Cancer incidence among Canadian immigrants, 1980-1998: results from a national cohort study

Adherence and Correlates of Cervical Cancer Screening Among East African Immigrant Women in Washington State

INTRODUCTION

Cervical cancer screening (CCS) among East African immigrants (EAI) in the USA is under explored. This study aimed to investigate adherence to CCS and its correlates among EAI.

METHODS

We identified 1664 EAI women (25-65 years) with ≥ 1 primary care clinic visit(s) between 2017 and 2018, using University of Washington (UW) Medicine electronic health record data. CCS adherence was defined as Pap testing within 3 years or human papillomavirus/Pap co-testing within 5 years. We used Poisson regression with robust standard errors to cross-sectionally estimate associations with correlates of adherence. Twelve-month screening uptake was also evaluated among overdue women.

RESULTS

CCS adherence was 63%. Factors associated with higher adherence included older age (adjusted prevalence ratios [APRs]:1.47:95%CI:1.14-1.90, 1.38:95%CI:1.05-1.80, respectively, for ages 30-39 and 40-49 vs 25-29 years), longer duration of care at UW Medicine (APR:1.22:95%CI:1.03-1.45, comparing > 10 vs < 5 years), higher visit frequency (APR:1.23:95%CI:1.04-1.44, 1.46:95%CI:1.24-1.72, respectively, for 3-5 and ≥ 6 vs 1-2 visits), index visit in an obstetrics-gynecology clinic (APR:1.26:95%CI:1.03-1.55, vs family practice), having an assigned primary care provider (APR:1.35: 95%CI:1.02-1.79), breast cancer screening adherence (APR:1.66: 95%CI:1.27-2.17), and colorectal cancer screening adherence (APR:1.59:95%CI:1.24-2.03). Low BMI was associated with lower adherence (APR:0.50:95%CI:0.26-0.96, comparing < 18.5 kg/m2 vs 18.5-24.9 kg/m2). Among 608 (37%) overdue women, 9% were screened in the subsequent 12 months. Having commercial health insurance vs Medicare/Medicaid was associated with higher uptake (adjusted risk ratio:2.44:95%CI:1.15-5.18).

CONCLUSION

CCS adherence among EAI was lower than the national average of 80%. Interventions focused on increasing healthcare access/utilization or leveraging healthcare encounters to address barriers could increase CCS in EAIs.

Global, Regional, and National Trends in Incidence and Mortality of Primary Liver Cancer and Its Underlying Etiologies from 1990 to 2019: Results from the Global Burden of Disease Study 2019

OBJECTIVE

Primary liver cancer is not only one of the most common causes of cancer deaths but also the second most common cause of premature death worldwide. Understanding the trends in incidence and mortality of primary liver cancer and its etiologies is crucial for development of effective prevention and mitigation strategies. This study aimed to quantify the trends in incidence and mortality of primary liver cancer and its etiologies at the global, regional and national levels using data from Global Burden of Disease (GBD) study.

METHOD

Annual incident cases, deaths, age-standardized incidence rates (ASIRs), and age-standardized mortality rates (ASMRs) of primary liver cancer and its etiologies, including hepatitis B, hepatitis C, alcohol use, nonalcoholic steatohepatitis, and other causes, between 1990 and 2019 were collected from GBD study 2019. Percentage changes in incident cases and deaths and estimated annual percentage changes (EAPCs) in ASIRs and ASMRs of primary liver cancer and its etiologies were calculated to quantify their temporal trends. Correlations of EAPC in ASIRs and ASMRs with socio-demographic index (SDI) and universal health coverage index (UHCI) in 2019 were separately evaluated by Pearson correlation analyses.

RESULTS

Globally, the incident cases and deaths of primary liver cancer increased by 43.11% from 373 393 in 1990 to 534 365 in 2019 and 32.68% from 365 213 in 1990 to 484 584 in 2019, respectively. ASIR and ASMR of primary liver cancer decreased by an average of 2.23% (95% CI 1.83%, 2.63%) and 1.93% (95% CI 1.55%, 2.31%) per year between 1990 and 2019 worldwide, respectively. ASIRs and ASMRs of primary liver cancer varied between regions, with an increasing trend in ASIR (EAPC = 0.91; 95% CI 0.47, 1.35) and a stable trend in ASMR (EAPC = 0.42, 95% CI - 0.01, 0.85) of primary liver cancer in high SDI region between 1990 and 2019. Nearly half (91/204) of the countries suffered an increasing trend in ASIR of primary liver cancer and more than one-third (71/204) of the countries suffered an increasing trend in ASIRs of primary liver cancer from all etiologies between 1990 and 2019 worldwide. Positive correlations of EAPC in ASIR and ASMR of primary liver cancer with SDI and UHCI were observed in nations with SDI ≥ 0.7 or UHCI ≥ 70.

CONCLUSION

Primary liver cancer remains a major public health concern globally, with an increasing trend in the numbers of incident cases and deaths in the past three decades. We observed an increasing trend in ASIR of primary liver cancer in nearly half of the countries and an increasing trend in ASIRs of primary liver cancer by etiology in more than one-third of the countries worldwide. In line with the Sustainable Development Goals, the identification and elimination of risk factors for primary liver cancer will be required to achieve a sustained reduction in liver cancer burden.

Global burden of primary liver cancer in 2020 and predictions to 2040

BACKGROUND & AIMS

The burden of liver cancer varies across the world. Herein, we present updated estimates of the current global burden of liver cancer (incidence and mortality) and provide predictions of the number of cases/deaths to 2040.

METHODS

We extracted data on primary liver cancer cases and deaths from the GLOBOCAN 2020 database, which includes 185 countries. Age-standardised incidence and mortality rates (ASRs) per 100,000 person-years were calculated. Cases and deaths up to the year 2040 were predicted based on incidence and mortality rates for 2020 and global demographic projections to 2040.

RESULTS

In 2020, an estimated 905,700 people were diagnosed with, and 830,200 people died from, liver cancer globally. Global ASRs for liver cancer were 9.5 and 8.7 for new cases and deaths, respectively, per 100,000 people and were highest in Eastern Asia (17.8 new cases, 16.1 deaths), Northern Africa (15.2 new cases, 14.5 deaths), and South-Eastern Asia (13.7 new cases, 13.2 deaths). Liver cancer was among the top three causes of cancer death in 46 countries and was among the top five causes of cancer death in 90 countries. ASRs of both incidence and mortality were higher among males than females in all world regions (male:female ASR ratio ranged between 1.2-3.6). The number of new cases of liver cancer per year is predicted to increase by 55.0% between 2020 and 2040, with a possible 1.4 million people diagnosed in 2040. A predicted 1.3 million people could die from liver cancer in 2040 (56.4% more than in 2020).

CONCLUSIONS

Liver cancer is a major cause of death in many countries, and the number of people diagnosed with liver cancer is predicted to rise. Efforts to reduce the incidence of preventable liver cancer should be prioritised.

LAY SUMMARY

The burden of liver cancer varies across the world. Liver cancer was among the top three causes of cancer death in 46 countries and was among the top five causes of cancer death in 90 countries worldwide. We predict the number of cases and deaths will rise over the next 20 years as the world population grows. Primary liver cancer due to some causes is preventable if control efforts are prioritised and the predicted rise in cases may increase the need for resources to manage care of patients with liver cancer.

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.

The mean attributable health care costs associated with hepatitis B virus in Ontario, Canada: A matched cohort study

BACKGROUND: No Canadian studies examined the economic impact of hepatitis B virus (HBV) using population-based, patient-level data. We determined attributable costs associated with HBV from a health care payer perspective. METHODS: We conducted an incidence-based, matched cohort, cost-of-illness study. We identified infected subjects (positive HBV surface antigen, DNA, or e-antigen) between 2004 and 2014, using health administrative data. The index date was the first positive specimen. The cohort was organized into three groups: no HBV-related complications, HBV-related complications before index date, and HBV-related complications post-index date. To evaluate costs (2017 Canadian dollars), we adopted the phase-of-care approach defining six phases. Mean attributable costs were determined by evaluating mean differences between matched pairs. Hard match variables were sex, age group, index year, rurality, neighbourhood income quintile, comorbidities, and immigrant status. Costs were combined with crude survival data to calculate 1-, 5-, and 10-year costs. RESULTS: We identified 41,469 infected subjects with a mean age of 44.2 years. The majority were males (54.7%), immigrants (58.4%), and residents of major urban centres (96.8%). Eight percent had HBV-related complications before index date and 11.5% had them post index date. Across groups, mean attributable costs ranged from CAD-$27–$19 for pre-diagnosis, CAD$167–$1,062 for initial care, CAD$53–$407 for continuing care, CAD$1,033 for HBV-related complications, $304 for continuing care for complications, and CAD$2,552–$4,281 for final care. Mean cumulative 1-, 5-, and 10-year costs ranged between CAD$253–$3,067, $3,067–$20,349, and CAD$6,128–$38,968, respectively. CONCLUSIONS: HBV is associated with long-term economic burden. These results support decision-making on HBV prevention and monitoring strategies.

Preventive Cancer Screening Among Resettled Refugee Women from Muslim-Majority Countries: A Systematic Review

As refugee populations continue to age in the United States, there is a need to prioritize screening for chronic illnesses, including cancer, and to characterize how social and cultural contexts influence beliefs about cancer and screening behaviors. This study examines screening rates and socio-cultural factors influencing screening among resettled refugee women from Muslim-majority countries of origin. A systematic and integrative review approach was used to examine articles published from 1980 to 2019, using PubMed, CINAHL, and PsycINFO. A total of 20 articles met the inclusion criteria. Cancer screening rates among refugee women are lower when compared to US-born counterparts. Social and cultural factors include religious beliefs about cancer, stigma, modesty and gender roles within the family context. The findings of this review, suggest that resettled refugee women underutilize preventive services, specifically mammography, Pap test and colonoscopy screening, and whose perceptions and behaviors about cancer and screening are influenced by social and cultural factors.

Migration Medicine

Migration is increasing and practitioners need to be aware of the unique health needs of this population. The prevalence of infectious diseases among migrants varies and generally mirrors that of their countries of origin, but is modified by the circumstance of migration, the presence of pre-arrival screening programs and post arrival access to health care. To optimize the health of migrants practitioners; (1) should take all opportunities to screen migrants at risk for latent infections such as tuberculosis, chronic hepatitis B and C, HIV, strongyloidiasis, schistosomiasis and Chagas disease, (2) update routine vaccines in all age groups and, (3) be aware of "rare and tropical infections" related to migration and return travel.

The influence of ethnicity on disease outcome in patients with chronic hepatitis B infection

Since the cultural diversity in Western Europe is growing, this study assessed whether foreign‐born chronic hepatitis B (CHB) patients have more cirrhosis than Dutch‐ or Belgian‐born patients, with a main focus on the Turkish population. Baseline characteristics (eg, socioeconomic status [SES]), biological characteristics, and disease outcome (eg, cirrhosis) were collected for all patients. Between December 2009 and January 2015, 269 CHB patients participated from the outpatient departments of three hospitals in the Netherlands, Belgium, and Turkey. Out of the 269 CHB patients, 210 were foreign‐born and 59 were Dutch‐ or Belgian‐born. Compared with Dutch‐ or Belgian‐born patients, foreign‐born patients had a higher prevalence of low SES (58% vs 31%; P = 0.001) and cirrhosis (27% vs 10%; P = 0.007). Among the Turkish population, there were no significant differences regarding the prevalence of low SES (73% vs 61%; P = 0.170), alcohol abuse (1% vs 5%; P = 0.120), anti‐hepatitis C virus positivity (4% vs 0%; P = 0.344), anti‐hepatitis D virus positivity (1% vs 6%; P = 0.297), and cirrhosis (37% vs 27%; P = 0.262) between patients (n = 102) living in Turkey (local) and Turkish CHB (n = 38) patients living in the Netherlands or Belgium (immigrant). In multivariate analysis, low SES (odds ratio, 5.7; 95% confidence interval, 2.3‐14.5; P < 0.001) was associated with cirrhosis. In this study, foreign‐born CHB patients were associated with more advanced HBV‐related liver disease with 27% having cirrhosis. However, ethnicity was not associated with cirrhosis when SES was included in the multivariate analysis. The similar prevalence of cirrhosis in local Turkish compared to immigrant Turkish CHB patients is novel and warrants further investigation.

Foreign‐born individuals have a higher prevalence of cirrhosis than Dutch‐ or Belgian‐ born individuals

There was a lower socioeconomic status in the foreign‐born individuals

No difference in the prevalence of cirrhosis was seen between the local and immigrant Turkish population

Socioeconomic status and not ethnicity was an independent predictor of cirrhosis

Higher risk of gastric cancer among immigrants to Ontario: a population-based matched cohort study with over 2 million individuals

BACKGROUND

The risk of gastric carcinoma (GC) varies around the world and between females and males. We aimed to compare the risk of GC among immigrants to Ontario, Canada, to the risk of GC in its general population.

METHODS

This was a retrospective population-based matched cohort study from 1991 to 2014. We identified immigrants who were first eligible for the Ontario Health Insurance Plan at age 40 years or older, and matched 5 controls by year of birth and sex. We calculated crude rates and relative rates of GC stratified by sex. We modeled GC hazard using multivariable Cox proportional hazards regression, where a time-varying coefficient was incorporated to examine changes in the association of immigrant status with GC hazard over time.

RESULTS

Among females, 415 GC cases were identified among 209,843 immigrants and 1872 among 1,049,215 controls. Among males, 596 GC cases were identified among 191,792 immigrants and 2998 among 958,960 controls. Comparing immigrants from East Asia and Pacific with the controls, the crude relative rate of GC was 1.54 for females and 1.32 for males. The adjusted hazard ratio (HR) for GC among female immigrants was 1.29 [95% confidence interval (CI) 1.12, 1.48] within 10 years and 1.19 (1.01, 1.40) beyond 10 years; for males, the HR was 1.17 (1.04, 1.31) within 10 years and 1.00 (0.87, 1.15) beyond 10 years.

CONCLUSION

The risk of GC among immigrants is elevated. Although high-risk immigrant populations in Ontario have been identified, further knowledge is required before a program of GC prevention that is targeted to them can be planned.

Barriers to cervical cancer screening faced by immigrants: a registry-based study of 1.4 million women in Norway

Background

Immigrants from certain low- and middle-income countries are more prone to cancers attributed to viral infections in early life. Cervical cancer is caused by human papillomavirus but is highly preventable by regular screening. We assessed participation among immigrants in a population-based cervical screening programme and identified factors that predicted non-adherence within different immigrant groups.

Methods

We used data from several nationwide registries. The study population consisted of 208 626 (15%) immigrants and 1 157 223 (85%) native Norwegians. Non-adherence was defined as no eligible screening test in 2008–12. We estimated prevalence ratios with 95% confidence intervals (CIs) for factors associated with non-adherence by modified Poisson regression.

Results

In total, 52% of immigrants were not screened. All immigrants showed 1.72 times higher non-adherence rates (95% CI 1.71–1.73) compared with native Norwegian women when adjusted for age and parity. The proportion of non-adherent immigrants varied substantially by region of origin and country of origin. Being unemployed or not in the workforce, being unmarried, having low income and having a male general practitioner was associated with non-adherence regardless of region of origin. Living <10 years in Norway was an evident determinant of non-adherence among most but not all immigrant groups.

Conclusions

An increasing proportion of immigrants and low screening participation among them pose new public health challenges in Europe. Immigrants are diverse in terms of their sociodemographic attributes and screening participation. Tailored information and service delivery may be necessary to increase cancer screening among immigrants.

Incidence of breast and colorectal cancer among immigrants in Ontario, Canada: a retrospective cohort study from 2004-2014

Background

Studies have shown that morbidity and mortality rates due to cancer among recent immigrants are lower than those among the native-born population. The objectives of this study were to describe the incidence of colorectal and breast cancer among immigrants from major regions of the world compared to Canadian-born residents of the province of Ontario and to examine the role of length of stay and neighborhood income.

Methods

Retrospective cohort study including all individuals 18 years and over residing in Ontario from 2004 to 2014. Age-standardized incidence rates (ASIR) were calculated for immigrants from each world region versus Canadian-born residents and stratified by neighborhood income quintile and length of stay. Binomial regression analysis was used to determine the association of neighbourhood income, length of stay, and location of birth with colorectal and breast cancer incidence.

Results

Canadian immigrants born in South Asia had the lowest colorectal and breast cancer incidence (colorectal: women: ASIR = 0.14; men: ASIR = 0.18; breast: ASIR = 1.00) compared to long-term residents during the study period (colorectal: women: ASIR = .57; men: ASIR = .72; breast cancer ASIR = 1.61). In multivariate analyses, neighboorhood income did not consistently play a significant role in colorectal cancer incidence; however higher neighbourhood income was a risk factor for breast cancer among immigrant women (adjusted relative risk for highest neighboorhood income quintile versus lowest income quintile =1.21, 95% CI = 1.18–1.24). Increased length of stay was associated with higher risk of cancer. After adjusting for age, neighborhood income, and length of stay, those born in Europe and Central Asia had the highest risk of colorectal cancer compared to those born in East Asia and Pacific and those born in the Middle East had the greatest additional risk of breast cancer.

Conclusions

After correcting for age, breast and colorectal cancer incidence rates among immigrants differ according to their region of birth and recent immigrants to Ontario have lower colorectal and breast cancer incidence rates than their native-born peers. However, those advantages diminish over time. These findings call for Ontario to generate tools and interventions to maintain the health of the immigrant population, particularly for those groups with a higher incidence of cancer.

Cervical cancer screening in immigrant women in Italy: a survey on participation, cytology and histology results

Cervical cancer screening programmes in Italy actively invite all 25-64-year-old resident women for the Pap test every 3 years irrespective of their citizenship. Immigrant women come from countries where screening is absent or poorly implemented and the prevalence of human papillomavirus is often high. These women therefore have significant risk factors for cervical cancer. The Italian Group for Cervical Cancer Screening promoted a survey of all the screening programmes on the participation and the positivity and detection rates in Italian and foreign women in 2009-2011. Aggregated data for participation, cytology results, compliance with colposcopy and histology results were collected, distinguishing between women born in Italy and abroad. All comparisons were age adjusted. Forty-eight programmes out of 120 participated in the immigrant survey, with 3 147 428 invited and 1 427 412 screened Italian women and 516 291 invited and 205 948 screened foreign women. Foreign women had a slightly lower participation rate compared with Italians (39.9 vs. 45.4%), whereas compliance with colposcopy was similar (90%). Foreigners showed a higher risk of pathological findings than Italians: cytology positivity [relative risk (RR)=1.25, 95% confidence interval (CI) 1.24-1.27] and detection rate for cervical intraepithelial neoplasia grade 2 (CIN2) (RR=1.39, 95% CI 1.31-1.47), CIN3 (RR=2.07, 95% CI 1.96-2.18) and cancer (RR=2.68, 95% CI 2.24-3.22). The ratio between cancer and CIN was higher in immigrants (0.06 vs. 0.04, P<0.01). Foreign women had a higher risk of cervical precancer and cancer. Because of their high risk and because opportunistic screening does not cover this often disadvantaged group, achieving high participation in screening programmes for foreigners is critical to further reducing the cervical cancer burden in Italy.

Risk of colorectal cancer among immigrants to Ontario, Canada

Background

The risk of colorectal cancer (CRC) varies around the world and between females and males. We aimed to compare the risk of CRC among immigrants to Ontario, Canada, to its general population.

Methods

We used an exposure-control matched design. We identified persons in the Immigration, Refugees and Citizenship Canada Permanent Resident Database with first eligibility for the Ontario Health Insurance Plan between July 1, 1991 and June 30, 2008 at age 40 years or older, and matched five controls by year of birth and sex on the immigrant’s first eligibility date. We identified CRC from the Ontario Cancer Registry between the index date and December 31, 2014. All analyses were stratified by sex. We calculated crude and relative rates of CRC. We estimated risk of CRC over time by the Kaplan-Meier method and compared immigrants to controls in age and sex stratified strata using log-rank tests. We modeled the hazard of CRC using Cox proportional hazards regression, accounting for within-cluster correlation by a robust sandwich variance estimation approach, and assessed an interaction with time since eligibility.

Results

Among females, 1877 cases of CRC were observed among 209,843 immigrants, and 16,517 cases among 1,049,215 controls; the crude relative rate among female immigrants was 0.623. Among males, 1956 cases of CRC were observed among 191,792 immigrants and 18,329 cases among 958,960 controls; the crude relative rate among male immigrants was 0.582.. Comparing immigrants to controls in all age and sex stratified strata, the log rank test p < 0.0001 except for females aged > = 75 years at index, where p = 0.01. The age-adjusted hazard ratio (HR) for CRC among female immigrants was 0.63 (95% CI 0.59, 0.67) during the first 10 years, and 0.66 (95% CI 0.59, 0.74) thereafter. Among male immigrants the age-adjusted HR = 0.55 (95% CI 0.52, 0.59) during the first 10 years and increased to 0.63 (95% CI 0.57, 0.71) thereafter. The adjusted HR > = 1 only among immigrants born in Europe and Central Asia.

Conclusions

The risk of CRC among immigrants to Ontario relative to controls varies by origin and over time since immigration.

Are immigrants healthier than native-born Canadians? A systematic review of the healthy immigrant effect in Canada

OBJECTIVES

Immigrants are typically healthier than the native-born population in the receiving country and also tend to be healthier than non-migrants in the countries of origin. This foreign-born health advantage has been referred to as the healthy immigrant effect (HIE). We examined evidence for the HIE in Canada.

DESIGN

We employed a systematic search of the literature on immigration and health and identified 78 eligible studies. We used a narrative method to synthesize the HIE across different stages of the life-course and different health outcomes within each stage. We also examined the empirical evidence for positive selection and duration effects - two common explanations of migrants' health advantage and deterioration, respectively.

RESULTS

We find that the HIE appears to be strongest during adulthood but less so during childhood/adolescence and late life. A foreign-born health advantage is also more robust for mortality but less so for morbidity. The HIE is also stronger for more recent immigrants but further research is needed to determine the critical threshold for when migrants' advantage disappears. Positive selection as an explanation for the HIE remains underdeveloped.

CONCLUSIONS

There is an absence of a uniform foreign-born health advantage across different life-course stages and health outcomes in Canada. Nonetheless, it remains the case that the HIE characterizes the majority of contemporary migrants since Canada's foreign-born population consists mostly of core working age adults.

Cancer and the healthy immigrant effect: a statistical analysis of cancer diagnosis using a linked Census-cancer registry administrative database

BACKGROUND

A large volume of research has been published on both the socio economic and demographic determinants of cancer and on the health of immigrants and minority groups. Yet because of data limitations, little research examines differences in the occurrence of cancer incidence between immigrants and non-immigrants and among immigrants defined by region of birth and time in the host country. In particular it is not known whether a healthy immigrant effect is present for cancer and if so, whether this advantage is lost with additional years of residence in the host country.

METHODS

This paper uses a large data file from Statistics Canada that links Census information on immigrant status, socioeconomic status including educational attainment, and other person-level information with administrative data on cancer and mortality over a continuous 13 year period of observation. It estimates discrete and continuous time duration models to identify differences in cancer diagnosis by immigrant subgroup after controlling for a variety of potential confounders. Differences in historical smoking behavior are not observable at the individual level in the dataset but are accounted for indirectly using various methods.

RESULTS

Results in general confirm the existence of a healthy immigrant effect for cancer in that, overall, recent immigrants to Canada are significantly less likely than otherwise comparable non-immigrant Canadians to be diagnosed with any cancer and the most common forms of cancer by site. As well, this gap appears to decline with additional years in Canada for immigrant men and women, eventually converging to Canadian-born levels. Differentiating among immigrant subgroups by period of arrival and country of birth reveals significant variation across immigrant subgroups, with immigrant men and women from developing countries typically having a lower likelihood of being diagnosed with cancer than immigrants from the US, UK and continental Europe. As well, controlling for immigrant heterogeneity this way weakens the conclusion that the gap narrows with years in Canada. Immigrant men overall continue to exhibit convergence to Canadian-born levels for diagnosis of any cancer and for prostate cancer, while immigrant women exhibit narrowing over time only for breast cancer. Although smoking behavior is not directly observed, controlling for subgroup-specific lifetime smoking behavior using survey data has only a relatively minor effect on the estimated differences.

CONCLUSIONS

The specificity of the results by cancer type, gender, immigrant status and ethnicity provides useful guidance for future research by helping to narrow the possible channels through which social and economic characteristics may be affecting cancer incidence.

Imported Disease Screening Prior to Chemotherapy and Bone Marrow Transplantation for Oncohematological Malignancies

Reactivation of latent imported infections has been periodically reported in migrant patients undergoing immunosuppression. We performed a prospective study at Vall d'Hebron University Hospital (Barcelona, Spain). Migrant patients over 16 years with the diagnosis of any oncohematologic disease were included. Patients were tested for soil-transmitted helminths, hepatitis virus, and human immunodeficiency virus, Treponema pallidum, human T-cell lymphotropic virus, latent tuberculosis infection, Toxoplasma spp., Plasmodium infection, Schistosoma spp., Trypanosoma cruzi infection, Leishmania spp., and dimorphic fungi. Patients were treated and followed for 1 year to assess reactivation. A total of 42 patients were included in this study. Median age was 39 (31-51) years. Twenty-five (59.5%) patients were women. More than half of the patients were of Latin American origin. Sixteen patients (38.1%) underwent hematopoietic stem cell transplantation. Of the patients, 71.4% had at least one imported infection. Patients with at least one positive result in the screening did not show any statistically significant association with the studied variables. We did not find any reactivation of the treated latent infections. After specific treatment we did not observe any reactivation. Screening of latent imported infections previous to an immunosuppressive treatment is easy to perform and it may be lifesaving.

Hospitalizations in Immigrants and Nonimmigrants Diagnosed With Chronic Hepatitis C Infection in Québec

BACKGROUND

 Rates of hospitalization due to chronic hepatitis C virus (HCV) are increasing in Canada and the United States. A large proportion of immigrants originate from countries with intermediate to high HCV prevalence but are not screened for HCV post-arrival and may therefore have increased risks of liver-related complications and hospitalization.

METHODS

 We conducted a retrospective cohort study of reported HCV cases in Québec, Canada, from 1998 to 2007 that were linked to administrative health databases. Outcomes included all-cause and liver-related hospitalizations and in-hospital days in immigrants compared with nonimmigrants adjusted for age, sex, and comorbidities.

RESULTS

 We identified 20 139 HCV cases; 9% (N = 1821) were immigrants. At diagnosis, immigrants were older (47.6 vs 43.2 years) and more likely to have hepatocellular carcinoma (HCC; 0.93% vs 0.31%), while nonimmigrants were 2- to 10-fold more likely to have substance use-related comorbidities. Mean time to HCV diagnosis after arrival was 9.8 years. Nonimmigrants had higher rates of all-cause hospitalization (adjusted rate ratio [95% confidence interval], 1.42 [1.35-1.47]), driven by mental illness and injury and/or poisoning. Unadjusted liver-related hospitalization rates were similar between cohorts. After adjustment, immigrant status was associated with lower rates of liver-related hospitalization (0.68 [.53-.88]).

CONCLUSIONS

 Higher burden of all-cause hospitalization in nonimmigrants likely reflects more prevalent behavioral comorbidities. Similar liver-related hospitalization rates appear to be driven by older age in immigrants who were more likely to have HCC at diagnosis possibly reflecting delayed HCV diagnosis. These findings suggest that earlier screening and treatment in immigrants could play an important role in preventing HCV complications in this population.

Hospital stays for hepatitis B or C virus infection or primary liver cancer among immigrants: a census-linked population-based cohort study

BACKGROUND

The recent increase in the incidence of primary liver cancer in Canada has been attributed to a higher proportion of immigrants from countries endemic for hepatitis B virus (HBV) and hepatitis C virus (HCV). We examined hospital discharges for liver disease in Canada, focusing on those for all liver-related diseases, HBV infection, HCV infection and primary liver cancer, by 3 immigration-related variables: immigration status, duration of residence in Canada and risk level of the source country.

METHODS

We calculated annualized crude and age-standardized rates of a hospital stay in Canada for HBV infection, HCV infection, primary liver cancer and all liver-related diseases using data from the 2006 Canadian census (long form) linked to the Canadian Institute for Health Information Discharge Abstract Database for fiscal years 2006/07 to 2008/09. We estimated the odds of a hospital stay using logistic regression for the 3 immigration-related variables, adjusting for sociodemographic indicators.

RESULTS

Immigrants were less likely than Canadian-born residents to be discharged with a diagnosis of any liver-related condition (odds ratio [OR] 0.83, 95% confidence interval [CI] 0.78-0.89); however, they were more likely to be discharged with a diagnosis of HBV infection (OR 2.02, 95% CI 1.57-2.60) and primary liver cancer (OR 1.43, 95% CI 1.22-1.68). There was a clear association between a hospital stay for HBV infection and immigration from HBV-endemic countries (OR 5.15, 95% CI 3.87-6.84) and between a stay for HCV infection and immigration from HCV-endemic countries (OR 2.98, 95% CI 1.74-5.11). Adjustment for low income status and urban residence did not change the results.

INTERPRETATION

Although the odds of a liver-related hospital stay were lower among immigrants than among those born in Canada, immigrants from countries at high risk for HBV infection, HCV infection and primary liver cancer were more likely than Canadian-born residents to have a corresponding liver-related hospital stay. These findings emphasize the importance of identifying immigrants with hepatitis and engaging them in care to prevent complications.

Can high overall human papillomavirus vaccination coverage hide sociodemographic inequalities? An ecological analysis in Canada

BACKGROUND

Human papillomavirus (HPV) vaccination programs have been implemented in more than 50 countries. These programs offer tremendous promise of reducing HPV-related disease burden. However, failure to achieve high coverage among high-risk groups may mitigate program success and increase inequalities. We examined sociodemographic inequalities in HPV vaccination coverage in 4 Canadian provinces (Quebec (QC), Ontario (ON), Manitoba (MB), British Columbia (BC)).

METHODS

We obtained annual HPV vaccination coverage of pre-adolescent girls at provincial and regional levels, from the start of programs to 2012/2013. Regions refer to administrative areas responsible for vaccine implementation and monitoring (there are 18/36/10/16 regions in QC/ON/MB/BC). We obtained regions' sociodemographic characteristics from Statistics Canada Census. We used univariate weighted linear regression to examine the associations between regions' sociodemographic characteristics and HPV vaccination coverage.

RESULTS

Provincial HPV vaccination coverage is generally high (QC:78%; ON:80%; MB:64%, BC:69%, 2012/13). QC had the highest provincial vaccination coverage since the program start, but had the greatest inequalities. In QC, regional HPV vaccination coverage was lower in regions with higher proportions of socially deprived individuals, immigrants, and/or native English speakers (p<0.0001). These inequalities remained stable over time. Regional-level analysis did not reveal inequalities in ON, MB and BC.

CONCLUSION

School-based HPV vaccination programs have resulted in high vaccination coverage in four Canadian provinces. Nonetheless, high overall coverage did not necessarily translate into equality in coverage. Future work is needed to understand underlying causes of inequalities and how this could impact existing inequalities in HPV-related diseases and overall program success.

HPV prevalence and risk of pre-cancer and cancer in regular immigrants in Italy: results from HPV DNA test-based screening pilot programs

ᅟ: Immigrants from low- and medium-income countries have a higher risk of cervical cancer due both to barriers in access to screening and to higher human papillomavirus (HPV) prevalence. In the near future many screening programmes in industrialised countries will replace Pap test with HPV as primary test. In order to plan future interventions, it is essential to understand how the HPV screening performs in immigrant women.

METHODS

We conducted a survey on the main performance indicators from some of the HPV DNA-based pilot programmes in Italy, comparing regular immigrant women, identified as women resident in Italy who were born abroad, with women who were born in Italy. All the programmes applied the same protocol, with HPV as stand-alone test starting for women of 25 or 35 to 64 years of age. Cytology triage is performed for positive women; those ASC-US or more severe are referred directly to colposcopy; negative women are referred to repeat HPV after one year.

RESULTS

Overall, 162,829 women were invited, of whom 22,814 were born abroad. Participation was higher for Italy-born than born abroad (52.2% vs. 43.6%), particularly for women over 45 years. HPV positivity rate was higher in immigrants: 7.8% vs. 6.1%, age-adjusted Relative Risk (age-adj RR) 1.18, 95% confidence interval (95% CI) 1.13-1.22. The proportion of women with positive cytology triage was similar in the two groups (42%). Cervical Intraepithelial Neoplasia (CIN) grade 2 or more severe detection rate was higher for born abroad (age-adj RR 1.65, 95% CI 1.45-1.89). The difference was stronger when considering only CIN3 or more severe (age-adj RR 2.29, 95% CI 1.90-2.75). Both HPV positivity and CIN2 or more severe detection rate had a different age curve in born abroad compared with Italy-born: in the former, the risk was almost flat, while in the latter it declined rapidly with age.

CONCLUSION

Compliance with HPV screening is lower for migrant women, who are affected by higher HPV positivity and CIN3 cancer detection rates.

Illness perceptions and explanatory models of viral hepatitis B & C among immigrants and refugees: a narrative systematic review

BACKGROUND

Hepatitis B and C (HBV, HCV) infections are associated with high morbidity and mortality. Many countries with traditionally low prevalence (such as UK) are now planning interventions (screening, vaccination, and treatment) of high-risk immigrants from countries with high prevalence. This review aimed to synthesise the evidence on immigrants' knowledge of HBV and HCV that might influence the uptake of clinical interventions. The review was also used to inform the design and successful delivery of a randomised controlled trial of targeted screening and treatment.

METHODS

Five databases (PubMed, CINHAL, SOCIOFILE, PsycINFO & Web of Science) were systematically searched, supplemented by reference tracking, searches of selected journals, and of relevant websites. We aimed to identify qualitative and quantitative studies that investigated knowledge of HBV and HCV among immigrants from high endemic areas to low endemic areas. Evidence, extracted according to a conceptual framework of Kleinman's explanatory model, was subjected to narrative synthesis. We adapted the PEN-3 model to categorise and analyse themes, and recommend strategies for interventions to influence help-seeking behaviour.

RESULTS

We identified 51 publications including quantitative (n = 39), qualitative (n = 11), and mixed methods (n = 1) designs. Most of the quantitative studies included small samples and had heterogeneous methods and outcomes. The studies mainly concentrated on hepatitis B and ethnic groups of South East Asian immigrants residing in USA, Canada, and Australia. Many immigrants lacked adequate knowledge of aetiology, symptoms, transmission risk factors, prevention strategies, and treatment, of hepatitis HBV and HCV. Ethnicity, gender, better education, higher income, and English proficiency influenced variations in levels and forms of knowledge.

CONCLUSION

Immigrants are vulnerable to HBV and HCV, and risk life-threatening complications from these infections because of poor knowledge and help-seeking behaviour. Primary studies in this area are extremely diverse and of variable quality precluding meta-analysis. Further research is needed outside North America and Australia.

Immigration, ethnicity, and avoidable mortality in Canada, 1991-2006

OBJECTIVE

Avoidable mortality is a well-recognized, but less studied indicator of the performance of the health system. First, the study seeks to establish whether immigrants overall and selected foreign-born ethnic groups (Western Europeans, South Asians, Chinese, and Filipinos) have an advantage over nonimmigrants in avoidable mortality. Second, it assesses the effect of sociodemographic and socioeconomic factors on any observed differences by duration of residence.

DESIGN

Deaths grouped by cause of death and by behavioral risk factors, namely smoking-related and alcohol-related, were derived from the 1991 Canadian Census Cohort: Mortality and Cancer Follow-up. The analysis estimated age-standardized mortality rates (ASMRs), rate ratios, and rate differences and also fitted hazard regression models for the overall Canadian-born population and for selected foreign-born ethnicities by sex. Predictors were assessed at baseline.

RESULTS

Compared to the Canadian-born persons, foreign-born men and women had lower ASMRs for overall avoidable mortality and also for selected causes of avoidable mortality. The only exception to this overall trend was for ischemic heart disease among South Asian women. Except for the order of prominence, the three leading causes of death for nonimmigrant and immigrant men and women overall were ischemic heart diseases, smoking-related diseases, and neoplasms. A similar pattern was observed among the ethnic groups, except for circulatory heart diseases replacing ischemic heart diseases and smoking-related diseases among Chinese and Filipino women, respectively. In the hazard regression analysis, the risk of avoidable mortality was lower for immigrants overall and selected ethnicities irrespective of the duration in Canada compared to nonimmigrants. These differences persisted even with adjustment for sociodemographic and socioeconomic factors.

CONCLUSION

Immigrants overall and the selected ethnicities enjoy an advantage over nonimmigrants in avoidable mortality. However, for certain causes of death especially ischemic heart disease mortality among South Asian women, immigrants appeared worse-off than nonimmigrants. The results suggest differential access to and use of health services, differences in protective health-related behavior, and the healthy immigrant effect.

Community-based hepatitis B screening: what works?

INTRODUCTION

Chronic hepatitis B (CHB) affects over 350 million people worldwide and can lead to life-threatening complications, including liver failure and hepatocellular cancer (HCC). Modern antiviral therapies could stem the rising tide of hepatitis B-related HCC, provided that individuals and populations at risk can be reliably identified through hepatitis B screening and appropriately linked to care. Opportunistic disease screening cannot deliver population-level outcomes, given the large number of undiagnosed people, but they may be achievable through well-organized and targeted community-based screening interventions.

MATERIAL AND METHODS

This review summarizes the experience with community-based CHB screening programs published in the English-language literature over the last 30 years.

RESULTS

They include experiences from Taiwan, the USA, The Netherlands, New Zealand, and Australia. Despite great variability in program setting and design, successful programs shared common features, including effective community engagement incorporating the target population's cultural values and the ability to provide low-cost or free access to care, including antiviral treatment.

CONCLUSION

While many questions still remain about the best funding mechanisms to ensure program sustainability and what the most effective strategies are to ensure program reach, linkage to care, and access to treatment, the evidence suggests scope for cautious optimism. A number of successful, large-scale initiatives in the USA, Asia-Pacific, and Europe demonstrated the feasibility of community-based interventions in effectively screening large numbers of people with CHB. By providing an effective mechanism for community outreach, scaling up these interventions could deliver population-level outcomes in liver cancer prevention relevant for many countries with a large burden of disease.

Chronic hepatitis B in 2014: great therapeutic progress, large diagnostic deficit

This review analyzes progress and limitations of diagnosis, screening, and therapy of patients with chronic hepatitis B infection. A literature review was carried out by framing the study questions. Vaccination in early childhood has been introduced in most countries and reduces the infection rate. Treatment of chronic hepatitis B can control viral replication in most patients today. It reduces risks for progression and may reverse liver fibrosis. The treatment effect on development of hepatocellular carcinoma is less pronounced when cirrhosis is already present. Despite the success of vaccination and therapy chronic hepatitis B remains a problem since many infected patients do not know of their disease. Although all guidelines recommend screening in high risk groups such as migrants, these suggestions have not been implemented. In addition, the performance of hepatocellular cancer surveillance under real-life conditions is poor. The majority of people with chronic hepatitis B live in resource-constrained settings where effective drugs are not available. Despite the success of vaccination and therapy chronic hepatitis B infection remains a major problem since many patients do not know of their disease. The problems in diagnosis and screening may be overcome by raising awareness, promoting partnerships, and mobilizing resources.

Human Papillomavirus Infection and Cervical Neoplasia among Migrant Women Living in Italy

Human papillomavirus (HPV) infection is highly prevalent in women migrating from countries where cervical screening is not implemented. The variety of HPV genotypes, their prevalence and the association with cervical abnormalities has been investigated by several groups in women moving mainly from Eastern Europe, Africa, and Southern Asia to Italy. All studies are concordant on the elevated rate of HPV infection among immigrants, which is four times higher than that observed among age-matched Italian women. The HPV prevalence among short-term migrants and characterization of viral variants showed that the high prevalence of HPV reflects either individual lifestyle or high prevalence of HPV in the country of origin. The high burden of HPV infection correlates very well with the high incidence of cervical cancer in migrant women. In fact, during the years 2000-2004 the cervical cancer incidence in women from Central and Eastern Europe and living in Central Italy was 38.3 per 100,000, which is statistically significant higher than that of native Italian women (6 per 100,000). In this study, we pooled together the results of three independent studies originally designed to assess the distribution and the prevalence of HPV genotypes among 499 immigrant women living in Southern Italy. A total of 39 mucosal HPV genotypes were identified. The 12 genotypes (HPV16, 18, 31, 33, 35, 39, 45, 51, 52, 56, 58, and 59) classified as carcinogenic to humans (group 1) accounted for >80% of all infections. HPV16 was the most common viral type in all groups with frequency rates ranging from 15.4% in Africa to 51.1% in Eastern and Southern European HPV-positive women. The high prevalence of oncogenic HPVs and cervical cancer risk among migrant women, together with the lower participation in screening programs, demands for an urgent implementation of preventive strategies to increase screening and vaccine coverage and viral monitoring of uncommon HPV genotypes potential spreading in settled population.

Sociodemographic inequalities in sexual activity and cervical cancer screening: implications for the success of human papillomavirus vaccination

BACKGROUND

Papanicolaou smear screening has significantly reduced cervical cancer morbidity and mortality. However, inequalities still persist across different socioeconomic status (SES) groups. These inequalities have been associated with differential participation in screening. However, even with equal participation to screening, some women may still have greater risk of cervical cancer because of sexual behavior. We aim to identify the sociodemographic characteristics of women who reported greater sexual activity and/or screening underuse.

METHODS

We used data from (i) the Canadian Community Health Survey-2005, a population-based survey of 130,000 Canadians, and (ii) a multicenter study including 952 women screened for cervical cancer.

RESULTS

Aboriginals and women with lower SES reported greater sexual activity and lower screening participation, which may produce synergetic effects toward higher cervical cancer risk. Women who did not complete high school and aboriginals were, respectively, 3.6 and 2.5 times more likely to report sexual debut before 15 years old compared with women with university degree and Caucasians. Women who did not complete high school were 2.2 times more likely to have never been screened compared with women with university degree. East and South Asian women were, respectively, 4.3 and 3.1 times more likely to have never been screened than Canadian-born women but reported lower levels of sexual activity and were adherent to screening guidelines when screened at least once.

CONCLUSIONS

The success of human papillomavirus vaccination at reducing cervical cancer and inequalities will depend on achieving high coverage among high-risk subpopulations.

IMPACT

These groups must be monitored closely, and if need be, targeted for additional interventions.

Rates of cancer incidence across terciles of the foreign-born population in Canada from 2001-2006

OBJECTIVES

To address the issue of comparative risk of cancer in Canada's immigrant population, an area-based methodology was applied to examine whether or not estimated cancer incidence rates among individuals living in given areas vary systematically according to the concentration of foreign-born individuals living in the same area. This method provides an alternative, accessible surveillance method in the absence of linked individual-level information to extend the work of others by providing both national and subnational standardized, hence comparable, results to address this issue.

METHODS

Canadian Cancer Registry data (2001 to 2006) and 2006 Census data provided dissemination area information regarding the concentration of the foreign-born population and population estimates for rate denominators. Cancer (all cause and cause-specific) incidence rate ratios (age-standardized and by age/sex) were calculated by foreign-born concentration areas at both national and regional levels.

RESULTS

An inverse gradient was identified between cancer incidence rates and area concentration of foreign-born, with the all-sites cancer rate ranging from a low of 388 per 100,000 among individuals living in areas with a high concentration of foreign-born to a high of 493 per 100,000 among individuals living in areas with a low concentration of foreign-born. This pattern occurred nationally for lung, colorectal, prostate and female breast cancers. However, for liver, nasopharynx, and thyroid cancers, higher cancer rates were observed in areas with a higher versus lower concentration of foreign-born populations.

CONCLUSION

The study findings provide suggestive evidence of decreased cancer risk among foreign-born populations for most cancers except nasopharynx, liver and thyroid for which risks were higher. The results of this study demonstrate the value of ecological-based methods for disease surveillance in the absence of individual-level information on immigrant status in the national cancer registry.

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.

Impact of organised cervical screening on cervical cancer incidence and mortality in migrant women in Australia

Background

Organised cervical screening, introduced in 1991, appears to have reduced rates of cervical cancer incidence and mortality in women in Australia. This study aimed to assess whether cervical cancer rates in migrant women in the state of New South Wales (NSW) showed a similar pattern of change to that in Australian-born women after 1991.

Methods

Data from the NSW Central Cancer Registry were obtained for females 15+ years diagnosed with invasive cervical cancer from 1973 to 2008 (N=11,485). We used joinpoint regression to assess annual percent changes (APC) in cervical cancer incidence and mortality before and after the introduction of organised cervical screening in 1991.

Results

APC in incidence fell more rapidly after than before 1991 (p<0.001) amongst women from seven groups defined by country of birth (including Australia). There was only weak evidence that the magnitude of this incidence change varied by country-of-birth (p=0.088). The change in APC in mortality after 1991, however, was heterogeneous by country of birth (p=0.004). For Australian and UK or Ireland-born women the mortality APC fell more rapidly after 1991 than before (p=0.002 and p=0.001 respectively), as it did for New Zealand, Middle East, North Africa and Asian-born (p≥0.05), but in other European-born and women from the ’Rest of the World’ it appeared to rise (p=0.40 and p=0.013 respectively).

Conclusions

Like Australian-born women, most, but not all, groups of migrant women experienced an increased rate of fall in incidence of cervical cancer following introduction of organised cervical screening in 1991. An apparent rise in mortality in women in a ‘Rest of the World’ category might be explained by a recent rise in migration from countries with high cervical cancer incidence and mortality rates.

Seroprevalence of chronic hepatitis B virus infection and prior immunity in immigrants and refugees: a systematic review and meta-analysis

BACKGROUND

International migrants experience increased mortality from hepatocellular carcinoma compared to host populations, largely due to undetected chronic hepatitis B infection (HBV). We conducted a systematic review of the seroprevalence of chronic HBV and prior immunity in migrants arriving in low HBV prevalence countries to identify those at highest risk in order to guide disease prevention and control strategies.

METHODS AND FINDINGS

Medline, Medline In-Process, EMBASE and the Cochrane Database of Systematic Reviews were searched. Studies that reported HBV surface antigen or surface antibodies in migrants were included. The seroprevalence of chronic HBV and prior immunity were pooled by region of origin and immigrant class, using a random-effects model. A random-effects logistic regression was performed to explore heterogeneity. The number of chronically infected migrants in each immigrant-receiving country was estimated using the pooled HBV seroprevalences and country-specific census data. A total of 110 studies, representing 209,822 immigrants and refugees were included. The overall pooled seroprevalence of infection was 7.2% (95% CI: 6.3%-8.2%) and the seroprevalence of prior immunity was 39.7% (95% CI: 35.7%-43.9%). HBV seroprevalence differed significantly by region of origin. Migrants from East Asia and Sub-Saharan Africa were at highest risk and migrants from Eastern Europe were at an intermediate risk of infection. Region of origin, refugee status and decade of study were independently associated with infection in the adjusted random-effects logistic model. Almost 3.5 million migrants (95% CI: 2.8-4.5 million) are estimated to be chronically infected with HBV.

CONCLUSIONS

The seroprevalence of chronic HBV infection is high in migrants from most world regions, particularly among those from East Asia, Sub-Saharan Africa and Eastern Europe, and more than 50% were found to be susceptible to HBV. Targeted screening and vaccination of international migrants can become an important component of HBV disease control efforts in immigrant-receiving countries.

Association of total energy intake and macronutrient consumption with colorectal cancer risk: results from a large population-based case-control study in Newfoundland and Labrador and Ontario, Canada

Background

Diet is regarded as one of the most important environmental factors associated with colorectal cancer (CRC) risk. A recent report comprehensively concluded that total energy intake does not have a simple relationship with CRC risk, and that the data were inconsistent for carbohydrate, cholesterol and protein. The objective of this study was to identify the associations of CRC risk with dietary intakes of total energy, protein, fat, carbohydrate, fiber, and alcohol using data from a large case-control study conducted in Newfoundland and Labrador (NL) and Ontario (ON), Canada.

Methods

Incident colorectal cancer cases (n = 1760) were identified from population-based cancer registries in the provinces of ON (1997-2000) and NL (1999-2003). Controls (n = 2481) were a random sample of residents in each province, aged 20-74 years. Family history questionnaire (FHQ), personal history questionnaire (PHQ), and food frequency questionnaire (FFQ) were used to collect study data. Logistic regression was used to evaluate the association of intakes of total energy, macronutrients and alcohol with CRC risk.

Results

Total energy intake was associated with higher risk of CRC (OR: 1.56; 95% CI: 1.21-2.01, p-trend = 0.02, 5^th versus 1^st quintile), whereas inverse associations emerged for intakes of protein (OR: 0.85, 95%CI: 0.69-1.00, p-trend = 0.06, 5^th versus 1^st quintile), carbohydrate (OR: 0.81, 95%CI: 0.63-1.00, p-trend = 0.05, 5^th versus 1^st quintile) and total dietary fiber (OR: 0.84, 95% CI:0.67-0.99, p-trend = 0.04, 5^th versus 1^st quintile). Total fat, alcohol, saturated fatty acids, monounsaturated fatty acids, polyunsaturated fatty acids, and cholesterol were not associated with CRC risk.

Conclusion

This study provides further evidence that high energy intake may increase risk of incident CRC, whereas diets high in protein, fiber, and carbohydrate may reduce the risk of the disease.

Increasing incidence in liver cancer in Canada, 1972-2006: Age-period-cohort analysis

BACKGROUND/AIMS

Our study aimed to assess 1) the temporal trends in incidence and mortality of liver cancer and 2) age-period-cohort effects on the incidence in Canada.

METHODS

We analyzed data obtained from the Canadian Cancer Registry Database and Canadian Vital Statistics Death Database. We first examined temporal trends by sex, age group, and birth cohort between 1972 and 2006. Three-year period rates and annual percentage change (APC) were calculated to compare the changes over the study period. We used age-period-cohort modelling to estimate underlying effects on the observed trends in incidence.

RESULTS

The overall age-adjusted incidence rates increased from 2.6 and 1.5 per 100 000 in 1972-74 to 6.5 (APC: 2.9) and 2.2 (APC: 1.2) per 100 000 in 2004-06 among males and females, respectively. The age-adjusted mortality rates increased from 3.3 and 2.0 per 100 000 in 1972-74 to 6.0 (APC: 2.3) and 2.6 (APC: 1.2) per 100 000 in 2004-06 among males and females, respectively. The incidence increased most rapidly in men aged 45-54 years (APC: 4.1) and women aged 65-74 years (APC: 1.7) over the period of study.

CONCLUSIONS

The age-period-cohort analysis suggests that birth-cohort effect is underlying the increase in incidence. While the exact reason for the increased incidence of liver cancer remains unknown, reported increase in HBV and HCV infections, and immigration from high-risk regions of the world may be important factors.

Morbidity and mortality in gynecological cancers among first- and second-generation immigrants in Sweden

We studied the effect of new environment on the risk in and mortality of gynecological cancers in first- and second-generation immigrants in Sweden. We used the nationwide Swedish Family-Cancer Database to calculate standardized incidence/mortality ratios (SIRs/SMRs) of cervical, endometrial and ovarian cancers among immigrants in comparison to the native Swedes. Risk of cervical cancer increased among first-generation immigrants with Danish (SIR = 1.64), Norwegian (1.33), former Yugoslavian (1.21) and East European (1.35) origins, whereas this risk decreased among Finns (0.88) and Asians (SIRs varies from 0.11 in Iranians to 0.54 in East Asians). Risk of endometrial (SIRs varies from 0.28 in Africans to 0.86 in Finns) and ovarian (SIRs varies from 0.23 in Chileans to 0.82 in Finns) cancers decreased in first-generation immigrants. The overall gynecological cancer risk for the second-generation immigrants, independent of the birth region, was almost similar to that obtained for the first generations. The birth region-specific SMRs of gynecological cancers in first- and second-generation immigrants co-varied with the SIRs. Risk of gynecological cancers among the first-generation immigrants is similar to that in their original countries, except for cervical cancer among Africans and endometrial cancer among North Americans and East Europeans. Our findings show that risk and mortality of gynecological cancers observed in the first-generation immigrants remain in the second generation. We conclude that the risk and protective factors of gynecological cancers are preserved upon immigration and through generations, suggesting a role for behavioral factors or familial aggregation in the etiology of these diseases.