming practical barriers in study design. Conclusions: This scoping literature review highlights various tools, empirically tested, that research teams can employ to improve participation rates of groups underrepresented in cancer ED research. Combinations of these methods can help overcome the perceived barriers to participation in cancer research that mainly affect people without a cancer diagnosis from these minoritised groups. Not only will these methods increase the generalizability and representativeness of studies; the highlighted approaches also contribute to a more significant shift in research culture towards less extractive and more trusting relationships between researchers and the public.