Age- and time-dependent changes in cancer incidence among immigrants to Sweden: colorectal, lung, breast and prostate cancers.
ABSTRACT To examine the role of gender, age at immigration and length of stay on incidence trends of common cancers, we studied risk of colorectal, lung, breast and prostate cancers in immigrants to Sweden from 1958 to 2008. The nationwide Swedish Family-Cancer Database was used to calculate standardized incidence ratios for common cancers among immigrants compared to Swedes. Immigrants were classified into "high-risk" countries when their risk was increased, into "low-risk" when their risk was decreased and into "other" when their risk was nonsignificant. Among those who immigrated at younger age (<30 years), we found an increasing trend for colorectal cancer risk in low-risk men and high-risk women. Among those who immigrated at older age (≥ 30 years), a decreasing lung cancer risk in high-risk men and an increasing breast cancer risk in low-risk women were observed. The increasing trend of prostate cancer risk was independent of age at immigration. The risk trends for "other" immigrants were between the risks of low- and high-risk countries. The gender-specific shifts in cancer risks in immigrants toward the risk in natives indicate a major role of sex, age at immigration and environmental exposures in colorectal and lung cancers risks. In contrast, the unchanged trend of breast cancer among those who immigrated at younger ages and an increasing trend for those who migrated at older ages may suggest a limited effect for environmental exposures, especially at younger age. Our study points out a role of age at immigration on the risk trend of cancer.
- SourceAvailable from: Michael G Marmot[show abstract] [hide abstract]
ABSTRACT: Risk of cancer mortality from 1973 to 1985 in persons born in the Indian subcontinent who migrated to England and Wales was analysed by ethnicity, and compared with cancer mortality in the England and Wales native population, using data from England and Wales death certificates. There were substantial highly significant raised risks in Indian ethnic migrants for cancers of the mouth and pharynx, gall bladder, and liver in each sex, larynx and thyroid in males, and oesophagus in females. There were also substantial raised risks in these migrants of each sex for non-Hodgkin's lymphoma and myeloma. For the mouth and pharynx, and liver in each sex, and gall bladder in females, there were also raised risks of lesser magnitude in British ethnic migrants. For colon and rectal cancer and cutaneous melanoma in each sex, ovarian cancer in women and bladder cancer in men, there were appreciable significantly reduced risks in the Indian ethnic migrants not shared by those of British ethnicity. Appreciable raised risks in British ethnic migrants not shared by those of Indian ethnicity occurred for nasopharyngeal cancer in males, soft tissue malignancy in both sexes and non-melanoma skin cancer in males. In migrants of both ethnicities there were appreciable significantly raised risks in each sex for leukaemia and decreased risks in each sex for gastric cancer, for lung cancer except in females of British ethnicity and in males for testicular cancer. The results suggest the need for public health measures to combat the high risks of oral and pharyngeal cancers and liver cancer in the Indian ethnic immigrant population of England and Wales, by prevention of betel quid chewing and hepatitis transmission respectively. The data also imply that early exposures or early acquired behaviours in India, or exposures during migration, may increase the risk of leukaemia and reduce the risks of gastric and testicular cancers in the migrants irrespective of their ethnicity. Aetiological studies would be worthwhile to investigate the reasons for the sizeable decreased risk of colon and rectal cancer and increased risk of gall bladder cancer in each sex and the increased risk of thyroid and laryngeal cancer in males and oesophageal cancer in females of Indian ethnicity but not of British ethnicity who have migrated from the Indian subcontinent.British Journal of Cancer 12/1995; 72(5):1312-9. · 5.08 Impact Factor
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ABSTRACT: We used the nationwide Swedish Family-Cancer Database to analyse cancer risks in 613,000 adult immigrants to Sweden. All the immigrants had become parents in Sweden and their median age at immigration was 24 years for men and 22 years for women. We calculated standardized incidence ratios (SIRs) and 95% confidence intervals (CIs) for 18 cancer sites using native Swedes as a reference. Data were also available from compatriot marriages. All cancer was decreased by 5% and 8% for immigrant men and women, respectively. However, most of the male increase was due to lung cancer for which male immigrants showed a 41% excess. Among individual cancer sites and immigrant countries, 110 comparisons were significant, 62 showing protection and 48 an increased risk. Most of the differences between the rates in immigrants and Swedes could be ascribed to the variation of cancer incidence in the indigenous populations. Some high immigrant SIRs were 5.05 (n = 6, 95% CI 1.82-11.06) for stomach cancer in Rumanian women and 2.41 (41, 1.73-3.27) for lung cancer in Dutch men. At some sites, such as testis, prostate, skin (melanoma), kidney, cervix and nervous system, the SIRs for immigrants were decreased; in some groups of immigrants SIRs were about 0.20. The highest rates for testicular cancer were noted for Danes and Chileans. Women from Yugoslavia and Turkey had an excess of thyroid tumours. All immigrant groups showed breast, endometrial and ovarian cancers at or below the Swedish level but the differences were no more than 2-fold.International Journal of Cancer 06/2002; 99(2):218-28. · 6.20 Impact Factor
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ABSTRACT: We used the nationwide Swedish Family-Cancer Database to analyze cancer risks in Sweden-born descendants of immigrants from European and North American countries. Our study included close to 600,000 0-66-year-old descendants of an immigrant father or mother. We calculated standardized incidence ratios (SIRs) and 95% confidence intervals (CIs) for 17 cancer sites using native Swedes as a reference. All cancer was marginally below the Swedish incidence in offspring of immigrant origin. Decreased SIRs were observed for breast cancer among Norwegian descendants, melanoma among descendants of Hungarian fathers and ovarian and bladder cancer among descendents of Finnish mothers, all consistent with the difference in cancer incidence between Swedes and the indigenous populations. Cervical cancer was increased in daughters of Danish men, whereas thyroid cancer and non-Hodgkin's lymphoma were in excess in offspring of parents of Yugoslav and Asian descent. Even these results agreed with the high incidence rates in parents compared to Swedes, except that for non-Hodgkin's lymphoma other explanations are needed; these may be related to immune malfunction. Comparison of the results between the first- and the second-generation immigrants suggest that the first 2 decades of life are important in setting the pattern for cancer development in subsequent life. Birth in Sweden sets the Swedish pattern for cancer incidence, irrespective of the nationality of descent, while entering Sweden in the 20s is already too late to influence the environmentally imprinted program for the cancer destiny.International Journal of Cancer 06/2002; 99(2):229-37. · 6.20 Impact Factor