Heterogeneous and dynamic lung cancer mortality among immigrants relative to native-born populations in France, 2000-2021.

Immigrants tend to have lower lung cancer mortality compared to natives, with some exceptions by region of birth. To date, findings on cancer mortality among immigrants in Europe show that cancer mortality trends vary by host country, region of birth, sex, and cancer type. We aim to describe immigrant lung cancer mortality relative to natives and disparities by region of birth, clarify the role of social factors, and assess temporal trends. We used data from France's national mortality registry and population censuses to evaluate immigrant and native lung cancer mortality rates for the 2000-2021 period. We estimated sex-specific mortality rate ratios (MRRs) to assess relative lung cancer mortality by region of birth. Interaction was tested and analyses were further stratified by social deprivation and subperiod. Within-region of birth social gradients in lung cancer mortality were assessed. Foreign-born women (MRR: 0.82; 95% CI: 0.75-0.90) and men (MRR: 0.93; 95% CI: 0.88-1.00) had lower lung cancer mortality relative to natives, with some exceptions by region of birth. Interaction and stratified analysis results show that region of birth trends differed across social deprivation groups. Results for within-group social gradients show a divergence between men and women. Differences between immigrants and natives tended to widen over time. Our study adds to our understanding of the complex mechanisms underlying lung cancer mortality among immigrants, and how they diverge from native-born population patterns. These findings highlight questions about how sex, region of birth, and social deprivation intersect in lung cancer mortality.