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Numerous studies have reported lower overall cancer mortality rates among immigrants compared to native populations. However, limited information exists regarding cancer mortality among immigrants based on specific birth countries and cancer types. We used population-based registries and followed 10 million individuals aged 20 years or older in Sweden between 1992 and 2016. The Cox proportional hazard model was used to explore the disparities in cancer mortality by country of birth and cancer type, stratified by gender. Age-standardized mortality rates were also computed using the world standard population. Hazard ratio (HR) of all-site cancer was slightly lower among immigrants (males: HR m  = 0.97: 95% confidence interval: 0.95, 0.98; females: HR f  = 0.93: 0.91, 0.94) than Swedish-born population. However, the immigrants showed higher mortality for infection-related cancers, including liver (HR f  = 1.10: 1.01, 1.19; HR m  = 1.10: 1.02, 1.17), stomach (HR f  = 1.39: 1.31, 1.49; HR m  = 1.33: 1.26, 1.41) cancers, and tobacco-related cancers, including lung (HR m  = 1.44: 1.40, 1.49), and laryngeal cancers (HR m  = 1.47: 1.24, 1.75). The HR of mesothelioma was also significantly higher in immigrants (HR f  = 1.44: 1.10, 1.90). Mortality from lung cancer was specifically higher in men from Nordic (HR m  = 1.41: 1.27, 1.55) and non-Nordic Europe (HR m  = 1.49: 1.43, 1.55) countries and lower in Asian (HR m  = 0.78: 0.66, 0.93) and South American men (HR m  = 0.70: 0.57, 0.87). In conclusion, there are large variations in cancer mortality by country of birth, and cancer type and require regular surveillance. Our detailed analyses lead to some novel findings such as excess mortality rate of mesothelioma and laryngeal cancers in Immigrants in Sweden. A targeted cancer prevention program among immigrants in Sweden is needed., (© 2024 The Author(s). Cancer Medicine published by John Wiley & Sons Ltd.)

Introduction: To investigate the occurrence of previous cancer diagnoses in women suffering from premature ovarian insufficiency (POI) and compare it with the general population, shedding light on the association between cancer, cancer treatments, and POI., Material and Methods: We conducted a nationwide case-control study based on registry data from various sources, including the Social Insurance Institution, Finnish Population Information System, and Finnish Cancer Registry spanning from 1953 to 2018. Our participants comprised all women in Finland who, between 1988 and 2017, received hormone replacement therapy reimbursement for ovarian insufficiency before the age of 40 years (n = 5221). Controls, matched in terms of age and municipality of residence, were selected from the Finnish Population Information System (n = 20 822). Our main exposure variable was a history of cancer diagnosis preceding the diagnosis of POI. We analyzed odds ratios (OR) to compare the prevalence of previous cancers in women with POI with that in controls, stratifying results based on cancer type, age at cancer diagnosis, and the time interval between cancer diagnosis and POI. We also assessed changes in OR for previous cancer diagnoses over the follow-up period., Results: Out of the women diagnosed with POI, 21.9% had previously been diagnosed with cancer, resulting in an elevated OR of 36.5 (95% confidence interval [CI] 30.9 to 43.3) compared with 0.8% of the controls. The risk of developing POI was most pronounced during the first 2 years following a cancer diagnosis, with an OR of 103 (95% CI 74.1 to 144). Importantly, this risk remained elevated even when the time interval between cancer and POI exceeded 10 years, with an OR of 5.40 (95% CI 3.54 to 8.23)., Conclusions: This study reveals that 21.9% of women with POI have a history of cancer, making the prevalence of cancer among these women 27.5 times higher than age-matched controls in the Finnish population. The risk of developing POI is most substantial in the first 2 years following a cancer diagnosis. These findings underscore the role of cancer treatments as an etiological factor for POI and emphasize the importance of recognizing the risk of POI in cancer survivors for early diagnosis and intervention., (© 2024 The Authors. Acta Obstetricia et Gynecologica Scandinavica published by John Wiley & Sons Ltd on behalf of Nordic Federation of Societies of Obstetrics and Gynecology (NFOG).)

Purpose: Evaluate the occupational variation in incidence of oropharyngeal cancer (OPC)., Methods: We calculated standardized incidence ratios (SIRs) of OPC in occupational categories in the Nordic countries relative to the entire national populations. The data covered 6155 OPC cases., Results: Among men high risk of OPC was observed, among else, in waiters (SIR 6.28, 95% CI 4.68-8.26), beverage workers (SIR 3.00, 95% CI 1.72-4.88), and artistic workers (SIR 2.97, 95% CI 2.31-3.76). Among women high risk of OPC was observed in waiters (SIR 2.02, 95% CI 1.41-2.81) and packers (SIR 1.73, 95% CI 1.07-2.64). The lowest SIRs were observed in female gardeners (SIR 0.27, 95% CI 0.12-0.51) and male farmers (SIR 0.30, 95% CI 0.25-0.35)., Conclusion: The 20-fold variation in incidence of OPC between occupations needs further investigation in studies with detailed information on occupational and non-occupational risk factors., (© 2023. The Author(s).)

Introduction: Professional visual artists constitute a heterogeneous vocational group, including, but not limited to painters, photographers, textile artists, and sculptors who may face exposure to workplace hazardous substances and lifestyle factors that may contribute to the development of selected cancers. The objective of this registry-based cohort study was to assess the cancer incidence among Nordic visual artists., Materials and Methods: This study is based on data from the Nordic Occupational Cancer (NOCCA) project that combines census data of 15 million people from all Nordic countries and cancer registries from 1961 to 2005. For the present study we selected a cohort of visual artists from Finland, Iceland, Norway, and Sweden. Standardized incidence ratio (SIR) analyses were conducted with the cancer incidence rates for the entire national study populations used as reference rates., Results: In male visual artists, there were statistically significant excesses in cancers of the tongue (SIR 2.91, 95% confidence interval 1.74-4.55), oral cavity (2.09, 1.26-3.27), pharynx (2.18, 1.45--3.15), testis (1.91, 1.11-3.05), renal pelvis (2.48, 1.42-4.03) and bladder (1.33, 1.14-1.55). The risk was significantly decreased for cancers of the lip (0.45, 0.18-0.93) and stomach (0.65, 0.50-0.84). In female visual artists, the only significantly increased risk was observed for breast cancer (1.29, 1.13-1.48) and the only significantly decreased risk for stomach cancer (0.43, 0.17-0.88). The incidence of lung cancer was close to the population average in both sexes., Conclusions: The non-elevated incidence of lung cancer suggests a similar prevalence of smoking between visual artists and the general population, while the elevated risk of cancers of mouth and pharynx among male visual artists is suggestive of more widespread alcohol drinking. The excess risk of urogenital cancers might be associated with exposure to solvents.

Introduction: While certain occupations, such as agriculture and fishery, have been associated with an increased risk of lip cancer, the occupational risk profile of lip cancer and its change over time remain poorly known. This study aims to evaluate the incidence of lip cancer across different occupations in the Nordic countries., Methods: The Nordic Occupational Cancer Study (NOCCA) covers 14.9 million people and includes 45 years of cancer incidence data, from 1961 to 2005, linked to occupational categories for all the five Nordic populations. Standardized incidence ratios (SIRs) with 95% confidence intervals (CIs) were used to quantify the risk of lip cancer across occupational categories relative to the entire national populations., Results: There were a total of 14,477 male and 3008 female lip cancer patients identified during follow up. The highest SIRs were observed among male fishermen (SIR 2.26, 95% CI: 2.04-2.50), gardeners (SIR 1.60, 95% CI: 1.48-1.72), and farmers (SIR 1.60, 95% CI: 1.55-1.66). A significantly reduced risk of lip cancer (SIR < 0.50) was observed among male physicians, teachers, religious workers, artistic workers, journalists, administrators, printers, waiters, and hairdressers. Among women, no occupations were associated with an increased risk of lip cancer., Conclusions: The incidence of lip cancer varies widely between outdoor and indoor occupations. Occupations involving outdoor activity and exposure to sunlight show the most elevated SIRs.

Police work may expose officers to various circumstances that have potential for increasing their risk of cancer, including traffic-related air pollution, night shift work and radiation from radars. In this study, we examined the incidence of cancer among Nordic male and female police officers. We utilize data from the Nordic Occupational Cancer (NOCCA) project, which linked census data on occupations from Finland, Iceland, Norway and Sweden to national cancer registries for the period 1961 to 2005. We report standardized incidence ratios (SIR) and 95% confidence intervals (CI) of selected cancers for each country by sex, age and calendar period. The cohort included 38 523 male and 1998 female police officers. As compared with the general population, male police officers had a 7% (95% CI: 4-9%) excess cancer risk, with elevated SIRs for various cancer sites, including prostate (SIR 1.19, 1.14-1.25), breast (SIR 1.77, 1.05-2.80), colon (SIR 1.22, 1.12-1.32) and skin melanoma (SIR 1.44, 1.28-1.60). Conversely, male police officers had a lower risk of lung cancer than the general population (SIR 0.72, 0.66-0.77). In female police officers, the SIR for cancer overall was 1.15 (0.98-1.34), and there was a slight excess of cancers of the breast (SIR 1.25, 0.97-1.59) and colon (SIR 1.21, 0.55-2.30). In conclusion, cancer incidence among the police officers was slightly higher than in the general population. Notably, SIRs were elevated for cancer sites potentially related to night shift work, namely colon, breast and prostate cancer., (© 2022 UICC.)

Background: There are studies suggesting that participation in musical activities may protect from cancer. On the other hand, some musicians have a lifestyle that might increase the risk of cancer. The objective of this study was to assess the cancer pattern of musicians in four Nordic countries., Material and Methods: This study combines census and cancer registry data from 1961 to 2005 for 13 million people from Finland, Iceland, Norway, and Sweden. Standardized incidence ratio (SIR) analyses were conducted with the cancer incidence rates for entire national populations used as reference rates., Results: There were 11,401 male and 3105 female musicians with 2039 cancer cases. The SIR for all sites combined was 1.02 (95% confidence interval 0.97-1.07) in men and 1.04 (0.94-1.15) in women. In male musicians, there were statistically significant excesses in oropharyngeal cancer (4.36, 2.73-6.60), esophageal cancer (2.08, 1.51-2.81), liver cancer (1.81, 1.26-2.52), and skin melanoma (1.40, 1.10-1.75). The risk was decreased in lip cancer (0.13, 0.02-0.48), stomach cancer (0.66, 0.50-0.82), and lung cancer (0.77, 0.65-0.90). In female musicians, there were no statistically significant SIRs in any of the cancer types studied, but the risk of breast cancer was significantly elevated in the age category of 70+ (1.52, 1.04-2.15). The overall SIR was stable over the 45 year period of observation, but strong decreases were observed in the SIRs of esophageal cancer, liver cancer, laryngeal cancer, and skin melanoma., Conclusion: Musicians have characteristics of indoor workers such as low incidence of lip cancer and high incidence of skin melanoma. The low incidence of lung cancer suggests that the prevalence of smoking among musicians is lower than in the general population while the elevated risk of alcohol-related cancer types suggest that drinking is likely more common among musicians. The cancer risk for all sites combined is still similar to that of the general population in the four countries studied.

Background: The International Agency for Research on Cancer (IARC) recently classified opium use as a Group 1 carcinogen. However, much remains to be studied on the relation between opium and cancer. We designed the Iranian Opium and Cancer (IROPICAN) study to further investigate the association of opium use and cancers of the head and neck, bladder, lung, and colon and rectum. In this paper, we describe the rationale, design, and some initial results of the IROPICAN Study., Methods: The IROPICAN is a multi-center case-control study conducted in 10 provinces of Iran. The cases were all histologically confirmed and the controls were selected from hospital visitors who were free of cancer, were not family members or friends of the cancer patients, and were visiting the hospital for reasons other than their own ailment. The questionnaires included detailed questions on opium use (including age at initiation, duration, frequency, typical amount, and route), and potential confounders, such as tobacco use (e.g., cigarettes, nass and water-pipe), and dietary factors. Biological samples, including blood and saliva, were also collected., Results: The validation and pilot phases showed reasonably good validity, with sensitivities of 70% and 69% for the cases and controls, respectively, in reporting opium use. The results also showed excellent reliability, with intra-class correlation coefficients of 0.96 for ever opium use and 0.88 (95% CI: 0.80, 0.92) for regular opium use. In the main phase, we recruited 3299 cancer cases (99% response rate) and 3477 hospital visitor controls (89% response rate). The proportion of ever-use of opium was 40% among cases and 18% among controls., Conclusion: The IROPICAN study will serve as a major resource in studies addressing the effect of opium on risk of cancers of the head and neck, bladder, lung, and colon and rectum., (© 2021 The Author(s). This is an open-access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.)

Kidney transplant recipients (KTRs) have an increased cancer risk compared to the general population, but absolute risks that better reflect the clinical impact of cancer are seldom estimated. All KTRs in Sweden, Norway, Denmark, and Finland, with a first transplantation between 1995 and 2011, were identified through national registries. Post-transplantation cancer occurrence was assessed through linkage with cancer registries. We estimated standardized incidence ratios (SIR), absolute excess risks (AER), and cumulative incidence of cancer in the presence of competing risks. Overall, 12 984 KTRs developed 2215 cancers. The incidence rate of cancer overall was threefold increased (SIR 3.3, 95% confidence interval [CI]: 3.2-3.4). The AER of any cancer was 1560 cases (95% CI: 1468-1656) per 100 000 person-years. The highest AERs were observed for nonmelanoma skin cancer (838, 95% CI: 778-901), non-Hodgkin lymphoma (145, 95% CI: 119-174), lung cancer (126, 95% CI: 98.2-149), and kidney cancer (122, 95% CI: 98.0-149). The five- and ten-year cumulative incidence of any cancer was 8.1% (95% CI: 7.6-8.6%) and 16.8% (95% CI: 16.0-17.6%), respectively. Excess cancer risks were observed among Nordic KTRs for a wide range of cancers. Overall, 1 in 6 patients developed cancer within ten years, supporting extensive post-transplantation cancer vigilance., (© 2020 The Authors. Transplant International published by John Wiley & Sons Ltd on behalf of Steunstichting ESOT.)

The incidence pattern of lichen planus (LP) and LP-related mortality are unknown. The aim of this study was to assess these factors, based on Finnish nationwide registry data including 13,378 women with LP diagnosed during 1969 to 2012. The incidence rate for LP in 2003 to 2012 was 28 per 100,000 woman-years age-adjusted to the European Standard Population. Mortality was assessed using the standardized mortality ratio (SMR) with national mortality rates as the reference. All-cause mortality was increased (SMR 1.07, 95% confidence interval (95% CI) 1.02-1.11), with excess mortality from Hodgkin lymphoma (SMR 6.73, 95% CI 1.83-17.2), non-Hodgkin lymphoma (SMR 1.68, 95% CI 1.11-2.44), cancer of the oral cavity (SMR 10.5, 95% CI 5.99-17.0), cancer of the tongue (SMR 7.25, 95% CI 3.13-14.3), infections (SMR 1.78, 95% CI 1.14-2.64), respiratory diseases (SMR 1.31, 95% CI 1.07-1.57), and diseases of the digestive system (SMR 1.39, 95% CI 1.09-1.75). In conclusion, LP is a common disease and patients seem to have an impaired long-term prognosis.

Purpose: Obesity increases the risk of several cancers, but the influence of bariatric surgery on the risk of individual obesity-related cancers is unclear. This study aimed to assess the impact of bariatric surgery on cancer risk in a multi-national setting., Materials and Methods: This cohort study included all adults with an obesity diagnosis identified from national patient registries in all Nordic countries (Denmark, Finland, Iceland, Norway and Sweden) from 1980 to 2012. Cancer risk in bariatric surgery patients was compared with non-operated patients with obesity. Multivariable Cox regression provided adjusted hazard ratios (HRs) with 95% confidence intervals (CIs). Age, sex, calendar year, country, length of follow-up, diabetes, chronic obstructive pulmonary disease and alcohol-related diseases were evaluated as confounders., Results: Among 482,572 participants with obesity, 49,096 underwent bariatric surgery. Bariatric surgery was followed by a decreased overall cancer risk in women (HR 0.86, 95% CI 0.80-0.92), but not in men (HR 0.98, 95% CI 0.95-1.01). The risk reduction was observed only within the first five post-operative years. Among specific tumours, HRs decreased for breast cancer (HR 0.81, 95% CI 0.69-0.95), endometrial cancer (HR 0.69, 95% CI 0.56-0.84) and non-Hodgkin lymphoma (HR 0.64, 95% CI 0.42-0.97) in female bariatric surgery patients, while the risk of kidney cancer increased in both sexes (HR 1.44, 95% CI 1.13-1.84)., Conclusion: Bariatric surgery may decrease overall cancer risk in women within the first five years after surgery. This decrease may be explained by a decreased risk of breast and endometrial cancer and non-Hodgkin lymphoma in women.

Objectives Maritime workers may be exposed to several occupational hazards at sea. The aim of this study was to assess cancer incidence among seafarers and fishermen in the Nordic countries and identify patterns in morbidity in the context of existing studies in this field. Methods A cohort of 81 740 male seafarers and 66 926 male fishermen was established from census data on 15 million citizens in the five Nordic countries. Using personal identity codes, information on vital status and cancer was linked to members of the cohort from the national population and cancer registries for the follow-up period 1961-2005. Standardized incidence ratios (SIR) were calculated applying national cancer incidence rates for each country and pooling results. Results The overall incidence of cancer was increased among the male seafarers [SIR 1.22, 95% confidence interval (CI) 1.19-1.23]. Significant excesses were observed for multiple cancer sites among the seafarers, while results for the fishermen were mixed. Lip cancer incidence was increased among both maritime populations. For mesothelioma (SIR 2.17, 95% CI 1.83-2.56 seafarers) and non-melanoma skin cancer (SIR 1.23, 95% CI 1.14-1.32 seafarers), incidence was increased among the seafarers. Conclusion In our cohort, seafaring was associated with a higher overall incidence of cancer compared to the general population. While the majority of cancers could not be linked to specific occupational factors, increases in mesothelioma, lip and non-melanoma-skin cancer indicate previous exposure to asbestos, ultraviolet radiation and potentially also chemicals with dermal carcinogenic properties at sea.

Context: Autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy (APECED) is an autoimmune endocrinopathy with severe and unpredictable course. The impact of APECED on mortality has not been determined., Objective: To assess overall and cause-specific mortality of patients with APECED., Design and Setting: A follow-up study of Finnish patients with APECED from 1971 to 2018. Causes and dates of death were collected from Finnish registries., Patients: Ninety-one patients with APECED., Main Outcome Measure: Overall and cause-specific standardized mortality ratios (SMRs) determined by comparing the observed numbers of death and those expected on the basis of respective population death rates in Finland., Results: The overall disease mortality was significantly increased (29 deaths, SMR 11; 95% confidence interval [CI] 7.2-16; P < 0.001). The relative risk (SMR) was highest in the youngest age groups but the absolute excess risk was similar (about 10 per 10 000 person-years) in all age categories. The highest SMRs were seen for endocrine and metabolic diseases (SMR 570; 95% CI, 270-1000; P < 0.001) and for oral and esophageal malignancies (SMR 170; 95% CI, 68-360; P < 0.001). Mortality was also increased for infections, diseases of digestive system, alcohol-related deaths, and for accidents. Due to the small number of cases we were unable to evaluate whether mortality was affected by disease severity., Conclusions: Patients with APECED have significantly increased mortality in all age groups. Highest SMRs are found for causes that are directly related to APECED but also for infections. Increased alcohol- and accident-related deaths may be influenced by psychosocial factors., (© Endocrine Society 2020.)

Background & Aims: Bariatric surgery might reduce overall mortality from obesity. We investigated whether the survival times of patients who have had bariatric surgery are similar to those of the general population and are longer than of obese individuals who did not receive surgery., Methods: We performed a population-based cohort study of persons with a diagnosis of obesity listed in nationwide registries from Nordic countries from 1980 through 2012. Bariatric surgery was analyzed in relation to all-cause mortality and the obesity-related morbidities cardiovascular disease, diabetes, cancer, and suicide. Poisson models provided standardized mortality ratios (SMRs) with 95% confidence intervals (CIs). Multivariable Cox regression provided hazard ratios (HRs) for mortality in participants who did and did not have surgery., Results: Among 505,258 participants, 49,977 had bariatric surgery. Overall all-cause SMR was increased after surgery (1.94; 95% CI, 1.83-2.05) and increased with longer follow-up, to 2.28 (95% CI, 2.07-2.51) at ≥15 years after surgery. SMRs were increased for cardiovascular disease (2.39; 95% CI, 2.17-2.63), diabetes (3.67; 95% CI, 2.85-4.72), and suicide (2.39; 95% CI, 1.96-2.92) but not for cancer (1.05; 95% CI, 0.95-1.17); SMRs increased with time. In obese participants who did not have surgery, all-cause SMR was 2.15 (95% CI, 2.11-2.20), which remained stable during follow-up. Compared with obese participants who did not have surgery, patients who had bariatric surgery had decreased overall mortality from all causes (HR, 0.63; 95% CI, 0.60-0.66), cardiovascular disease (HR, 0.57; 95% CI, 0.52-0.63), and diabetes (HR, 0.38; 95% CI, 0.29-0.49) but increased mortality from suicide (HR, 1.68; 95% CI, 1.32-2.14). Cancer mortality was decreased overall (HR, 0.84; 95% CI, 0.76-0.93) but increased at ≥15 years of follow-up (HR, 1.20; 95% CI, 1.02-1.42)., Conclusions: In a study of persons with a diagnosis of obesity listed in nationwide registries of Nordic countries, we found that obese patients who have bariatric surgery have longer survival times than obese individuals who did not have bariatric surgery, but their mortality is higher than that of the general population and increases with time. Obesity-related morbidities could account for these findings., (Copyright © 2019 AGA Institute. Published by Elsevier Inc. All rights reserved.)

Background: Cancer is currently one of the most important factors affecting the long-term health and survival of heart transplant patients. Material and methods: We calculated the standardized incidence ratios (SIR) for different cancer sites and the cancer-specific standardized mortality ratio (SMR) by linking a cohort of 479 adult heart transplant recipients transplanted in 1985-2014 (4491.6 person-years of follow-up) with data from the national Finnish Cancer Registry until the end of 2015, and with the data from the Statistics Finland's national registry of causes of death. Results: A total of 267 cancers occurred in 143 patients (SIR 6.0; 95% confidence interval (CI) 5.3-6.7). The SIR for overall cancer was considerably higher for men (SIR 6.7; 95% CI 5.9-7.5) than for women (1.4; 95% CI 0.6-2.6). Most frequent cancers were non-melanoma skin cancers (basal cell carcinoma 83 cases, squamous cell skin cancer (SCC) 56 cases), followed by Non-Hodgkin lymphoma (NHL) (36 cases), lung cancer (17), cancer of prostate (16) and cancer of kidney (12). SIRs were highest for SCC (51.9; 95% CI 39.2-67.4), lip cancer (47.4; 95% CI 19.1-97.7), cancer of tongue (26.3; 95% CI 7.2-67.4), and NHL (25.7; 95% CI 18.0-35.6). For most cancers, SIRs increased steadily by time since transplantation. Cancer mortality was three times higher for heart transplant recipients than for the population (SMR 3.1; 95% CI 2.1-4.1). Conclusions: Both cancer incidence and mortality are remarkably increased after heart transplantation, with the relative incidence most elevated for SCC, lip and other oral cancers, and for NHL.

The Nordic countries have comprehensive, population-based health and medical registries linkable on individually unique personal identity codes, enabling complete long-term follow-up. The aims of this study were to describe the NorTwinCan cohort established in 2010 and assess whether the cancer mortality and incidence rates among Nordic twins are similar to those in the general population. We analyzed approximately 260,000 same-sexed twins in the nationwide twin registers in Denmark, Finland, Norway and Sweden. Cancer incidence was determined using follow-up through the national cancer registries. We estimated standardized incidence (SIR) and mortality (SMR) ratios with 95% confidence intervals (CI) across country, age, period, follow-up time, sex and zygosity. More than 30,000 malignant neoplasms have occurred among the twins through 2010. Mortality rates among twins were slightly lower than in the general population (SMR 0.96; CI 95% [0.95, 0.97]), but this depends on information about zygosity. Twins have slightly lower cancer incidence rates than the general population, with SIRs of 0.97 (95% CI [0.96, 0.99]) in men and 0.96 (95% CI [0.94, 0.97]) in women. Testicular cancer occurs more often among male twins than singletons (SIR 1.15; 95% CI [1.02, 1.30]), while cancers of the kidney (SIR 0.82; 95% CI [0.76, 0.89]), lung (SIR 0.89; 95% CI [0.85, 0.92]) and colon (SIR 0.90; 95% CI [0.87, 0.94]) occur less often in twins than in the background population. Our findings indicate that the risk of cancer among twins is so similar to the general population that cancer risk factors and estimates of heritability derived from the Nordic twin registers are generalizable to the background populations.

Diabetes and cancer are common diseases both with enormous impact on health burden globally. The increased risk of several types of cancer among people with type 2 diabetes mellitus has been indicated repeatedly. This study aimed at exploring and describing the association between type 2 diabetes and cancer incidence. A cohort of 428,326 people with type 2 diabetes was identified from the Finnish National Diabetes Register and followed up through a register linkage with the Finnish Cancer Registry for cancer incidence during 1988-2014. A total of 74,063 cases of cancer occurred in this cohort in 4.48 million person-years. This accounted for 16% more than the expected cancer incidence in the Finnish general population; the standardized incidence ratio (SIR) was 1.16 (95% confidence interval [CI] 1.15-1.16). There was a statistically significant excess of cancers of lip (SIR = 1.40, CI = 1.28-1.53), liver (SIR = 2.44, CI = 2.35-2.53), pancreas (SIR = 1.75, CI = 1.70-1.79), stomach (SIR = 1.22, CI = 1.18-1.26), colon (SIR = 1.22, CI = 1.19-1.25), gallbladder and bile ducts (SIR = 1.29, CI = 1.21-1.36), non-melanoma skin (SIR = 1.18, CI = 1.15-1.22), kidney (SIR = 1.42, CI = 1.37-1.47), bladder (SIR = 1.17, CI = 1.13-1.21), and thyroid (SIR = 1.22, CI = 1.12-1.31). There was a small statistically significant decrease in prostate cancer incidence (SIR = 0.95, CI = 0.93-0.96). This study showed an association between type 2 diabetes mellitus and the incidence of cancer at numerous sites in the Finnish population.

Background: Placentation is characterized by extensive cell proliferation and neovascularization, which is similar to the processes observed in the development of cancer. Nonetheless, little is known about the relation between abnormal placentation, such as placental abruption, and cancer., Material and Methods: Data on women with placental abruption in a singleton pregnancy between 1971 and 2005 (n = 7804) were collected from the Finnish Hospital Discharge Registry and the Finnish Medical Birth Registry. The cohort was then linked with the Finnish Cancer Registry records until the end of 2013. Standardized incidence ratios (SIRs) were calculated for different cancers by dividing the observed numbers of cancers by those expected. The expected numbers were based on national cancer incidence rates., Results: During follow-up, 597 cancers were found among women with a history of placental abruption. The overall risk of cancer was not increased (SIR 0.95, 95% CI 0.88-1.02). However, the history of placental abruption was associated with an increased risk of lung cancer (SIR 1.51, 95% CI 1.05-2.10) and thyroid cancer (SIR 1.47, 95% CI 1.04-2.02). A decreased risk was found for breast cancer (SIR 0.85, 95% CI 0.75-0.96). The risk of rectal cancer was also decreased, although these numbers were small (SIR 0.49, 95% CI 0.20-1.01)., Conclusions: Overall, the risk of lung cancer was increased, and the risk of breast cancer decreased, in women with a history of placental abruption. These observations can be explained to some extent by risk factors or risk markers for placental abruption. The increased risk of thyroid cancer may be explained by surveillance bias.

Background : Alcohol and tobacco strongly increases the risk of cancers of the tongue, mouth, pharynx, larynx, and oesophagus, and are also established risk factors for cancer of the liver, colon, and rectum. It is well documented that these habits are unequally distributed among occupational groups. Most occupational cohort studies lack information on these potentially important confounders, and may therefore be prone to bias. Aim : The aim of the study is to present Nordic standardized incidence ratios (SIRs) for alcohol and tobacco related cancer by occupation, after adjustment for alcohol and tobacco, and to compare to the unadjusted SIRs. Material and Methods : The study is based on the Nordic Occupational Cancer (NOCCA) database. We used confirmatory factor analysis models for simultaneous analysis of the cancer sites related to alcohol and tobacco, to obtain factors that allow for computation of adjusted expected numbers from the reference rates. We then calculated adjusted SIRs for the relevant cancer sites for each occupation. Results : For some occupations and cancers, the changes of risk estimates were striking, from significantly high to significantly low and vice versa. Among Nordic farmers, unadjusted SIRs for cancer of the mouth and oesophagus were 0.56 (95% confidence interval (CI) 0.51⁻0.61) and 0.67 (CI 0.63⁻0.70), respectively. After adjustment, estimates changed to 1.10 (CI 1.01⁻1.21) and 1.16 (CI 1.10⁻1.22). Unadjusted SIR for pharynx cancer among wood workers was 0.83 (CI 0.75⁻0.91), adjusted SIR was 1.14 (CI 1.03⁻1.25). For larynx cancer, results in the opposite direction were seen: unadjusted SIR for economically inactive was 1.38 (CI 1.31⁻1.46) while the adjusted SIR was 0.91 (CI 0.86⁻0.96). Conclusions : Adjustment for the latent indicators of alcohol and tobacco consumption changed risk estimates for several occupations, gave a less confounded description of risk, and may guide in the identification of true risk factors.

We assessed the association of surgically verified endometriosis and risk of non-gynecological cancers according to the type of endometriosis (i.e., ovarian, peritoneal and deep infiltrating endometriosis). All diagnoses of endometriosis combined with relevant procedural codes were identified from the Finnish Hospital Discharge Register 1987-2012. Non-gynecological cancers diagnosed after the endometriosis diagnosis were obtained from the Finnish Cancer Registry. The cohort of 49,933 women with surgically verified endometriosis and the sub-cohorts of ovarian (n = 23,210), peritoneal (n = 20,187), and deep infiltrating (n = 2,372) endometriosis were analyzed separately. The endometriosis cohort contributed 838,685 person-years of follow-up and the Finnish female population served as the reference cohort. The standardized incidence ratio (SIR) and 95% confidence interval (95%CI) was calculated for each cancer separately. The follow-up ended at emigration, death or on the 31st of December 2014. The non-gynecological cancer risk was not increased among women with endometriosis (SIR 1.03, 95%CI 0.98-1.08). Endometriosis was associated with an increased risk of thyroid cancer in the entire cohort (SIR 1.43, 95%CI 1.23-1.64) and in the sub-cohorts of ovarian and peritoneal endometriosis. We found a decreased risk of mouth and pharynx cancer (SIR 0.60, 95%CI 0.41-0.80), and of pancreatic cancer (SIR 0.76, 95%CI 0.58-0.96). The incidence of basal cell carcinoma was elevated in the entire cohort (SIR 1.18, 95%CI 1.10-1.25) and in the sub-cohorts of ovarian and peritoneal endometriosis. In conclusion, women with surgically verified endometriosis have an altered risk of only few non-gynecological cancers., (© 2018 UICC.)

Background: Alcohol consumption is an important and preventable cause of cancer. The aim of this study was to quantify the proportion of the cancer burden in the Nordic countries linked to alcohol and estimate the potential for cancer prevention by changes in alcohol consumption., Methods: Using the Prevent macro-simulation model, the number of cancer cases in the Nordic countries over a 30-year period (2016-2045) was modelled for six sites, under different scenarios of changing alcohol consumption, and compared to the projected number of cases if constant alcohol consumption prevailed. The studied sites were colorectal, post-menopausal breast, oral cavity and pharynx, liver, larynx as well as oesophageal squamous cell carcinoma. The alcohol consumption was based on the categories of non-drinkers/occasional drinkers, light drinkers (<=12.5 g alcohol per day), moderate drinkers (>12.5 and ≤ 50 g/day) and heavy drinkers (>50 g/day)., Results: About 83,000 cancer cases could be avoided in the Nordic countries in a 30-year period if alcohol consumption was entirely eliminated, which is 5.5% of the expected number of cases for the six alcohol-related cancer types. With a 50% reduction in the proportion with moderate alcohol consumption by year 2025, 21,500 cancer cases could be avoided. The number of avoidable cases was highest for post-menopausal breast and colorectal cancer, but the percentage was highest for oesophageal squamous cell carcinoma., Conclusion: The results from this study can be used to understand the potential impact and significance of primary prevention programmes targeted towards reducing the alcohol consumption in the Nordic countries., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

Objective: The aim of this study was to assess the cancer risk in a cohort of Finnish patients with systemic lupus erythematosus (SLE) when followed over the long term., Method: The cohort consisted of 182 female and 23 male SLE patients treated at the Helsinki University Central Hospital from 1967 to 1987. The cohort was linked to the Finnish Cancer Registry and followed for cancer incidence from 1967 to 2013. Standardized incidence ratios (SIRs) were calculated by dividing the number of observed cases by the number of expected cases for different types of cancer., Results: The mean duration of follow-up was 25.7 years. Forty-five patients out of 205 were diagnosed with cancer, with an increased risk of overall malignancy [SIR 1.90, 95% confidence interval (CI) 1.39-2.54, p < 0.001]. The incidences of soft-tissue sarcoma (SIR 12.1, 95% CI 1.47-43.7, p < 0.05), non-Hodgkin's lymphoma (SIR 12.1, 95% CI 5.82-22.3, p < 0.001), and kidney cancer (SIR 7.79, 95% CI 2.53-18.2, p < 0.01) were significantly elevated., Conclusion: This long-term study confirms that patients with SLE have an increased risk of cancer, particularly non-Hodgkin's lymphoma and kidney cancer.

Background: Tobacco smoking is a leading cause of cancer and the most preventable cause of cancer worldwide. The aim of this study was to quantify the proportion of the cancer burden in the Nordic countries linked to tobacco smoking and estimate the potential for cancer prevention by changes in smoking prevalence., Methods: The Prevent macro-simulation model was used, estimating the future number of cancer cases in the Nordic countries over a 30-year period (2016-2045), for 13 cancer sites, under different scenarios of changing smoking prevalence, and compared to the projected number of cases if constant prevalence prevailed., Results: A total of 430,000 cancer cases, of the 2.2 million expected for the 13 studied cancer sites, could be avoided in the Nordic countries over the 30-year period if smoking was eliminated from 2016 onwards. If prevalence of smoking is reduced to 5% by year 2030 and to 2% by 2040, 230,000 cancer cases could be avoided. The largest proportion of cancers can be avoided in Denmark, where smoking prevalence is the highest, and similar to the prevalence in many European countries., Conclusion: A large amount of cancers could be avoided in the Nordic countries if smoking prevalence was reduced. The results from this study can be used to understand the potential impact and significance of primary prevention programmes targeted towards reducing the prevalence of tobacco smoking in the Nordic countries., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

Background and purpose - Metal-on-metal (MoM) total hip arthroplasty (THA) and hip resurfacing arthroplasty (HRA) have been widely used during the early 21st century. We assessed the midterm risk of cancer of patients treated with modern MoM hip implants compared with patients with non-MoM hip implants and the general Finnish population with special interest in soft tissue sarcomas and basalioma due to the findings of our previous report. Patients and methods - All large-diameter head MoM THAs and hip resurfacings performed in Finland between 2001 and 2010 were extracted from the Finnish Arthroplasty Register (10,728 patients). Patients who underwent conventional THA formed the non-MoM reference cohort (18,235 patients). Data on cancer cases up to 2014 were extracted from the Finnish Cancer Registry. The relative risk of cancer in the general population was expressed as the ratio of observed to expected number of cases, i.e., standardized incidence ratio (SIR). Poisson regression analysis was used to compare the cancer risk between the cohorts. The mean follow-up was 7.4 years (1-14) in the MoM cohort and 8.4 years (1-14) in the non-MoM cohort. Results - The overall risk of cancer in the MoM cohort was comparable to the general Finnish population (SIR 0.9, 95% CI 0.9-1.0). Risk of basalioma in the MoM cohort was higher than in the general Finnish population (SIR 1.2, CI 1.1-1.4) and higher than in the non-MoM cohort in the stratified regression analysis (RR 1.2, CI 1.0-1.4, p = 0.02). The SIR of soft-tissue sarcoma in the MoM cohort was 1.4 (CI 0.6-2.8); the incidence was same as in the non-MoM cohort. Interpretation - Metal-on-metal hip implants are not associated with an increased overall risk of cancer during midterm follow-up.

Cancer after liver transplantation (LT) constitutes a threat also for young recipients, but cancer risk factors are usually absent in children and large studies on the cancer risk profile in young LT recipients are scarce. Data of patients younger than 30 years who underwent LT during the period 1982-2013 in the Nordic countries were linked with respective national cancer registries to calculate standardized incidence ratios (SIRs). A total of 37 cancer cases were observed in 923 patients with 7846 person-years of follow-up. The SIR for all cancer types, compared with the matched general population, was 9.8 (12.4 for males and 7.8 for females). Cumulative incidence of cancer adjusted for the competing risk of death was 2% at 10 years, 6% at 20 years, and 22% at 25 years after LT. Non-Hodgkin lymphoma was the most common cancer type (n = 14) followed by colorectal (n = 4) and hepatocellular cancer (n = 4). Age was a significant risk factor for cancer, and the absolute risk of most cancers (except for lymphoma) increased considerably in young adults older than 20 years. The cancer risk pattern is different in pediatric and young LT patients compared with adult recipients. The striking increase in cancer incidence in young adulthood after the second decade of life deserves further consideration in transition programs., (© 2018 by the American Association for the Study of Liver Diseases.)

Background: The Nordic Cancer Registries are among the oldest population-based registries in the world, with more than 60 years of complete coverage of what is now a combined population of 26 million. However, despite being the source of a substantial number of studies, there is no published paper comparing the different registries. Therefore, we did a systematic review to identify similarities and dissimilarities of the Nordic Cancer Registries, which could possibly explain some of the differences in cancer incidence rates across these countries., Methods: We describe and compare here the core characteristics of each of the Nordic Cancer Registries: (i) data sources; (ii) registered disease entities and deviations from IARC multiple cancer coding rules; (iii) variables and related coding systems. Major changes over time are described and discussed., Results: All Nordic Cancer Registries represent a high quality standard in terms of completeness and accuracy of the registered data., Conclusions: Even though the information in the Nordic Cancer Registries in general can be considered more similar than any other collection of data from five different countries, there are numerous differences in registration routines, classification systems and inclusion of some tumors. These differences are important to be aware of when comparing time trends in the Nordic countries.

The association between Lichen planus (LP) and cancer has been under debate for decades. We studied the connection via population-based Finnish register data. All women with the diagnosis of LP (n = 13,100) were identified from the Finnish Hospital Discharge Registry from 1969-2012. These patients were linked with subsequent cancer diagnoses from the Finnish Cancer Registry until 2014. Standardized incidence ratios (SIRs) were counted for different cancers by dividing the observed numbers of cancers by expected numbers, which were based on national cancer incidence rates. In total, 1,520 women with LP were diagnosed with cancer (SIR 1.15, 95% confidence interval [CI] 1.09-1.20). LP was associated with an increased risk of cancer of lip (SIR 5.17, 95% CI 3.06-8.16), cancer of tongue (SIR 12.4, 95% CI 9.45-16.0), cancer of oral cavity (SIR 7.97, 95% CI 6.79-9.24), cancer of esophagus (SIR 1.95, 95% CI 1.17-3.04), cancer of larynx (SIR of 3.47, 95% CI 1.13-8.10) and cancer of vulva (SIR 1.99, 95% CI 1.18-3.13). The risk of cancer was not increased in other locations where LP manifests (pharynx and skin). Patients with diagnosed LP have an increased risk of developing cancer of lip, tongue, oral cavity, esophagus, larynx and vulva. These data are important when considering treatment and follow-up of patients with LP diagnosis., (© 2017 UICC.)

Population-based Finnish Maternity Cohort (FMC) comprises 2M first trimester sera collected from 1M women during 33 years. Informed consent is by the opt-out principle, and linkages with cancer and population registries provide a base for over time and over generation studies. Follow-up for 17M person-years by the end of 2014 can identify 39,700 cases of invasive cancer and 18,900 cases of premalignant breast and cervix lesions, and basal cell carcinoma diagnosed after serum sampling. For women with multiple pregnancies, serial samples taken before cancer diagnosis are available. Offspring of the women have developed more than 4000 cancers. For 100,000 individuals, samples taken during the pregnancies of both their mothers and grandmothers enable familial cancer studies. FMC continues to collect samples, and surveillance of exposures or interventions like vaccination programs is feasible. In summary, the FMC is a unique, accessible biobank for epidemiological, biomarker, and surveillance studies on cancer., (© 2017 The Authors. Cancer Medicine published by John Wiley & Sons Ltd.)

Background Earlier research suggests poorer outcome of cancer care among people with severe mental illness (SMI). Aims To assess the effect of stage at presentation, comorbidities and treatment on differences in survival among cancer patients with and without a history of SMI in Finland. Method The total population with a first cancer diagnosis in 1990-2013 was drawn from the Finnish Cancer Registry. Hospital admissions because of SMI and deaths were obtained from administrative registers. We calculated Kaplan-Meier estimates and Cox regression models to examine survival differences. Results We found excess mortality in people with a history of psychotic and substance use disorders. Cancer stage and comorbidity did not explain mortality differences. Controlling for cancer treatment decreased the differences. The mortality gap between patients with psychosis and cancer patients without SMI increased over time. Conclusions Integrated medical and psychiatric care is needed to improve outcomes of cancer care among patients with SMI., Competing Interests: Declaration of interestNone., (© The Royal College of Psychiatrists 2017.)

Purpose: The cohort was set up to study the impact of lifestyle factors in early adulthood on disease outcomes, with a focus on assessing the influence of body composition and physical performance in early adulthood on subsequent cancer risk., Participants: Men born in 1958 who performed their military service between the ages of 17 and 30 years were included in this study (n=31 158). They were eligible for military service if they were healthy or had only minor health problems diagnosed at the beginning of their service. Men with chronic illnesses requiring regular medication or treatment were not eligible for service. Comprehensive health data including diagnosed illnesses, anthropometric measures and health behaviour were collected at the beginning and at the end of military service, including data from medical check-ups., Findings to Date: During the follow-up, 1124 new cancer cases were diagnosed between baseline (ie, end of the military service for each individual) and end of the year 2014. In the end of the follow-up, 91% of the study participants were still alive. Overweight (body mass index (BMI) ≥25 kg/m 2 ) and obesity (BMI ≥30 kg/m 2 ) were associated with an overall increased risk of cancer. A good or excellent physical condition significantly reduced cancer risk., Future Plans: The dataset offers the possibility of linkage with other databases, such as the Finnish Cancer Registry (eg, primary site of the tumour, morphology, time of detection, spreading and primary treatment), vital statistics (date of emigration or deaths), censuses (socioeconomic indicators), hospital discharge data (comorbidity) and population surveys (life habits)., Competing Interests: Competing interests: None declared., (© Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.)

Background: Several types of cancers are causally linked to overweight and obesity, which are increasing in the Nordic countries. The aim of this study was to quantify the proportion of the cancer burden linked to overweight and obesity in the Nordic countries and estimate the potential for cancer prevention., Methods: Under different prevalence scenarios of overweight and obesity, the number of cancer cases in the Nordic countries in the next 30 years (i.e. 2016-2045) was estimated for 13 cancer sites and compared to the projected number of cancer cases if the prevalence stayed constant. The Prevent macro-simulation model was used., Results: Over the period 2016-2045, 205,000 cancer cases out of the 2.1 million expected for the 13 cancer sites (9.5%) that have been studied, could be avoided in the Nordic countries by totally eliminating overweight and obesity in the target population. The largest proportional impact was found for oesophageal adenocarcinoma (24%), and the highest absolute impact was observed for colon (44638) and postmenopausal breast cancer (41135)., Conclusion: Decreased prevalence of overweight and obesity would reduce the cancer burden in the Nordic countries. The results from this study form an important step to increase awareness and priorities in cancer control by controlling overweight and obesity in the population., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

Background: There is inadequate evidence for the carcinogenicity of cobalt and cobalt compounds in humans. Consequently, the International Agency for Research on Cancer (IARC) has evaluated cobalt metal without tungsten carbide as possibly carcinogenic to humans (Group 2B). The aim of the study was to assess the risk of cancer among workers employed in a Finnish cobalt plant since the beginning of production in 1968., Methods: The study cohort consisted of all males employed by the Finnish cobalt plant for at least a year during 1968-2004. The follow-up for cancer was performed by studying the files of the Finnish Cancer Registry, using personal identity codes as a key. The cohort was divided into subcohorts by exposure levels. Standardised incidence ratios (SIRs) and 95% confidence intervals (95% CIs) were calculated as ratios of the observed numbers of cancer cases and the numbers expected on the basis of incidence rates in the population of the same region., Results: The follow-up cohort consisted of 995 men with 26,083 person-years. During the follow-up period, 92 cases of cancer were diagnosed (SIR 1.00, 95% CI 0.81-1.22), six of which were lung cancer cases (SIR 0.50; 95% CI 0.18-1.08). The only cancer type with increased incidence was tongue cancer (three cases, SIR 7.39; 95% CI 1.52-21.6). We observed no dose-response effect across the different exposure levels and the incidence of any cancer type., Conclusions: The results suggest that occupational exposure to cobalt is not associated with an increased overall cancer risk or lung cancer risk among cobalt workers. Because of the small number of cancer cases the results must be interpreted with caution.

Lay people and health professionals are increasingly interested in health issues in their region. The high-quality cancer and population registries in the Nordic countries allow fine spatial and temporal visualization of mapped data. This article describes - with real-data examples - a mapping method developed in Finland for such visualization but also utilized for data from numerous other countries and non-cancer outcomes. The Finnish smoothing is based on weighting small-area specific observations with population sizes and distance without losing the interpretability of the values. The approach has essentially improved the readability of spatio-temporal trends of incidence and mortality rates of cancers and has been applied in many studies. With help of the tool, decision makers can understand the key message of existing data and use it more effectively in their efforts to provide better health care services., (Copyright © 2016 Elsevier Ltd. All rights reserved.)

Objectives: To estimate total and cause-specific mortality after international peacekeeping deployments among the Finnish military peacekeeping personnel in comparison to the general population of similar age and sex., Design: A register-based study of a cohort of military peacekeeping personnel in 1990-2010 followed for mortality until the end of 2013. Causes of death were obtained from the national Causes of Death Register. The standardised mortality ratio (SMR) for total and cause-specific mortality was calculated as the ratio of observed and expected number of deaths., Setting: Finland (peacekeeping operations in different countries in Africa, Asia and in an area of former Yugoslavia in Europe)., Participants: 14 584 men and 418 women who had participated in international military peacekeeping operations ending between 1990 and 2010., Interventions: Participation in military peacekeeping operations., Main Outcome: Total and cause-specific mortality., Results: 209 men and 3 women died after their peacekeeping service. The SMR for all-cause mortality was 0.55 (95% CI 0.48 to 0.62). For the male peacekeeping personnel, the SMR for all diseases was 0.44 (95% CI 0.35 to 0.53) and for accidental and violent deaths 0.69 (95% CI 0.57 to 0.82). The SMR for suicides was 0.71 (95% CI 0.53 to 0.92)., Conclusions: Even though military peacekeeping personnel are working in unique and often stressful conditions, their mortality after their service is lower compared with the general population. Military peacekeeping personnel appear to be a selected population group with low general mortality and no excess risk of any cause of death after peacekeeping service., Competing Interests: Conflicts of Interest: None declared., (Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.)

Importance: Estimates of familial cancer risk from population-based studies are essential components of cancer risk prediction., Objective: To estimate familial risk and heritability of cancer types in a large twin cohort., Design, Setting, and Participants: Prospective study of 80,309 monozygotic and 123,382 same-sex dizygotic twin individuals (N = 203,691) within the population-based registers of Denmark, Finland, Norway, and Sweden. Twins were followed up a median of 32 years between 1943 and 2010. There were 50,990 individuals who died of any cause, and 3804 who emigrated and were lost to follow-up., Exposures: Shared environmental and heritable risk factors among pairs of twins., Main Outcomes and Measures: The main outcome was incident cancer. Time-to-event analyses were used to estimate familial risk (risk of cancer in an individual given a twin's development of cancer) and heritability (proportion of variance in cancer risk due to interindividual genetic differences) with follow-up via cancer registries. Statistical models adjusted for age and follow-up time, and accounted for censoring and competing risk of death., Results: A total of 27,156 incident cancers were diagnosed in 23,980 individuals, translating to a cumulative incidence of 32%. Cancer was diagnosed in both twins among 1383 monozygotic (2766 individuals) and 1933 dizygotic (2866 individuals) pairs. Of these, 38% of monozygotic and 26% of dizygotic pairs were diagnosed with the same cancer type. There was an excess cancer risk in twins whose co-twin was diagnosed with cancer, with estimated cumulative risks that were an absolute 5% (95% CI, 4%-6%) higher in dizygotic (37%; 95% CI, 36%-38%) and an absolute 14% (95% CI, 12%-16%) higher in monozygotic twins (46%; 95% CI, 44%-48%) whose twin also developed cancer compared with the cumulative risk in the overall cohort (32%). For most cancer types, there were significant familial risks and the cumulative risks were higher in monozygotic than dizygotic twins. Heritability of cancer overall was 33% (95% CI, 30%-37%). Significant heritability was observed for the cancer types of skin melanoma (58%; 95% CI, 43%-73%), prostate (57%; 95% CI, 51%-63%), nonmelanoma skin (43%; 95% CI, 26%-59%), ovary (39%; 95% CI, 23%-55%), kidney (38%; 95% CI, 21%-55%), breast (31%; 95% CI, 11%-51%), and corpus uteri (27%; 95% CI, 11%-43%)., Conclusions and Relevance: In this long-term follow-up study among Nordic twins, there was significant excess familial risk for cancer overall and for specific types of cancer, including prostate, melanoma, breast, ovary, and uterus. This information about hereditary risks of cancers may be helpful in patient education and cancer risk counseling.

Background: Many studies have previously revealed evidence of an association between grand multiparity (five or more deliveries) and gynaecological cancer. Oestrogen has an impact on cancer formation and the amount of circulating oestrogen is significantly higher during pregnancy. Also the lifestyle of grand multiparous women differs somewhat from the average population. Considering these factors it is plausible that also non-gynaecological cancers are associated with multiparity. The aim of our study was to determine cancer incidence among grand multiparous women, with special attention to non-gynaecological cancers., Material and Methods: All 102 541 women alive in 1974-2011 and having had at least five deliveries were identified in the Finnish Population Register and followed up for cancer incidence through the Finnish Cancer Registry to the end of 2011. Standardised incidence ratios (SIRs) were defined as ratios between observed and expected numbers of cases, the latter ones based on incidence in the entire Finnish female population., Results: The overall incidence of non-gynaecological cancers was the same as in the reference population (SIR 0.98, 95% confidence interval 0.90-1.06). The incidence of cancers of the gall-bladder (SIR 1.42, 1.26-1.58), biliary tract (1.19, 1.04-1.35) and kidney (1.22, 1.14-1.31) was increased. There were significantly fewer cases than expected of urinary bladder cancer (SIR 0.70, 0.61-0.78), lung cancer (0.87, 0.81-0.92), colon cancer (0.94, 0.89-0.99) and all types of skin cancers. As a consequence of the decreased incidence of gynaecological cancers (SIR 0.74, 0.71-0.77) and breast cancer (0.60, 0.58-0.61), the SIR for cancer overall was 0.84 (0.83-0.85)., Conclusion: The study demonstrated that grand multiparous women have a similar overall risk of non-gynaecological cancers as other women, despite significant differences in some specific forms of cancer.

A diet with restricted energy content reduces the occurrence of cancer in animal experiments. It is not known if the underlying mechanism also exists in human beings. To determine whether cancer incidence is reduced among patients with anorexia nervosa who tend to have a low intake of energy, we carried out a retrospective cohort study of 22 654 women and 1678 men diagnosed with anorexia nervosa at ages 10-50 years during 1968-2010 according to National Hospital Registers in Sweden, Denmark and Finland. The comparison group consisted of randomly selected persons from population registers who were similar to the anorexia nervosa patients in respect to sex, year of birth and place of residence. Patients and population comparisons were followed for cancer by linkage to Cancer Registries. Incidence rate ratios (IRR) were estimated using Poisson models. In total, 366 cases of cancer (excluding non-melanoma skin cancer) were seen among women with anorexia nervosa, and the IRR for all cancer sites was 0.97 (95% CI = 0.87-1.08) adjusted for age, parity and age at first child. There were 76 breast cancers corresponding to an adjusted IRR of 0.61 (95% CI = 0.49-0.77). Significantly increased IRRs were observed for esophageal, lung, and liver cancer. Among men with anorexia nervosa, there were 23 cases of cancer (age-adjusted IRR = 1.08; 95% CI = 0.71-1.66). There seems to be no general reduction in cancer occurrence among patients with anorexia nervosa, giving little support to the energy restriction hypothesis.

Aims: To study cancer risk patterns among waiters in the Nordic countries., Methods: We identified a cohort of 16,134 male and 81,838 female waiters from Denmark, Finland, Iceland, Norway and Sweden. During the follow-up period from 1961 to 2005, we found that 19,388 incident cancer cases were diagnosed. Standardised incidence ratio (SIR) was defined as the observed number of cancer cases divided by the expected number, based on national age, time period and gender-specific cancer incidence rates in the general population., Results: The SIR of all cancers in waiters, in the five countries combined, was 1.46 (95% CI 1.41-1.51) in men and 1.09 (1.07-1.11) in women. In male waiters, the SIR decreased from 1.79 (1.63-1.96) in 1961-1975, to 1.33 (1.26-1.40) in 1991-2005, but remained stable among women. The SIR among male waiters was highest for cancers in the pharynx (6.11; 95% CI 5.02-7.37), oral cavity (4.91; 95% CI 3.81-6.24) and tongue (4.36; 95% CI 3.13-5.92); and in female waiters, in the larynx (2.17; 95% CI 1.63-2.82), oral cavity (1.96; 95% CI 1.60-2.34) and lung (1.89; 95% CI 1.80-1.99)., Conclusions: The risk of cancer among waiters was higher than in the general population. The elevated incidence in some cancer sites can likely be explained by higher alcohol consumption, the prevalence of smoking and occupational exposure to tobacco smoke. Hopefully, the incidence of cancer among waiters will decrease in the future, due to the banning of tobacco smoking in restaurants and bars in the Nordic countries., (© 2015 the Nordic Societies of Public Health.)

The prevalence of life habits may vary substantially within a country. Incidence maps of strongly related diseases can illustrate the distribution of these life style habits. In this study we explored the spatial variation in Belgium for different cancers related to alcohol and/or tobacco. From the Belgian Cancer Registry, municipality specific World Standardised incidence rates for the years 2004-2011 are used to create detailed smoothed cancer maps by subsite or histology for cancers of oral cavity, pharynx, larynx, oesophagus, liver and lung. Cancer incidence is compared both visually (from incidence maps) and with Poisson regression analysis using mortality from chronic liver disease and chronic obstructive pulmonary disease as a proxy for alcohol and tobacco prevalence, respectively. The incidence rates for oral cavity, pharyngeal and laryngeal cancer were comparable with the alcohol gradient. However, glottic cancer revealed a pattern that was more comparable with lung cancer. These two tumour types resembled more closely to the smoking pattern. Oesophageal cancer showed two patterns: squamous cell carcinoma was highly comparable with the background alcohol consumption, while adenocarcinoma was unrelated to one of our two proxies. Our approach and results are an encouraging example how data from a young cancer registry can be used in studies describing the regional cancer burden. The results can be useful for primary prevention to increase awareness for the public, authorities and health care professionals in specific subpopulations., (Copyright © 2014 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Most studies that have evaluated the association between anti-diabetic medication and cancer risk have suffered from methodological drawbacks. To avoid time-related biases, we evaluated the effect of treatment duration on the cancer risk among naive users of anti-diabetic medication as compared to non-users. In addition, we addressed the influence of common risk factors such as smoking and BMI. The study population comprised 23,394 participants of FINRISK surveys. Data on cancer and anti-diabetic medication were linked with the study cohorts. We applied Lexis tabulation to the data and analyzed split records by using Poisson regression. Changes in cancer incidence in relation to treatment duration were examined by modeling the rate ratio (RR). After a median follow-up of 9 years, 53 cancer cases among users of anti-diabetic medication and 1,028 among non-users were diagnosed. No significant difference in cancer risk between users and non-users was observed after adjustment. The RR for all medication regardless of its duration was 1.01 [95% CI 0.75-1.33], and 1.37 [0.94-1.94] for period of 1-4 years. The results were similar for metformin, sulfonylurea, and insulin. This study demonstrates that evaluation of the variation in cancer risk in relation to treatment duration is of particular importance for enhancing the accuracy of conclusions on the link between exposure to anti-diabetic medication and cancer risk.

Background: In an analysis of the years 1976-1998, a 50% excess in cancer incidence was observed among residents in twelve blockhouses in Helsinki, Finland on a former dump area containing industrial and household waste., Objective: To assess cancer risk over a 13-year period 1999-2011 among residents formerly living in houses built on a dump area., Methods: All 1879 persons who ever lived in the former dump area were identified and the number of cancer cases in this population was obtained from the Finnish Cancer Registry., Results: After 5 years of residence at the dump site, the standardized incidence ratio of cancer (all sites combined) was 1·32 (95% CI: 0·94-1·79) in men and 0·53 (95% CI: 0·33-0·82) for women, in comparison with the general Helsinki population (1999-2011). No significant excess cancer risks were found., Conclusions: Residing on a former dump area was not found to result in an increased risk of cancer.

Objectives: Physical activity has been shown to decrease the risk of certain cancers. Objective of this study was to assess the effect of physical activity on cancer incidence in former male athletes in older age., Design: A cohort of 2448 elite male athletes and 1712 referents was followed-up for cancer incidence during 1986-2010 through the Finnish Cancer Registry., Methods: Standardised incidence ratios were calculated with the general male population as the reference. Self-reported questionnaire-based data on covariates were used in Cox regression analyses comparing the risk of cancer in athletes and referents., Results: The overall cancer incidence was lower in athletes than in the general population, standardised incidence ratio 0.89 (95% confidence interval 0.81-0.97). It was lowest among middle-distance runners (standardised incidence ratio 0.51, 95% confidence interval 0.22-1.01), long-distance runners (standardised incidence ratio 0.57, 95% confidence interval 0.35-0.88) and jumpers (standardised incidence ratio 0.60, 95% confidence interval 0.37-0.92). The standardised incidence ratio of lung cancer among athletes was 0.40 (95% confidence interval 0.27-0.55) and that of kidney cancer 0.23 (95% confidence interval 0.06-0.57). The hazard ratio for lung cancer between athletes and referents increased from the unadjusted ratio of 0.29 (95% confidence interval: 0.18-0.48) to 0.61 (95% confidence interval: 0.30-1.26) after adjustment for smoking status and pack-years of smoking., Conclusions: Former male elite athletes evidently have less cancer than men on the average. The lesser risk can be attributed to lifestyle factors, notably less frequent smoking among the athletes., (Copyright © 2013 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.)

Objectives: The association between celiac disease and malignancies is well recognized. In Finland, the prevalence of clinically diagnosed adult celiac disease is 0.6%. In this large, population-based cohort, we aimed at a realistic projection of the cancer risk., Methods: In the period 2002-2011, the register comprised 32,439 adult celiac patients. This was linked with the Finnish Cancer Registry, which covers over 98% of diagnosed malignancies. The standardized incidence ratio (SIR) was calculated for the malignancies, on the basis of incidence figures for the whole population. A time-stratified analysis was made in celiac patients diagnosed after 2004 (n=11,991). Lifestyle factors, including smoking habits and obesity, were not obtainable., Results: The overall incidence ratio of malignant diseases was not increased (SIR 0.94; 95% confidence intervals 0.89-0.98), but it was ≥5 years from the diagnosis of celiac disease (1.31, 1.04-1.63). The SIRs for non-Hodgkin lymphoma (NHL; 1.94; 1.62-2.29), small-intestinal cancer (4.29; 2.83-6.24), colon cancer (1.35; 1.13-1.58), and basal cell carcinoma of the skin (1.13; 1.03-1.22) were increased, whereas those for lung cancer (0.60; 0.48-0.74), pancreatic cancer (0.73; 0.53-0.97), bladder cancer (0.53; 0.35-0.77), renal cancer (0.72; 0.51-0.99), and breast cancer (0.70; 0.62-0.79) were decreased. SIR for NHL immediately after the diagnosis of celiac disease was 2.56 (1.37-4.38)., Conclusions: There was no increased SIR of cancer in the whole series, but SIR was increased after 5 years from the diagnosis of celiac disease. The risk of breast and lung cancers was decreased. The risk of small-intestinal cancer and NHL was increased, but to a lesser extent than previously described.

Objective: To examine the association between premenopausal use of the levonorgestrel-releasing intrauterine system and cancer incidence in Finland with a special focus on endometrial adenocarcinoma., Methods: All Finnish women aged 30-49 years using a levonorgestrel-releasing intrauterine system for treatment of menorrhagia in 1994-2007 (n=93,843) were identified from the National Reimbursement Registry and linked to the Finnish Cancer Registry data. The incidence of cancers in levonorgestrel-releasing intrauterine system users was compared with that in the general population., Results: A total of 2,781 cancer cases were detected in levonorgestrel-releasing intrauterine system users during the follow-up of 855,324 women-years. The standardized incidence ratio (observed-to-expected ratio) for endometrial adenocarcinoma was 0.50 (95% confidence interval [CI] 0.35-0.70; 34 observed compared with 68 expected cases) after the first levonorgestrel-releasing intrauterine system purchase and 0.25 (95% CI 0.05-0.73; three observed compared with 12 expected cases) after two purchases. The standardized incidence ratio for ovarian cancer was 0.60 (95% CI 0.45-0.76; 59 observed compared with 99 expected cases), for pancreatic cancer 0.50 (95% CI 0.28-0.81; 15 observed compared with 30 expected cases), and for lung cancer 0.68 (95% CI 0.49-0.91; 43 observed compared with 63 expected cases). The standardized incidence ratio for breast cancer among all levonorgestrel-releasing intrauterine system users was 1.19 (95% CI 1.13-1.25; 1,542 observed compared with 1,292 expected cases)., Conclusion: The levonorgestrel-releasing intrauterine system may have a protective effect against endometrial malignant transformation. Using the levonorgestrel-releasing intrauterine system for treatment of menorrhagia during reproductive years was associated with a lower incidence of endometrial, ovarian, pancreatic, and lung cancers than expected. Levonorgestrel-releasing intrauterine system use was associated with a higher than expected incidence of breast cancer., Level of Evidence: II.

The relation between body mass index (BMI) and risk of cancer incidence is controversial. Cancer incidence during 1972-2008 in relation to BMI was investigated in a prospective cohort of 54,725 Finns aged 24-74 years and free of cancer at enrollment. Over a mean follow-up of 20.6 years, 8,429 (15.4%) incident cancers were recorded, 4,208 (49.9%) from men. Both parametric and nonparametric approaches were used to evaluate the shape of the relationship between BMI and incidence of cancer. BMI had a linear positive association with incidence of cancers of the colon, liver, kidney, bladder and all sites combined in men, and of cancers of the stomach, colon, gallbladder and ovary in women, an inverse association with incidence of cancers of the lung in men and the lung and breast in women, a J-shaped association with incidence of all cancers combined in women. High BMI in women was associated with an increased overall cancer risk in never smokers but a reduced risk in smokers. Elevated BMI was associated with an increased risk of incidence of cancers of certain sites.

Objectives: Firefighters are potentially exposed to a wide range of known and suspected carcinogens through their work. The objectives of this study were to examine the patterns of cancer among Nordic firefighters, and to compare them with the results from previous studies., Methods: Data for this study were drawn from a linkage between the census data for 15 million people from the five Nordic countries and their cancer registries for the period 1961-2005. SIR analyses were conducted with the cancer incidence rates for the entire national study populations used as reference rates., Results: A total of 16 422 male firefighters were included in the final cohort. A moderate excess risk was seen for all cancer sites combined, (SIR=1.06, 95% CI 1.02 to 1.11). There were statistically significant excesses in the age category of 30-49 years in prostate cancer (SIR=2.59, 95% CI 1.34 to 4.52) and skin melanoma (SIR=1.62, 95% CI 1.14 to 2.23), while there was almost no excess in the older ages. By contrast, an increased risk, mainly in ages of 70 years and higher, was observed for non-melanoma skin cancer (SIR=1.40, 95% CI 1.10 to 1.76), multiple myeloma (SIR=1.69, 95% CI 1.08 to 2.51), adenocarcinoma of the lung (SIR=1.90, 95% CI 1.34 to 2.62), and mesothelioma (SIR=2.59, 95% CI 1.24 to 4.77). By contrast with earlier studies, the incidence of testicular cancer was decreased (SIR=0.51, 95% CI 0.23 to 0.98)., Conclusions: Some of these associations have been observed previously, and potential exposure to polycyclic aromatic hydrocarbons, asbestos and shift work involving disruption of circadian rhythms may partly explain these results.

Twenty-five years have passed since the Chernobyl accident, but its health consequences remain to be well established. Finland was one of the most heavily affected countries by the radioactive fallout outside the former Soviet Union. We analyzed the relation of the estimated external radiation exposure from the fallout to cancer incidence in Finland in 1988-2007. The study cohort comprised all ∼ 3.8 million Finns who had lived in the same dwelling for 12 months following the accident (May 1986-April 1987). Radiation exposure was estimated using data from an extensive mobile dose rate survey. Cancer incidence data were obtained for the cohort divided into four exposure categories (the lowest with the first-year committed dose <0.1 mSv and the highest ≥ 0.5 mSv) allowing for a latency of 5 years for leukemia and thyroid cancer, and 10 years for other cancers. Of the eight predefined cancer sites regarded as radiation-related from earlier studies, only colon cancer among women showed an association with exposure from fallout [excess rate ratio per increment in exposure category 0.06, 95% confidence interval (CI) 0.02-0.11]. No such effect was observed for men, or other cancer sites. Our analysis of a large cohort over two decades did not reveal an increase in cancer incidence following the Chernobyl accident, with the possible exception of colon cancer among women. The largely null findings are consistent with extrapolation from previous studies suggesting that the effect is likely to remain too small to be empirically detectable and of little public health impact.

Background: Commercial airline crew is one of the occupational groups with the highest exposures to ionising radiation. Crew members are also exposed to other physical risk factors and subject to potential disruption of circadian rhythms., Methods: This study analyses mortality in a pooled cohort of 93 771 crew members from 10 countries. The cohort was followed for a mean of 21.7 years (2.0 million person-years), during which 5508 deaths occurred., Results: The overall mortality was strongly reduced in male cockpit (SMR 0.56) and female cabin crews (SMR 0.73). The mortality from radiation-related cancers was also reduced in male cockpit crew (SMR 0.73), but not in female or male cabin crews (SMR 1.01 and 1.00, respectively). The mortality from female breast cancer (SMR 1.06), leukaemia and brain cancer was similar to that of the general population. The mortality from malignant melanoma was elevated, and significantly so in male cockpit crew (SMR 1.57). The mortality from cardiovascular diseases was strongly reduced (SMR 0.46). On the other hand, the mortality from aircraft accidents was exceedingly high (SMR 33.9), as was that from AIDS in male cabin crew (SMR 14.0)., Conclusions: This large study with highly complete follow-up shows a reduced overall mortality in male cockpit and female cabin crews, an increased mortality of aircraft accidents and an increased mortality in malignant skin melanoma in cockpit crew. Further analysis after longer follow-up is recommended.

Objective: To determine cancer incidence among Finnish women with 10 or more deliveries., Methods: Finnish women with at least 10 childbirths before December 31, 2010 (n=4,967) were identified from the Finnish Population Register and followed for cancer incidence through the Finnish Cancer Registry to the end of 2010. Cancer risks in this cohort were expressed as ratios between observed and expected numbers of cases (standardized incidence ratios), both drawn from the Finnish Cancer Registry, with 95% confidence intervals (CIs)., Results: Total cancer incidence was markedly lower than in the reference population (656 cases, standardized incidence ratio 0.76, 95% CI 0.73-0.79). There was clearly less breast (0.44, 0.35-0.53), ovarian (0.49, 0.28-0.80), endometrial (0.31, 0.17-0.44), and basal cell skin cancer (0.72, 0.60-0.85) than in the reference population. The incidence of thyroid cancer (2.33, 1.59-3.29), lip cancer (2.87, 1.05-6.24), and uterine sarcoma (3.41, 1.47-6.72) was markedly increased., Conclusion: Women with 10 or more deliveries show a decreased overall cancer incidence as a result of decreased risks of cancers of the ovary, endometrium, and breast and basal cell carcinoma of the skin. The increased risks were observed in thyroid cancer and some rare cancer types.