Cancer risk among individuals of migrant origin in Belgium during the 2000s - Evidence of migration as a 'cancer risk transition'?

A population-based cohort study on changes in breast, lung and colorectal cancer incidence and mortality among non-Western immigrant women

BACKGROUND

Cancer risk varies geographically, and migrants are influenced by different risk factors before, during and after migration. Increased migration from non-Western countries to the Nordic countries calls for a better understanding of the migrants' cancer risk and the change in risk patterns over time. The aim of this study was to compare the incidence and mortality of breast, colorectal and lung cancer between non-Western immigrant and the native female population in Denmark, Finland, Iceland, and Norway.

MATERIAL AND METHODS

Data from national registries were processed and pre-analysed in each country. Multivariate Poisson regression models were used to model the relative differences in incidence and mortality as rate ratios (RR). The country-specific estimates and summary statistics were pooled together using a random effects model.

RESULTS

Non-Western immigrant women had significantly lower breast (RR 0.71, 0.65-0.78), colorectal (RR 0.72, 0.57-0.92) and lung (RR 0.55, 0.42-0.72) cancer incidence rates than native women, and the risk of these cancers among immigrant women increased with duration of residence. Differences were parallel in breast, colorectal and lung cancer mortality (RR 0.64, 0.55-0.74; RR 0.66, 0.48-0.92; RR 0.51, 0.34-0.79). Among immigrant women, higher education increased the risk for breast cancer and decreased it for lung cancer.

CONCLUSION

The results significantly complement and add to the previous findings of cancer burden and cancer burden transition among migrants and provide evidence of a prolonged cancer risk advantage among non-Western immigrant women. However, the findings show an increasing risk of lifestyle-related cancers with increasing duration of residence in the host country. Further studies are needed to discover underlying reasons for this phenomenon.

Colorectal cancer incidence and survival inequalities among labour immigrants in Belgium during 2004-2013

Colorectal cancer (CRC) is one of the leading causes of cancer-related morbidity and mortality. We aim to map out differences in CRC incidence and survival between first-generation traditional labour immigrants of Italian, Turkish and Moroccan descent and native Belgians; and assess the contribution of socioeconomic position (SEP) to these differences. Individually-linked data of the 2001 Belgian Census, the Crossroads Bank for Social Security and the Belgian Cancer Registry are used. Age-standardized incidence rates and incidence rate ratios are calculated by country of origin, with and without adjusting for SEP. For CRC patients, 5-year relative survival rates and the relative excess risk for dying within five years after diagnosis are calculated by migrant origin. Lower CRC incidence was observed among immigrants compared to native Belgians, in particular among non-Western immigrants, which could not be explained by SEP. Survival inequalities were less clear, yet, after adjusting for age and stage at diagnosis and educational attainment, we observed a survival advantage among Turkish and Italian immigrant men. Health gains can be made for the native population by adapting lifestyle. The later stage at diagnosis for immigrants is of concern. Barriers regarding screening as perceived by the vulnerable groups should be identified.

Cancer among Immigrants: Diverse Histories, Diverse Disparities, Diverse Opportunities to Promote Equity

Immigrants-people who live in a country different from their country of birth-constitute approximately 250 million people globally. Migrants are diverse in their reasons for immigration, ranging from those who are forced to flee their home country for survival, to those seeking a better life. Migrants face diverse barriers in access to care. Therefore, it is critical in the context of cancer health to improve our understanding of the epidemiology of cancer amongst migrants to inform policy, screening, and management. In this issue of Cancer Epidemiology, Biomarkers & Prevention, Yu and colleagues evaluate patterns in the incidence of infection-associated cancers-cancers of the stomach, liver, and cervix-amongst migrants in Australia. They demonstrate that the incidence of infection-related cancers is heterogeneous amongst immigrant populations, underscoring the value of studies that disaggregate groups in ways that reflect the diversity amongst these groups. In this editorial, we contextualize the work of Yu and colleagues in the setting of studies exploring cancer health amongst migrants in various parts of the world. We call attention to disparities in risk factors, prevention, screening, and access to care. Finally, we call on the research and medical communities to work to elucidate their diverse stories, understand their diverse disparities, and act upon diverse opportunities to promote equity. See related article by Yu et al., p. 1394.

Cancer Incidence in Migrants in Australia: Patterns of Three Infection-Related Cancers

BACKGROUND

Australia provides an ideal population-base for cancer migration studies because of its multicultural society and high-quality cancer registrations. Among migrant groups there is considerable variability in the incidence of infection-related cancers; thus, the patterns of three such cancers were examined among migrant groups relative to Australian-born residents.

METHODS

Using national incidence data for cancers of the stomach, liver, and cervix diagnosed during 2005 to 2014, incidence rates were compared for selected migrant groups with the Australian-born population using incidence rate ratios (IRR), from a negative binomial regression model.

RESULTS

Wide variations in incidence between countries/regions of birth were observed for all three cancers (P < 0.0001). The patterns were similar for cancers of the stomach and liver, in that migrants from countries/regions with higher incidence rates maintained an increased risk in Australia, with the highest being among South American migrants (IRR = 2.35) for stomach cancer and among Vietnamese migrants (5.44) for liver cancer. In contrast, incidence rates of cervical cancer were lower for many migrant groups, with women from Southern Asia (0.39) and North Africa (0.42) having the lowest rates. The rate of cervical cancer was higher in migrants from New Zealand, Philippines, and Polynesia.

CONCLUSIONS

Several Australian migrant groups were found to experience a disproportionate burden of infection-related cancers; further studies of associated risk factors may inform the design of effective interventions to mediate these disparities.

IMPACT

By identifying these migrant groups, it is hoped that these results will motivate and inform prevention or early detection activities for these migrant groups. See related commentary Dee and Gomez, p. 1251.

Health inequalities among Russian-born immigrant women in Finland: longitudinal analysis on cervical cancer incidence and participation to screening

Research has documented both lower and higher cancer incidence among migrants. Evidence among the large Russian-born migrant population, however, is scarce. We examined cervical cancer incidence and screening participation among Russian-born immigrant women in Finland, a country with complete cancer registration and universal public health care including organized cancer screening. Our study population included all the women that resided in Finland during 1970–2017 and was formed linking individual-level data from four nationwide registries. The linked data sets on cancer and cancer screening were analysed separately using different statistical models. Russian-born immigrant women had increased (+62%) incidence of cervical cancer compared to the general Finnish female population, and they participated in cervical cancer screening slightly less than other women. Our findings showed no consistent transition pattern in cancer incidence or screening participation rate with duration of stay. Potential explanations for the observed differences include institutional and behavioural factors. Cervical cancer is one of the most preventable cancers, and cancer screening can both prevent and reduce incidence and mortality of cervical cancer. Efforts should be made to encourage migrant populations to participate in cervical screening.

Effect of Human Development Index and other socioeconomic factors on mortality-to-incidence ratio of lips and oral cavity cancer in Mexican states: an ecological study

OBJECTIVES

To assess the association between the Human Development Index (HDI) and covariates on the mortality-to-incidence ratio (MIR) of lips and oral cavity cancer (LOCC) in Mexico.

DESIGN

Ecological study.

SETTING

Data from 32 Mexican states for year 2019.

PARTICIPANTS

Data set of male and female populations from Mexico.

EXPOSURES

Socioeconomic conditions based on HDI and covariates related to healthcare system capacity (total health spending per capita, school dropout and ratio of medical personnel in direct contact with patients).

PRIMARY AND SECONDARY OUTCOME MEASURES

MIR of LOCC by state and sex was calculated from the Global Burden of Disease Study website for year 2019. Data for calculating HDI 2019 by state and covariates were obtained from the National Institute of Statistics and Geography. A multiple regression model was constructed to measure the effects of HDI and covariates on LOCC-MIR.

RESULTS

Among the states with the highest HDI (>0.780), Colima had the highest aged-standardised rates per 100.000 in men for incidence (5.026) and mortality (3.118). The greatest burden of the disease was found on men, with the highest Men:Women MIR in Colima (3.10) and Baja California Sur (2.73). The highest MIR (>0.65) was found among the states with the lowest HDI (Oaxaca and Chiapas). For each unit of increase of the HDI there was a decrease in the LOCC- MIR of -0.778, controlling for the covariates. The most suitable regression model explained the 57% (F (p): 0.000) of the variance.

CONCLUSIONS

Men were most affected by LOCC in Mexican states. The highest MIRs of LOCC were found in the states with the highest HDI. But a worse prognosis of the disease, expressed as a higher MIR, is expected in contexts with lower HDI in the country, even with lower MIRs.