Cancer inequalities in the United Kingdom and the data used to measure them: a scoping review.

Significant cancer inequalities may exist across the United Kingdom (UK). Data are required to delineate and quantify these inequalities. This scoping review was undertaken to map the research evidence on UK cancer inequalities and determine the current data available, and the data gaps, that, if filled, could inform a strategy to reduce them. 444 studies were included. Their distribution across inequality domains, care pathways and cancer sites was uneven. The majority of studies were based on administrative datasets, notably cancer registry data, with a wide-range of methods used to define inequality groups. No UK-wide population-based evidence was identified. The landscape of data available in the UK to study cancer inequalities is uneven. Although there is a large volume of evidence available, there remain major gaps in both the data available and the knowledge base they are deployed to generate. This deficit needs to be addressed as a matter of urgency.