Disparities in overall and site-specific cancer mortality among immigrant generations in Sweden: A nationwide follow-up study over three decades

We examined the overall and site-specific cancer mortality disparities among first-generation - separately in adults (G1) and children (G1.5) at immigration - and second-generation (G2) immigrants and their countries of origin using population-based registries in Sweden, encompassing over 8.5 million individuals aged 20 and above residing in Sweden since 1990, with follow-up until December 31, 2023. Cox proportional hazard models were fitted, stratified by gender, to estimate hazard ratios and 95% confidence intervals compared to natives. Mortality rates for most cancers transitioned from lower in G1 towards the rate of natives in G2. However, elevated mortality rates were sustained across generations for liver cancer in males and stomach cancer in females. Among G2, mortality from lymphohematopoietic cancers in males, and lung and cervix uteri cancers in females were elevated - by 10%, 9%, and 17% respectively compared to natives. Country of origin analyses revealed substantial disparities. For instance, G2 females with Nordic parental origin had a 13% higher risk of death from lung cancer, while those with non-Western parental origin had a 54% lower risk as compared to natives. These findings suggest a generational and arrival-age dynamics of cancer mortality and highlight target groups for cancer prevention and control among immigrants.