Cancer incidence and mortality are not equally distributed across countries and individuals. The magnitude and profile of cancer evolve continuously over time, in parallel with the global socioeconomic development of societies. Transitions towards better economic and living conditions have brought many benefits but have also led to increasing exposure to various risk factors for cancer.

Within each population, the socioeconomic position of individuals is a key factor explaining the cancer patterns and trends; the most disadvantaged individuals are disproportionately harder hit. However, social inequalities in cancer vary substantially between countries, which indicates the potential for prevention.

The roles of the context and of inefficiencies in the provision of health-care services are crucial. Whereas disadvantaged individuals, who are most in need, often cannot fully benefit from health-care services, affluent citizens may receive too much medical care, which can be unnecessary or even harmful. This causes a waste of resources and precludes the reduction of the cancer burden and the sustainability of the health systems.

These issues are described in Reducing Social Inequalities in Cancer: Evidence and Priorities for Research (IARC Scientific Publication No. 168), and understanding them is essential to inform local and supranational planning for cancer control interventions.

The work is conducted within the IARC Cancer Inequalities Team, and it is structured across three main programmatic areas: (1) Global development, (2) Social inequalities, and (3) Health-care inefficiencies.