Prostate cancer incidence and mortality among immigrants in Finland between 2000 and 2017 - a register-based cohort study.

Background and purpose: Prostate cancer impacts millions of men worldwide each year, and its significance will continue to rise as populations age. Literature demonstrates differences in cancer burden between immigrant groups and non-immigrants across the world. Despite its prevalence, little research has focused primarily on prostate cancer among immigrants.

Patients/material and methods: We utilized individual-level data on all immigrant men who had lived in Finland for over a year between 1973 and 2017 and aggregate data on Finnish-born men to determine immigrants' incidence of and mortality from prostate cancer in relation to the men born in Finland. This gave us a study population of 162,844 non-Western and 56,127 Western immigrant men. Cases and deaths from the study period (2000-2017) were analyzed with the multivariate Poisson regression model for the groups, non-Western and Western immigrants separately.

Results and interpretation: Non-Western men had a relative risk (RR) of 0.663 (95% confidence interval [CI] 0.609-0.722) for cases and 0.803 (0.646-0.997) for deaths. Western men had RRs of 0.876 (0.784-0.978) and 0.78 (0.567-1.072), respectively. A longer duration of residence and a younger age at immigration increased the risk for prostate cancer. Compared to the men born in Finland, both immigrant groups showed a lower risk of prostate cancer. Non-Western men may have also had a lower risk of death from it. Prostate cancer mortality in non-Western immigrants appears to be high compared to its incidence. While uncertain, this implication is concerning enough to warrant further research into the topic.