Cancer incidence, trends, and survival among immigrants to Sweden

Abstract

This review aimed at covering cancer risk trends by site and histology in first-generation and second-generation immigrants in Sweden compared with natives. In addition, we reviewed data on cancer survival in immigrants to explore factors explaining cancer survival in the entire population. The Swedish Family-Cancer Database was used to calculate standardized incidence ratios and hazard ratios (HRs) of death from cancer in 77,360 and 993,824 cases among first-generation, and 4356 and 263,485 cases among second-generation immigrants and Swedes, respectively. Ordinal logistic regression analyses were used to calculate odds ratio. To obtain the maximum number of cases, we classified the immigrants according to geographical setting, population, and/or cancer risk. Compared with native Swedes, the highest risk of cancer was observed for nasopharyngeal carcinoma in Southeast Asian men (standardized incidence ratio=35.6) and women (24.6), for hypopharyngeal carcinoma in Indian men (5.4), for squamous-cell carcinoma of the esophagus in Iranian women (3.8), for cardia of the stomach in East Asian women (4.2), for signet-ring cell carcinoma of the stomach in Southeast Asian women (6.7), for the liver in East Asian men (6.8), for the gall bladder in Indian women (3.8), for the pancreas in North African men (2.2), for large cell carcinoma of the lung in former Yugoslavian men (4.2), for pleural mesothelioma in Turkish women (23.8), for the cervix in Danes (1.6), for seminoma in Chileans (2.1), for transitional-cell carcinoma of the bladder in Asian Arab men (2.3), for meningioma in former Yugoslavians (1.3), and for papillary carcinoma of the thyroid in East and Southeast Asian men (3.6). No immigrant groups had an increased risk of breast, uterus, ovary, and prostate cancers or nervous system tumors. The HRs for all breast cancers were between 1.0 in low-risk Europeans and 1.2 in lowest-risk non-Europeans. Low-risk non-Europeans had an HR of 2.9 for lobular carcinoma. Low-risk non-Europeans were diagnosed in a higher T-class (odds ratio=1.9) than Swedes. The HRs for prostate cancer were 0.6 in Turks, Middle Easterners, Asians, and Chileans. In conclusion, environmental and behavioral factors, early-childhood exposures, and infections may play a major role in the risk of esophageal, stomach, liver, nasopharyngeal and hypopharyngeal cancers, malignant pleural mesothelioma, breast, gynecological, testicular, urinary bladder, and thyroid cancers. Pancreatic cancer and nervous system tumors may have a major genetic component in the etiology. The ethnic differences in the risk of breast cancer by histology had no major influence on survival. Middle Easterners, Asians, and Chileans, with the lowest risk of prostate cancer, also had the most favorable survival, suggesting a biological mechanism for this finding.

Comparison of cancer stage distribution in the immigrant and host populations of Norway, 1990–2014

“…These findings are consistent with previous results from South East England . Swedish studies on prostate and lung cancer with data from 2002–2008 and 2003–2008, respectively, showed no difference in stage at diagnosis between immigrants and the general population . A Danish study included several cancer sites in women and reported that immigrants had a slightly higher risk of being diagnosed at a more advanced stage than the host population .…”

Differences in cancer survival between immigrants in Norway and the host population

“…[11][12][13][14][15][16] The better lung cancer survival in non-Western immigrants than Norwegians is of particular interest, and not readily explained by residence time, stage at diagnosis, socioeconomic factors or comorbidity. We did not find differences in cancer survival between Western immigrants and Norwegians, while non-Western immigrants, with some exceptions, had similar or better survival.…”

“…[11][12][13][14][15][16] A few Nordic studies have reported worse survival in immigrants with breast cancer and melanoma relative to the host populations. [11][12][13][14][15][16] A few Nordic studies have reported worse survival in immigrants with breast cancer and melanoma relative to the host populations.…”

Geographical Variation and Factors Associated with Non-Small Cell Lung Cancer in Manitoba

“…Immigrant populations in economically developed nations appear to be at lower risk of cancer overall but at higher risk for cancers caused by microbial infections, such as liver and cervical cancers [43, 44]. In Canada, an inverse correlation of cancer incidence rates and the area concentration rate of foreign-born residents has been demonstrated.…”