A cross-national perspective of migration and cancer: incidence of five major cancer types among resettlers from the former Soviet Union in Germany and ethnic Germans in Russia.

BACKGROUND: Few studies compared cancer incidence among migrants both to their host countries and to their population of origin. We aimed to compare cancer incidence of ethnic Germans who migrated from the former Soviet Union to Germany (resettlers) to those living in Russia as well as to the German and the Russian general populations. METHODS: The cancer registry of North Rhine-Westphalia identified incident cases of stomach, colorectal, lung, breast and prostate cancer in resettlers and the general population of the administrative district of Münster (Germany) between 2004 and 2013. The Tomsk cancer registry collected the same data in ethnic Germans and the general population of the Tomsk region (Russia). We used standardised incidence rate ratios (SIRs) to compare rates of resettlers and ethnic Germans with the respective general populations. RESULTS: The total number of person-years under risk was 83,289 for ethnic Germans, 8,006,775 for the population of Tomsk, 219,604 for resettlers, and 20,516,782 for the population of Münster. Incidence of the five investigated cancer types among ethnic Germans did not differ from incidence of the general population of Tomsk. Compared to the general population of Tomsk, incidence among resettlers was higher for colorectal cancer in both sexes (females: SIR 1.45 [95% CI 1.14-1.83], males: SIR 1.56 [95% CI 1.23-1.97]), breast cancer in females (SIR 1.65 [95% CI 1.40-1.95]), and prostate cancer (SIR 1.64 [95% CI 1.34-2.01]). Incidence rates of these cancer types among resettlers were more similar to rates of the general population of Münster. Incidence of stomach and lung cancer did not differ between resettlers and the general population of Tomsk. CONCLUSIONS: After an average stay of 15 years, we observed that incidence of colorectal, breast and prostate cancer among resettlers converged to levels of the general population of Münster. Resettler's incidence of stomach and lung cancer, however, was comparable to incidence in their population of origin. Causes must be investigated in subsequent analytical studies.

Comparison of female breast cancer between Russia and Germany: A population-based study on time trends and stage at diagnosis.

OBJECTIVES: While a mammography-screening program (MSP) is being offered systematically in Germany since 2009, the dispanserizatsiya has been implemented in Russia since 2013. This study examined trends of stage at breast cancer diagnosis in two Russian regions and compared the results with the development in Germany. In addition, we aimed to gain further insights into the early detection of breast cancer in Russia. METHODS: Incidence data from two cancer registries in Russia and 12 population-based cancer registries in Germany were used to analyse breast cancer incidence rates among women above age 30 over time. Further, we calculated rate ratios to compare the age group-specific incidence rates after the implementation of MSP in Germany (2010-2014) with the period before implementation (2003-2005) separately for each tumour stage and all stages combined. RESULTS: During the study period from 2003 to 2014, age-standardised rates for breast cancer were 54.6 and 116.7 per 100,000 for Russia and Germany, respectively. The proportion of the T1 stage at diagnosis among Russian women aged 50 + is half than that in Germany. Nevertheless, we observed an increasing trend of early-stage alongside the reduction of advanced-stage incidence rates of breast cancer in Russia. CONCLUSIONS: The observed trend in Russia may reflect overall positive changes in early detection of breast cancer, with actual proportion of T1 stage still far behind Germany. Advances in breast cancer screening efforts through the dispanserizatsiya may help to further reduce the breast cancer burden.