Stomach cancer mortality in two large cohorts of migrants from the Former Soviet Union to Israel and Germany: are there implications for prevention?

Awareness and use of psychosocial care among cancer patients and their relatives-a comparison of people with and without a migration background in Germany

PURPOSE

We examined how migration background is associated with awareness and usage of psycho-oncology services.

METHODS

Oncologists in community-based practices and outpatient clinics asked their patients and their relatives to complete a questionnaire. Migrants were purposely over-sampled. The questionnaire was provided in Arabic, English, Farsi, French, German, Hindi, Kurdish, Pashto, Russian, Somali, Turkish, Urdu, and Vietnamese.

RESULTS

From 9 collaborators, 177 participants were enrolled (130 with and 47 without migration background). The existence of outpatient cancer counselling centres was known to 38% of the participants without and 32% with migration background, self-help groups to 32 vs. 12%, and psychotherapy to 43 vs. 25%. Respondents from the Near and Middle East were less likely to know about psychotherapy (odds ratio (OR) 0.1, p = 0.01); those from the Commonwealth of the Independent States or former Yugoslavia were less often informed about self-help groups (OR 0.1, p = 0.06). Migrants retrieved information less frequently from the internet than non-migrants (10 vs. 25%). At least one service had been used by 27% of migrants and 42% of non-migrants (OR 0.5, p = 0.06). After adjusting for gender, age, education, and patient-relative status, there was no evidence for an association between migration background and service use.

CONCLUSIONS

Migrants should be better informed about psychotherapy and self-help groups, in particular the ones coming from the Near or Middle East and the Commonwealth of the Independent States or former Yugoslavia. The under-use of psychosocial services can largely be explained by confounding factors. Therefore, these factors must always be taken into account when analysing the use of psychosocial services in the aforementioned populations.

Socioeconomic deprivation and cancer survival in a metropolitan area: An analysis of cancer registry data from Hamburg, Germany

Background

Few studies have investigated socioeconomic inequalities within cities. Yet, such analyses are particularly important given the increasing international trend to urbanization. Here we investigated area-based socioeconomic inequalities in cancer survival in Hamburg, a port city in the North of Germany (population: 1.84 million people).

Methods

Patients with a diagnosis of colorectal, lung, female breast, and prostate cancer in 2004–2018 (follow-up until 31.12.2018) and registered in the Hamburg cancer registry were included. Area-based socioeconomic deprivation on urban district level was assigned to the patients and grouped in five quintiles. Relative survival in 2014–2018 was calculated using the period approach. Trend analyses between 2004 and 2018 were conducted. Relative excess risks adjusted for age and stage were computed with model-based period analyses.

Findings

For the 73,106 included patients, age-standardized 5-year relative survival in 2014–2018 decreased with increasing deprivation with significant differences between the most and least deprived group of 14·7 (prostate), 10·8 (colorectal), 8·0 (breast), and 2·5 (lung) percent units. Standardization by cancer stage decreased the difference for prostate cancer to 8·5 percent units and for breast cancer to 3·6 percent units but had only a minor effect for colorectal and lung cancer. Similar socioeconomic inequalities were already present in 2004–08.

Interpretation

Strong socioeconomic inequalities in cancer survival were observed in Hamburg, which could be partly explained by differences in the stage distribution. Further research including information on screening participation as well as information on cancer care are important to further understand and finally overcome these inequalities.

Funding

10.13039/501100005972German Cancer Aid.

Hospitalizations Among Chernobyl-Exposed Immigrants to the Negev of Israel, 1992-2017: A Historical Follow-Up Study

On April 26th, 1986 the nuclear reactor at Chernobyl, Ukraine exploded, causing the worst radiation disaster in history. The aim was to estimate hospitalization rates among exposed civilians who later immigrated to Israel. We conducted a historical follow-up study, among persons exposed to Chernobyl (n = 1128) using linked hospitalization records from Soroka University Medical Center (SUMC), compared with immigrants from other areas of the Former Soviet Union (FSU) (n = 11,574), immigrants not from FSU (n = 11,742) and native-born Israelis (n = 8351), matched on age and gender (N = 32,795). Hospitalizations for specific ICD-10 coded diagnostic groups were analyzed by exposure and comparison groups by gender and age at accident. In addition, the rate of hospitalization, and the duration of hospital days and the number of hospitalizations for these selected diagnostic groups was also calculated. Hospitalizations for specific ICD-10 coded diagnostic groups and for any hospitalization in these diagnostic groups in general were analyzed by exposure and comparison groups and by covariates (gender and age at accident). The rate of any hospitalization for the selected diagnostic groups was elevated in the low exposure Chernobyl group (51.1%), which was significantly higher than the immigrant (41.6%) and the Israel-born comparison group (35.1%) (p < .01) but did not differ from either the high exposure group (46.9%) or the FSU comparison group (46.4%), according to the post-hoc tests. The total number of hospitalizations in the low exposure Chernobyl group (2.35) differed from the immigrant (1.73) and Israel comparison group (1.26) (p < .01) but did not differ from the FSU comparison group (1.73) or the high exposure group (2.10). Low exposure women showed higher rates of circulatory hospitalizations (33.8%) compared to immigrants (22.8%) and Israeli born (16.5%), while high exposure women (27.5%) only differed from Israelis (p < .01). Neither exposure group differed from FSU immigrant women on the rate of circulatory hospitalizations. Post-hoc tests showed that among women in the low exposure group, there was a significant difference in rate of hospitalizations for neoplasms (28.6%) compared to the three comparison groups; FSU (18.6%), immigrants (15.7%) and Israel (13.1) (p < .01). Those among the low exposure group who were over the age of 20 at the time of the accident showed the higher rates of circulatory (51.2%) and neoplasm hospitalizations (33.3%), compared to the other immigrant groups (p < .01). When controlling for both age at accident and gender, hospitalizations for neoplasms were higher among Chernobyl-exposed populations (RR = 1.65, RR = 1.77 for high and low-exposure groups, respectively) compared to other FSU immigrants (RR = 1.31) other immigrants (RR = 1.11) and Israeli born (RR = 1.0) after controlling for gender and age at accident. High RRs attributable to Chernobyl exposure were also found for circulatory diseases compared to other immigrants and Israeli born (RRs = 1.50, 1.47 for high and low exposure compared to 1.11. and 1.0, other immigrants and Israeli born, respectively). Endocrine problems and disorders of the eye also showed elevated RR compared to the immigrant comparison groups. Respiratory and mental disorders did not show any consistent association with Chernobyl exposure. The findings support unique Chernobyl morbidity associations only in some diagnostic groups, particularly for low exposure women. General immigration effects on hospitalizations compared to the Israeli born population were found on all diagnostic groups. There is a need to improve the services and medical follow-up for these Chernobyl exposed groups in specific diagnostic groups.

Increased Incidence and Mortality of Gastric Cancer in Immigrant Populations from High to Low Regions of Incidence: A Systematic Review and Meta-Analysis

BACKGROUND & AIMS

Gastric cancer is the leading cause of infection-related cancer death and the third-leading cause of cancer death worldwide. The effect of immigration on gastric cancer risk is not well-defined but might be helpful for screening or surveillance endeavors. We performed a systematic review and meta-analysis to define the risk of gastric cancer in immigrants from high-incidence regions to low-incidence regions (including Western Europe, Australia, Brazil, Canada, Israel, and the United States).

METHODS

We searched MEDLINE and EMBASE databases, from January 1980 to January 2019, for studies that identified immigrants from high-incidence regions of gastric cancer, provided clear definitions of immigrant and reference populations, and provided sufficient data to calculate gastric cancer incidence and gastric cancer-related mortality. We performed meta-analyses of standardized incidence ratios (SIR) for first-generation immigrants from high- to low-incidence regions, stratified by immigrant generation, sex, and anatomic and histologic subtype, when data were available.

RESULTS

We identified 38 cohort studies that met our inclusion criteria. All 13 studies of 21 distinct populations reported significantly increased SIRs for gastric cancer in first-generation foreign-born immigrants (men SIR range, 1.24-4.50 and women SIR range, 1.27-5.05). The pooled SIR for immigrants with all types of gastric cancer was 1.66 (95% CI, 1.52-1.80) for men and 1.83 (95% CI, 1.69-1.98) for women. Nine studies from 2 high-incidence populations (the former Soviet Union and Japan) reported an increased gastric cancer standardized mortality ratio in first-generation immigrants who migrated to regions of low incidence (former Soviet Union immigrants, 1.44-1.91 for men and 1.40-2.56 for women).

CONCLUSIONS

Immigrants from regions with a high incidence of gastric cancer to regions of low incidence maintain a higher risk of gastric cancer and related mortality, based on a comprehensive systematic review and meta-analysis. Assessment of immigrant generation along with other risk factors might help identify high-risk populations for prevention and therapeutic interventions.

[Health status of people with a migrant background and impact of socio-economic factors: First results of the German Health Interview and Examination Survey for Adults (DEGS1)]

People with a migrant background (PMB) have specific health-related risk factors and resources compared to the non-migrant population (NMP). The analysis focuses on the relationship between migrant background and health and health-related behavior. Moreover, the study analyses whether socio-economic status (SES) contributes to the explanation of differences between PMB and the NMP. The research is based on the German Health Interview and Examination Survey for Adults (DEGS1) (2008-2012, n = 8151). The population for cross-sectional analyses contains 1107 PMB (weighted 19.8 %). The research question is addressed on the basis of nine exemplary health outcomes. All analyses are gender specific and make a distinction between first and second generation PMB. Logistic regression is calculated adjusting for age and SES. The results reveal clear gender-specific patterns: For women, differences are statistically significant mainly for first generation PMB. Compared to the NMP their self-assessed health status is lower, they are less physically active, consume less alcohol, feel less informed about cancer screening programs and make less use of preventive health services. However, daily smoking is more prevalent in second generation women. For men, differences are statistically significant for first and second generation PMB. Men with a migrant background show more symptoms of depression, consume less alcohol and feel less informed about cancer screening programs. After adjusting for SES the impact of migrant background on health status and health-related behavior largely remains stable. The study shows that the DEGS1 data offers valuable results and new insights into the health status of people with a migrant background. The use of this data for further research requires a differentiated approach to the concept of migrant background and a careful interpretation of results.

Histologic types of gastric cancer among migrants from the former Soviet Union and the general population in Germany: what kind of prevention do we need?

OBJECTIVE

The incidence of gastric cancer (GC) is high among migrants from Eastern Europe and Asia, but a detailed picture of disease characteristics is missing. Our study examined the incidence of histologic types among resettlers from the former Soviet Union and the general population in Germany to draw conclusions on risk factors and possible prevention strategies.

METHODS

Between 1990 and 2009, all GC diagnoses among a cohort of 18 619 resettlers residing in the Saarland were identified in the Saarland Cancer Registry database. Age-standardized incidence rates (ASRs) of the entire Saarland population and standardized incidence ratios (SIRs) of resettlers compared with the Saarland population were calculated for types according to Laurén. In addition, ASRs and SIRs were modeled using Poisson's regression to investigate time trends.

RESULTS

The ASR of intestinal GC in the Saarland population decreased over time, whereas the ASR of diffuse GC remained unchanged. Resettlers' incidence of intestinal GC was elevated among men [SIR: 3.04, 95% confidence interval (CI): 2.05-4.50] and women (SIR: 2.78, 95% CI: 1.61-4.79), whereas diffuse GC was elevated only among women (SIR: 1.98, 95% CI: 1.07-3.69). No time trends for SIRs could be observed in regression analysis.

CONCLUSION

Different trends of diffuse GC incidence in Germany and the USA underline the importance of environmental risk factors. The continuously elevated risk of GC among male resettlers is probably associated with risk factors affecting exclusively the intestinal type such as a low intake of fruit and vegetables and heavy alcohol consumption. Future prevention programs for resettlers should include dietary measures.

Clinical epidemiology of gastric cancer

Gastric cancer is the second leading cause of cancer-related mortality and the fourth most common cancer globally. There are, however, distinct differences in incidence rates in different geographic regions. While the incidence rate of gastric cancer has been falling, that of gastric cardia cancers is reportedly on the rise in some regions. Helicobacter pylori (H. pylori) infection is a major risk factor of non-cardia gastric cancer, and data has emerged concerning the role of H. pylori eradication for primary prevention of gastric cancer. Dietary, lifestyle and metabolic factors have also been implicated. Although addressing these other factors may contribute to health, the actual impact in terms of cancer prevention is unclear. Once irreversible histological changes have occurred, endoscopic surveillance would be necessary. A molecular classification system offers hope for molecularly tailored, personalised therapies for gastric cancer, which may improve the prognosis for patients.

Geographical distribution of the incidence of gastric cancer in Bhutan

AIM: To estimate the prevalence of gastric cancer (GC) in a cohort of patients diagnosed with GC and to compare it with patients diagnosed with all other types of gastro-intestinal (GI) cancer during the same period.

METHODS: Between 2008 and 2013, five-year period, the medical records of all GI cancer patients who underwent medical care and confirm diagnosis of cancer were reviewed at the National Referral Hospital, Thimphu which is the only hospital in the country where surgical and cancer diagnosis can be made. Demographic information, type of cancer, and the year of diagnosis were collected.

RESULTS: There were a total of 767 GI related cancer records reviewed during the study period of which 354 (46%) patients were diagnosed with GC. There were 413 patients with other GI cancer including; esophagus, colon, liver, rectum, pancreas, gall bladder, cholangio-carcinoma and other GI tract cancers. The GC incidence rate is approximately 0.9/10000 per year (367 cases/5 years per 800000 people). The geographic distribution of GC was the lowest in the south region of Bhutan 0.3/10000 per year compared to the central region 1.4/10000 per year, Eastern region 1.2/10000 per year, and the Western region 1.1/10000 per year. Moreover, GC in the South part was significantly lower than the other GI cancer in the same region (8% vs 15%; OR = 1.8, 95%CI: 1.3-3.1, P = 0.05). Among GC patients, 38% were under the age of 60 years, mean age at diagnosis was 62.3 (± 12.1) years with male-to-female ratio 1:0.5. The mean age among patients with all other type GI cancer was 60 years (± 13.2) and male-to-female ratio of 1:0.7. At time of diagnosis of GC, 342 (93%) were at stage 3 and 4 of and by the year 2013; 80 (23%) GC patients died compared to 31% death among patients with the all other GI cancer (P = 0.08).

CONCLUSION: The incidence rate of GC in Bhutan is twice as high in the United States but is likely an underestimate rate because of unreported and undiagnosed cases in the villages. The high incidence of GC in Bhutan could be attributed to the high prevalence of Helicobacter pylori infection that we previously reported. The lowest incidence of GC in Southern part of the country could be due to the difference in the ethnicity as most of its population is of Indian and Nepal origin. Our current study emphasizes on the importance for developing surveillance and prevention strategies for GC in Bhutan.

Remigration of migrants with severe disease: myth or reality?--a register-based cohort study

BACKGROUND

'Remigration bias' is often referred to when explaining low mortality outcomes among migrants compared with local-born. The hypothesis suggests that severely ill migrants tend to return to their country of origin, but it has hitherto not been tested in a large-scale epidemiological study. Consequently, we studied whether migrants with severe disease were more likely to emigrate compared with migrants without severe disease.

METHODS

A historic prospective cohort study was conducted based on all adult refugees and family reunification immigrants (n = 114,331) who obtained residence permission in Denmark between 1 January 1993 and 31 December 2010. Migrants with severe disease were identified through the Danish National Patient Register. Emigrations during follow-up (1 January 1993 to 31 December 2011) were identified using the Danish Civil Registration System. Hazard ratios were calculated for emigration among migrants with different levels of disease severity, adjusting for sex, age and income.

RESULTS

Results showed progressively fewer emigrations with increasing disease severity. Migrants with low (HR = 0.92; 95% CI: 0.80-1.06), moderate (HR = 0.84; 95% CI: 0.67-1.06) and high (HR = 0.70; 95% CI: 0.55-0.90) disease severity had fewer emigrations to 'country of origin' compared with migrants without disease. For emigration to 'any country', results likewise showed fewer emigrations among migrants with low (HR = 0.86; 95% CI: 0.78-0.95), moderate (HR = 0.73; 95% CI: 0.62-0.87) and high (HR = 0.64; 95% CI: 0.53-0.76) disease severity. This tendency was also observed by nationality and migrant status. On the disease-specific level, no uniform tendencies in emigration patterns were identified.

CONCLUSION

The results do not generally support the hypothesis of 'remigration bias' but rather suggest the opposite. Accordingly, remigration bias does not appear to explain lower mortality of migrants.

Cancer mortality by country of birth, sex, and socioeconomic position in Sweden, 1961-2009

In 2010, cancer deaths accounted for more than 15% of all deaths worldwide, and this fraction is estimated to rise in the coming years. Increased cancer mortality has been observed in immigrant populations, but a comprehensive analysis by country of birth has not been conducted. We followed all individuals living in Sweden between 1961 and 2009 (7,109,327 men and 6,958,714 women), and calculated crude cancer mortality rates and age-standardized rates (ASRs) using the world population for standardization. We observed a downward trend in all-site ASRs over the past two decades in men regardless of country of birth but no such trend was found in women. All-site cancer mortality increased with decreasing levels of education regardless of sex and country of birth (p for trend <0.001). We also compared cancer mortality rates among foreign-born (13.9%) and Sweden-born (86.1%) individuals and determined the effect of education level and sex estimated by mortality rate ratios (MRRs) using multivariable Poisson regression. All-site cancer mortality was slightly higher among foreign-born than Sweden-born men (MRR = 1.05, 95% confidence interval 1.04-1.07), but similar mortality risks was found among foreign-born and Sweden-born women. Men born in Angola, Laos, and Cambodia had the highest cancer mortality risk. Women born in all countries except Iceland, Denmark, and Mexico had a similar or smaller risk than women born in Sweden. Cancer-specific mortality analysis showed an increased risk for cervical and lung cancer in both sexes but a decreased risk for colon, breast, and prostate cancer mortality among foreign-born compared with Sweden-born individuals. Further studies are required to fully understand the causes of the observed inequalities in mortality across levels of education and countries of birth.

Cancer incidence in ethnic German migrants from the Former Soviet Union in comparison to the host population

AIM

To investigate cancer incidence patterns among ethnic German migrants (Aussiedler) from the Former Soviet Union, a large migrant group in Germany, in comparison to autochthonous Saarland population over a 20 year observation period.

METHODS

Data were obtained from a cohort of Aussiedler residing in the federal state of Saarland (n=18,619). Cancer incidence and vital status were ascertained through record linkage with the Saarland Cancer Registry and local population registries.

RESULTS

During the follow up period from 1990 to 2009 we observed 638 incident diagnoses of malignant neoplasms (except non-melanoma skin cancer). The overall standardized incidence ratio (SIR) was 0.98 (95% confidence interval 0.92, 1.04). However, site-specific SIRs revealed great variation. Stomach cancer incidence was significantly higher among Aussiedler. Lung cancer was elevated for males, but lower among females. Additionally, diagnoses for colorectal cancer among males were significantly lower. Age-standardized rates (ASRs) over time show not all cancer rates of Aussiedler attenuate as expected to Saarland rates. For example, lung and prostate cancer incidence rates show increasing disparity from Saarland rates and female breast cancer incidence develops in parallel. Furthermore, ASR for overall cancer incidence of Aussiedler shows a yearly decrease (p=0.06) whereas Saarland rates remain stable.

DISCUSSION

Aussiedler incidence rates reflect incidence pattern observed in their countries of origin.

Prostate cancer in Germany among migrants from the Former Soviet Union

Background

In Germany, prostate cancer is the leading cause of cancer and the third leading cause of death from cancer in males. We investigate prostate cancer in Gernmany among migrants from the Former Soviet Union (FSU) and compare them to indigenous German population with regard to prostate cancer incidence, mortality and longitudinal effects.

Methods

Data were obtained from two migrant cohorts residing in the federal states of North Rhine Westphalia (n=34,393) and Saarland (n=18,619). Vital status was ascertained through local population registries. Causes of death were obtained from the federal statistical office or from local health authorities. Cancer incidence of the Saarland cohort was derived from the Saarland Cancer Registry using record linkage.

Results

From 1990 to 2005 we observed 3360 deaths of which 28 were due to prostate cancer. In the Saarland cohort 35 men were diagnosed with prostate cancer during the respective period. Migrants had lower prostate cancer incidence (SIR 0.74 (95% CI: 0.52–1.03)) and mortality (SMR 0.57 (95% CI: 0.38–0.83)) compared to the German population. Multivariate analysis showed a strong age effect on incidence meaning young migrants (below age 60) were diagnosed significantly more often with prostate cancer compared to Germans of the same age. However, mortality did not show any effects.

Discussion

Lower prostate cancer mortality and incidence among migrants may reflect an ongoing situation in the FSU. Additionally, longitudinal analysis did not reveal convergence of migrant prostate cancer to German rates as expected from lifestyle driven cancer sites. Therefore, our results support the hypothesis of a genetic effect on prostate cancer risk.

Dietary folate protects against azoxymethane-induced aberrant crypt foci development and oxidative stress in rat colon

Azoxymethane (AOM) induces cancer and oxidative stress in rat colon. This study tested the hypothesis that dietary folate supplementation protects against AOM-induced oxidative stress and reduces aberrant crypt foci (ACF) development in rat colon. Fifty-four weanling male albino rats, with an average body weight of 50 ± 5 g, were randomly divided into three groups – A, B and C (18 rats per group) – and fed 2, 8 or 40 mg of folic acid per kg of supplemented diets, respectively, throughout the eight weeks' experimental period. The animals were supplied with diet and water ad libitum for four weeks and they reached an average body weight of 100 g. Thereafter each group was then further randomly subdivided into three subgroups (six rats per subgroup): control, vehicle and AOM-injected groups. The control group did not receive any treatment (neither AOM injection nor saline), the rats in the vehicle group were given 1 mL intraperitoneal injection of saline once a week for two weeks and the rats in the AOM-injected group were given two intraperitoneal injections of AOM dissolved in saline once a week for two weeks totaling 30 mg/kg body weight. After the last AOM injection, animals were continuously fed ad libitum their specified diet for two weeks of last AOM injection, all rats were sacrificed, and colon tissues were collected and used for ACF enumeration and measurements of glutathione (GSH) and total antioxidant capacity (TAC). The results revealed that AOM-injected rats showed lower levels of GSH and TAC as compared with control and vehicle groups. Folic acid-supplemented diets suppressed the AOM-induced ACF and GSH depletion in a dose-dependent manner and augmented the TAC. It was concluded that folic acid supplementation protects against the AOM-induced ACF formation by suppressing the AOM-induced GSH depletion in rat colon cells.

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.

Ethnic differences in cancer incidence in Estonia: two cross-sectional unlinked census-based cancer incidence analyses

BACKGROUND

Estonian and Russian ethnic groups in Estonia differ from one another in several aspects, such as historic and socio-economic background, language and culture. The aim of the current study was to examine ethnic differences in cancer incidence in Estonia, and to compare the situation before and after the profound political and economical changes in the early 1990s.

METHODS

Two cross-sectional unlinked census-based cancer incidence analyses were performed. Cancer incidence data were obtained from the Estonian Cancer Registry. Population denominators came from the population censuses of 1989 and 2000. Standardized cancer incidence rates were calculated for men and women for the aggregate periods 1988-1990 and 1999-2000. Differences in cancer incidence between Estonians and Russians in 1989 and 2000 were estimated for both sexes, using standardized rate ratios with 95% confidence intervals.

RESULTS

In 1988-1990, the total cancer incidence in Russian men was higher than that in Estonian men (SRR = 1.26, 95%CI = 1.19-1.34). In 1999-2000, the total cancer incidence in men showed only slightly higher estimates in Russians than in Estonians (SRR = 1.06, 95%CI = 0.99-1.32). Cancers of stomach, colon and lung had persisting higher values in Russian men in 1999-2000. In women, the differences were smaller than in men, and the total cancer incidence showed no differences relating to neither of the time periods studied. With regard to specific sites, excess of stomach cancer incidence was seen in Russian women (SRR = 1.45, 95%CI = 1.15-1.81). The ethnic differences in general decreased between the two time periods studied.

CONCLUSION

Some of the differences in cancer rates between the Estonians and Russians in Estonia are likely to be attributable to the variation in exposure to specific etiologic factors that are causedby differences in lifestyle and habits, such as hygiene, smoking and drinking. Further research with a view to understanding these ethnic differences in cancer incidence is warranted.