Liver and gallbladder cancer in immigrants to Sweden

Cervical, liver and stomach cancer incidence and mortality in non-Western immigrant women: a retrospective cohort study from four Nordic countries

BACKGROUND

Cervical, liver and stomach cancers are the most common infection-associated malignancies and the leading cause of morbidity in non-Western regions. We compared the incidence and mortality of these cancers between non-Western immigrant and non-immigrant Nordic female populations. We also analysed the effect of age at immigration, duration of residence and education on cancer burden.

MATERIAL AND METHODS

Study population consisted of women residents in Denmark, Finland, Iceland and Norway in 1973-2020. Non-Western women contributed 3.1% of the total 260 million person-years at risk. All women were followed from their 20th birthday, or from the date of immigration if after, until the date of their first primary cancer diagnosis, death, emigration, or the end of the country-specific study period. All data were adjusted for 10-year age groups and calendar periods, and immigrant data was further broken down by region of birth, age at immigration and education level. Country-specific estimates were produced by multivariable Poisson regression and pooled in Finland with a random effects model.

RESULTS

Altogether, there were 60 982 cases of cervical, liver and stomach cancer in the study population, causing 36 582 deaths. The immigrant women had significantly higher liver (rate ratio [RR] 1.78, 95% confidence interval (CI) 1.03-3.06) and stomach cancer incidence (RR 1.68, CI 1.29-2.18), and stomach cancer mortality (RR 1.49, CI 1.17-1.92) than non-immigrant women. In the immigrant population, high education was related to lower incidence and mortality of studied cancers. The rate ratio of cervical cancer decreased with duration of residence and increased with rising age at immigration.

CONCLUSION

Due to the increased incidence and mortality of infection-related cancers and changes in cancer patterns by age at immigration and duration of residence, attention should be paid to targeted health care services for immigrants. Special efforts should be given to women who have spent their youth in high-risk areas.

Targeting population groups with heavier burden of hepatocellular carcinoma incidence: a nationwide descriptive epidemiological study in Sweden

Contemporary European studies examining associations between socioeconomic status and hepatocellular carcinoma (HCC) incidence are scarce. We aimed to target population groups with a heavier burden of HCC by assessing associations of individual‐level sociodemographic variables and neighbourhood deprivation with all‐stage and stage‐specific HCC incidence rates (IR). Patient and population data stratified by calendar year (2012‐2018), sex, age (5‐year groups), household income (low, medium and high), country of birth (Nordic, non‐Nordic) and neighbourhood deprivation (national quintiles Q1‐Q5) were retrieved from Swedish registers. HCC stages were defined by Barcelona Clinic Liver Cancer stages 0 to A (early‐stage) and B to D (late‐stage). IR (per 100 000 person‐years) were estimated by Poisson regression models. Men had four times higher IR than women. IRs increased markedly with lower household income as well as with neighbourhood deprivation. Seven times higher IR was observed among people with a low household income living in the most deprived neighbourhoods (IR 3.90, 95% confidence interval [CI] 3.28‐4.64) compared to people with a high household income living in the least deprived neighbourhoods (IR 0.58, 95% CI 0.46‐0.74). The gradient across income categories was more pronounced for late‐stage than early‐stage HCC. IR reached 30 (per 100 000 person‐years) for people in the age span 60 to 79 years with low income and 20 for 60 to 79 year old people living in the most deprived neighbourhoods (regardless of income). Men with low household income and/or living in the most deprived neighbourhoods might be considered as primary targets in studies evaluating the cost‐effectiveness of screening for early‐stage HCC detection.

Subtypes of Native American ancestry and leading causes of death: Mapuche ancestry-specific associations with gallbladder cancer risk in Chile

Latin Americans are highly heterogeneous regarding the type of Native American ancestry. Consideration of specific associations with common diseases may lead to substantial advances in unraveling of disease etiology and disease prevention.

Here we investigate possible associations between the type of Native American ancestry and leading causes of death. After an aggregate-data study based on genome-wide genotype data from 1805 admixed Chileans and 639,789 deaths, we validate an identified association with gallbladder cancer relying on individual data from 64 gallbladder cancer patients, with and without a family history, and 170 healthy controls. Native American proportions were markedly underestimated when the two main types of Native American ancestry in Chile, originated from the Mapuche and Aymara indigenous peoples, were combined together. Consideration of the type of Native American ancestry was crucial to identify disease associations. Native American ancestry showed no association with gallbladder cancer mortality (P = 0.26). By contrast, each 1% increase in the Mapuche proportion represented a 3.7% increased mortality risk by gallbladder cancer (95%CI 3.1–4.3%, P = 6×10⁻²⁷). Individual-data results and extensive sensitivity analyses confirmed the association between Mapuche ancestry and gallbladder cancer. Increasing Mapuche proportions were also associated with an increased mortality due to asthma and, interestingly, with a decreased mortality by diabetes. The mortality due to skin, bladder, larynx, bronchus and lung cancers increased with increasing Aymara proportions. Described methods should be considered in future studies on human population genetics and human health. Complementary individual-based studies are needed to apportion the genetic and non-genetic components of associations identified relying on aggregate-data.

A lot of attention has been paid to Latino heterogeneity related to individual proportions of Native American, European and African ancestry. The importance of the type of Native American ancestry for health, however, has hardly been studied. Here we examined genetic data from 2,039 admixed Chileans to investigate possible associations between top causes of death and the two major types of Native American ancestry in Chile. Our findings demonstrate the necessity of suitable surrogates for ancestry estimation which mirror the actual composition of the study population, and the advantage of considering fine-scale Latino heterogeneity for unraveling of disease etiology and personalized healthcare.

A review of the infection-associated cancers in North African countries

Cancer is typically classified as a leading non-communicable disease; however, infectious agents, such as Helicobacter pylori (H. pylori), hepatitis B virus (HBV), hepatitis C virus (HCV) and human papilloma virus (HPV), contribute significantly to the pathogenesis of various cancers. Less developed countries, including countries of the North African (NA) region, endure the highest burden of infection-related cancers. The five most common infection-associated cancers in NA in order of incidence are bladder cancer, cervical cancer, liver cancer, stomach cancer, and nasopharyngeal carcinoma. This review aims to outline the epidemiologic pattern of infection-associated cancers in five NA countries (namely: Morocco, Algeria, Tunisia, Libya and Egypt) highlighting the similarities and differences across the region. The present study employed an initial literature review of peer-reviewed articles selected from PubMed, ScienceDirect and World Health Organization (WHO) databases based on key word searches without restriction on publication dates. Original research articles and reports written in French, as well as data from institutional reports and regional meeting abstracts were also included in this extensive review. Egypt, Libya, Tunisia, Algeria and Morocco were selected to be the focus of this review.

Gallbladder carcinoma: Prognostic factors and therapeutic options

The outcome of gallbladder carcinoma is poor, and the overall 5-year survival rate is less than 5%. In early-stage disease, a 5-year survival rate up to 75% can be achieved if stage-adjusted therapy is performed. There is wide geographic variability in the frequency of gallbladder carcinoma, which can only be explained by an interaction between genetic factors and their alteration. Gallstones and chronic cholecystitis are important risk factors in the formation of gallbladder malignancies. Factors such as chronic bacterial infection, primary sclerosing cholangitis, an anomalous junction of the pancreaticobiliary duct, and several types of gallbladder polyps are associated with a higher risk of gallbladder cancer. There is also an interesting correlation between risk factors and the histological type of cancer. However, despite theoretical risk factors, only a third of gallbladder carcinomas are recognized preoperatively. In most patients, the tumor is diagnosed by the pathologist after a routine cholecystectomy for a benign disease and is termed ‘‘incidental or occult gallbladder carcinoma’’ (IGBC). A cholecystectomy is performed frequently due to the minimal invasiveness of the laparoscopic technique. Therefore, the postoperative diagnosis of potentially curable early-stage disease is more frequent. A second radical re-resection to complete a radical cholecystectomy is required for several IGBCs. However, the literature and guidelines used in different countries differ regarding the radicality or T-stage criteria for performing a radical cholecystectomy. The NCCN guidelines and data from the German registry (GR), which records the largest number of incidental gallbladder carcinomas in Europe, indicate that carcinomas infiltrating the muscularis propria or beyond require radical surgery. According to GR data and current literature, a wedge resection with a combined dissection of the lymph nodes of the hepatoduodenal ligament is adequate for T1b and T2 carcinomas. The reason for a radical cholecystectomy after simple CE in a formally R0 situation is either occult invasion or hepatic spread with unknown lymphogenic dissemination. Unfortunately, there are diverse interpretations and practices regarding stage-adjusted therapy for gallbladder carcinoma. The current data suggest that more radical therapy is warranted.

Cancer in immigrants as a pointer to the causes of cancer

The early cancer studies on immigrants, which started to appear some 50 years ago, showed that the incidence in cancers changes to the level of the new host country in one or two generations. These findings were fundamental to the understanding of the environmental etiology of human cancer. Many immigrant groups originate from countries with no cancer registration, and, hence, the immigrant studies may provide estimates on the indigenous cancer rates. The Swedish Family-Cancer Database has been an important source of data for immigrant studies on various diseases. The Database covers the Swedish population of the past 100 years, and it records the country of birth for each subject. A total of 1.79 million individuals were foreign born, Finns and other Scandinavians being the largest immigrant groups. Over the course of years, some 30 publications have appeared relating to cancer in immigrants. In the present article, we will review more recent immigrant studies, mainly among Swedish immigrants, on all cancers and emphasize the differences between ethnic groups. In the second part, we discuss the problem of reliable registration of cancer and compare cancer incidence among non-European immigrants with cancer incidence in countries of origin, as these have now active cancer registries. We discuss the experiences in cancer registration in Morocco and Egypt. We show the usefulness and limitations in predicting cancer incidence in the countries of origin.

Hispano-Americans in Europe: what do we know about their health status and determinants? A scoping review

Background

Policy makers and health practitioners are in need of guidance to respond to the growing geographic mobility of Hispano-American migrants in Europe. Drawing from contributions from epidemiology, social sciences, demography, psychology, psychiatry and economy, this scoping review provides an up-to-date and comprehensive synthesis of studies addressing the health status and determinants of this population. We describe major research gaps and suggest specific avenues of further inquiry.

Methods

We identified systematically papers that addressed the concepts “health” and “Hispano Americans” indexed in five data bases from Jan 1990 to May 2014 with no language restrictions. We screened the 4,464 citations retrieved against exclusion criteria and classified 193 selected references in 12 thematic folders with the aid of the reference management software ENDNOTE X6. After reviewing the full text of all papers we extracted relevant data systematically into a table template to facilitate the synthesising process.

Results

Most studies focused on a particular disease, leaving unexplored the interlinkages between different health conditions and how these relate to legislative, health services, environmental, occupational, and other health determinants. We elucidated some consistent results but there were many heterogeneous findings and several popular beliefs were not fully supported by empirical evidence. Few studies adopted a trans-national perspective and many consisted of cross-sectional descriptions that considered “Hispano-Americans” as a homogeneous category, limiting our analysis. Our results are also constrained by the availability and varying quality of studies reviewed.

Conclusions

Burgeoning research has produced some consistent findings but there are huge gaps in knowledge. To prevent unhelpful generalisations we need a more holistic and nuanced understanding of how mobility, ethnicity, income, gender, legislative status, employment status, working conditions, neighbourhood characteristics and social status intersect with demographic variables and policy contexts to influence the health of the diverse Hispano-American populations present in Europe.

Electronic supplementary material

The online version of this article (doi:10.1186/s12889-015-1799-x) contains supplementary material, which is available to authorized users.

Aspects on gallbladder cancer in 2014

PURPOSE OF REVIEW

To discuss some key issues involved in the management of gallbladder cancer (GBC).

RECENT FINDINGS

The decline in incidence and mortality of GBC began decades before the introduction of laparoscopic surgery. In consecutive autopsies and in cases in which cholelithiasis was present, the incidence of gallbladder carcinoma is 3-4%. A number of genetic alterations have been identified in the different stages of GBC and they support the morphological evidence of two pathways by which tumors develop. Some of these genetic changes are associated with particular risk factors. All management of GBC and all comparisons of treatment results from different centers must be based on the stages.

SUMMARY

Simple cholecystectomy is the adequate treatment for T1a GBC. Lymph node excision improved survival in patients with T2 lesions. Radical en bloc resection of T2 tumors offers greater benefit over conventional cholecystectomy alone in terms of greater long-term survival times. Provided that negative surgical margins are secured, hepatectomy and lymph node resection can, therefore, be withheld in most cases in the surgical treatment of pT2 GBC. With improvements in surgical and anesthetic techniques, aggressive surgery has proven to be performed with safety.

Hepatitis B screening and vaccination strategies for newly arrived adult Canadian immigrants and refugees: a cost-effectiveness analysis

BACKGROUND

Immigrants have increased mortality from hepatocellular carcinoma as compared to the host populations, primarily due to undetected chronic hepatitis B virus (HBV) infection. Despite this, there are no systematic programs in most immigrant-receiving countries to screen for chronic HBV infection and immigrants are not routinely offered HBV vaccination outside of the universal childhood vaccination program.

METHODS AND FINDINGS

A cost-effective analysis was performed to compare four HBV screening and vaccination strategies with no intervention in a hypothetical cohort of newly-arriving adult Canadian immigrants. The strategies considered were a) universal vaccination, b) screening for prior immunity and vaccination, c) chronic HBV screening and treatment, and d) combined screening for chronic HBV and prior immunity, treatment and vaccination. The analysis was performed from a societal perspective, using a Markov model. Seroprevalence estimates, annual transition probabilities, health-care costs (in Canadian dollars), and utilities were obtained from the published literature. Acute HBV infection, mortality from chronic HBV, quality-adjusted life years (QALYs), and costs were modeled over the lifetime of the cohort of immigrants. Costs and QALYs were discounted at a rate of 3% per year. Screening for chronic HBV infection, and offering treatment if indicated, was found to be the most cost-effective intervention and was estimated to cost $40,880 per additional QALY gained, relative to no intervention. This strategy was most cost-effective for immigrants < 55 years of age and would cost < $50,000 per additional QALY gained for immigrants from areas where HBV seroprevalence is ≥ 3%. Strategies that included HBV vaccination were either prohibitively expensive or dominated by the chronic HBV screening strategy.

CONCLUSIONS

Screening for chronic HBV infection from regions where most Canadian immigrants originate, except for Latin America and the Middle East, was found to be reasonably cost-effective and has the potential to reduce HBV-associated morbidity and mortality.

Incidence of hereditary amyloidosis and autoinflammatory diseases in Sweden: endemic and imported diseases

Background

Amyloidoses are a heterogeneous group of progressive diseases caused by tissue deposition of misfolded proteins. According to the International Classification of Diseases, hereditary amyloidosis is divided into neuropathic and non-neuropathic forms. In Sweden, neuropathic heredofamilial amyloidosis has been identified as familial amyloidotic polyneuropathy (FAP), a fatal disease that is treated by liver transplantation. The non-neuropathic form includes familial autoinflammatory diseases. As no incidence data on these hereditary diseases are available and as even diagnostic data on non-neuropathic forms are lacking we determined the incidence of these diseases and characterized non-neuropathic conditions.

Methods

Patients were identified using data from the Swedish Hospital Discharge Register and from the Outpatient Register for 2001 through 2008. All patients discharged with hereditary amyloidosis diagnoses were included and standardized incidence rates were calculated.

Results

Non-neuropathic disease was diagnosed in 210 patients, with an incidence of 2.83 per million. FAP was diagnosed in 221 patients, with an incidence of 2.02 per million. Two northern provinces that are home to 5% of the Swedish population accounted for 77% of FAP cases; the incidence in one of them, West Bothnia, was 100 times that in the rest of Sweden. Approximately 98% of non-neuropathic disease patients were immigrants, most of whom were from the Eastern Mediterranean area. Young Syrian descendants had the highest incidence rate, which was over 500-fold higher than that in individuals with Swedish parents. Even the early onset of these conditions identified them as familial autoinflammatory diseases.

Conclusions

FAP cases were highly concentrated in the two northernmost provinces. Non-neuropathic familial autoinflammatory diseases were of early-onset and immigrant origin most likely related to periodic fever syndromes. Paradoxically, FAP has remained endemic, in spite of population movements within the country, while familial autoinflammatory diseases, with an incidence exceeding that of FAP, were brought into the country as a result of immigration mainly from the Eastern Mediterranean area.

Hepatitis B virus in the Maghreb region: from epidemiology to prospective research

Hepatitis B virus (HBV) represents an important health problem in the Maghreb countries, Algeria, Libya, Mauritania, Morocco and Tunisia, but no detailed synthesis of its epidemiology is available. In this review, we systematically searched for data about HBV in the Maghreb in peer-reviewed databases and included in our analysis works written in English and French, as well as institutional reports and regional conference meeting abstracts. We estimated national and regional prevalence of chronic HBV infection. In addition, we discuss molecular features of the viral strains circulating in the region. Data analysis suggests that in the Maghreb region HBs antigen carriage concerns 1.8-4.9% of the population for an estimated number of 2.7 million persons. Genotype D, subtype D7, is predominant and mutations in the precore region of HBV genome are highly prevalent. This epidemiological situation requires obviously widespread active interventions for prevention and control. In addition, anti-hepatitis B vaccination programme should be applied with the utmost discipline in the five countries considered in this present review. This systematic review will, hopefully, increase knowledge at disposal of Public Health authorities, enabling better resource allocation and healthcare delivery. The present synthesis intends to stimulate policies aiming at preventing the spread of HBV, keeping in mind that eradication of the virus from Maghrebi populations should be the ultimate objective of Public Health authorities.

Hepatitis C virus infection in the Maghreb region

Hepatitis C is a global health problem with a worldwide prevalence of about 3% (around 170 million people). Hepatitis C virus (HCV) is major concern in the Maghreb countries, Algeria, Libya, Mauritania, Morocco, and Tunisia, but no detailed description of its epidemiology in the region is available. In the present review, a systematic search was undertaken covering HCV data available in peer-reviewed databases as well as institutional reports and regional conference meeting abstracts from the Maghreb countries. Reports written in English and French were included in this analysis. Estimates of national and regional prevalence of HCV infection (based on anti-HCV antibody) and of the size of patient populations were performed. In addition, the molecular features of the circulating viral strains in the region are discussed. A substantial proportion, 1.2-1.9% of the Maghreb inhabitants, have anti-HCV antibodies. Genotype 1b predominates among viral strains in all countries except in Libya, where genotype 4 is dominant as in neighboring Egypt. This epidemiological situation is of significant concern, and requires urgent, broad, and active intervention for the prevention and control of HCV. More specifically, the application of state-of-the-art hygiene procedures and rigorous controls in medical disciplines such as hemodialysis, transfusion, endoscopic procedures, and dentistry is necessary to reduce significantly the number of new infections in the region.

Socioeconomic status and hepatocellular carcinoma in the United States

BACKGROUND

Hepatocellular carcinoma (HCC) has a poor prognosis and, unlike most cancers, HCC incidence and mortality rates are increasing in the United States. While risk is known to vary among different racial and ethnic groups, less is known about the variability of risk within these groups by neighborhood socioeconomic status (SES).

METHODS

HCC cases diagnosed in the Surveillance, Epidemiology and End Results (SEER) 11 cancer registries between 1996 and 2007, and the population of the SEER 11 catchment areas was studied. Analyses were conducted to compare census tract area family poverty, educational attainment, and unemployment by race and ethnicity. A multiple linear regression model, weighted by the number of cases and the number of individuals in each census tract, with adjustment for registry, was used to calculate mean differences in area-level attributes between HCC cases and the population.

RESULTS

HCC cases in most racial/ethnic groups had lower mean neighborhood-level measures of SES than their referent population. An exception was seen among Hispanics. Comparing white cases with cases of other racial groups and to Hispanics, white cases lived in neighborhoods with less family poverty, fewer high-school dropouts, and lower unemployment. Compared with white cases, Asian and Pacific Islander and Hispanic cases lived in neighborhoods with a higher percentage of foreign-born population.

CONCLUSIONS

Low neighborhood-level SES and immigrant status may be associated with greater risk of HCC within specific racial and ethnic groups.

IMPACT

These findings could help to focus control resources for HCC toward the most affected communities.

Incidence of celiac disease among second-generation immigrants and adoptees from abroad in Sweden: evidence for ethnic differences in susceptibility

BACKGROUND AND AIMS

The incidence of celiac disease (CD) shows large, worldwide variation. However, whether its causes are environmental (gluten-containing diet) or genetic (specific haplotype) have not been established. The aim of the present study is to examine the incidence of CD among second-generation immigrants and adoptees from abroad to disentangle genetic/ethnic versus environmental influences (assuming that immigrants have similar gluten exposures to native Swedes, and thus differ from them only in terms of their genetic background).

METHODS

Second-generation immigrants and adoptees from abroad were identified in the MigMed 2 Database and were followed until diagnosis of CD, death, or the end of study. Standardized incidence ratios (SIRs) were calculated among these immigrants with native Swedes as the reference group.

RESULTS

A total of 1,050,569 children were defined as second-generation immigrants and the overall SIR of CD (SIR = 0.89, 95% confidence interval 0.84-0.94) was significantly lower than that of native Swedes. The incidence of CD among children with parents from Western, Eastern, and Northern European countries was similar to that in native Swedes, but was lower for those with parents from low-prevalence countries, especially Eastern and Southeast Asian countries. A total of 51,557 children born in foreign countries were adopted by Swedes. Adoptees from Eastern Asia had a significantly decreased SIR of CD.

CONCLUSIONS

The decreased incidence of CD in second-generation immigrants and some groups of adoptees from abroad strongly suggests that ethnic genetic heterogeneity may contribute to the worldwide variation in CD incidence.

Cancer risk diversity in non-western migrants to Europe: An overview of the literature

BACKGROUND

Cancer risk varies geographically and across ethnic groups that can be monitored in cancer control to respond to observed trends as well as ensure appropriate health care. The study of cancer risk in immigrant populations has great potential to contribute new insights into aetiology, diagnosis and treatment of cancer. Disparities in cancer risk patterns between immigrant and autochthonous populations have been reported many times, but up to now studies have been heterogeneous and may be discordant in their findings. The aim of this overview was to compile and compare studies on cancer occurrence in migrant populations from non-western countries residing in Western Europe in order to reflect current knowledge in this field and to appeal for further research and culturally sensitive prevention strategies.

METHODS

We included 37 studies published in the English language between 1990 and April 2010 focussing on cancer in adult migrants from non-western countries, living in the industrialised countries of the European Union. Migrants were defined based on their country of birth, ethnicity and name-based approaches. We conducted a between-country comparison of age-adjusted cancer incidence and mortality in immigrant populations with those in autochthonous populations.

FINDINGS

Across the board migrants from non-western countries showed a more favourable all-cancer morbidity and mortality compared with native populations of European host countries, but with considerable site-specific risk diversity: Migrants from non-western countries were more prone to cancers that are related to infections experienced in early life, such as liver, cervical and stomach cancer. In contrast, migrants of non-western origin were less likely to suffer from cancers related to a western lifestyle, e.g. colorectal, breast and prostate cancer.

DISCUSSION

Confirming the great cancer risk diversity in non-western migrants in and between different European countries, this overview reaffirms the importance of exposures experienced during life course (before, during and after migration) for carcinogenesis. Culturally sensitive cancer prevention programmes should focus on individual risk patterns and specific health care needs. Therefore, continuously changing environments and subsequently changing risks in both migrant and autochthonous populations need to be observed carefully in the future.