Despite the assumed importance of migrant group concentration in an area, our understanding of how this is related to health is limited. On the one hand, a higher ‘ethnic density’ is associated with better mental health outcomes among minorities. This has been attributed to social cohesion effects: a larger presence of same-origin peers leads to more social cohesion, a sense of community and belonging, which may have buffering effects against the consequences of stressors such as discrimination and racial harassment. On the other hand, a higher ethnic density may facilitate local political mobilisation, which could stimulate the local population to obtain better community services. The level of social cohesion may also provide social support relevant for physical health, by sharing information regarding health care, transport to facilities, and encouraging healthy behaviour. Ethnic density effects are harder to observe for physical morbidity and cause-specific mortality, however.

This paper’s main question is how own-group presence affects cancer mortality in Belgium. Among Belgians, large origin groups and for major cancer sites, we explore the association between the percentage of individuals of that origin group in a municipality, and mortality for ages 40 to 69. We control for a range of individual covariates and municipal-level deprivation. We furthermore examine whether individual resources and migrant generation alter the relationship between cancer mortality and own-group presence. Our data come from the linked Belgian 2001-2011 census and are analysed using multilevel Poisson regression.

Results point to protective own-group effects for some sites among Belgians and Europeans, whereas the opposite is true for non-Western non-Europeans. Finding also indicate a vulnerable position for second-generation migrants where the presence of their origin group is high.

Our results may point to better quality and delivery of services that affect cancer mortality for Belgians and first-generation Europeans where their presence is higher.