Introduction Although the rising worldwide incidence of thyroid cancer (TC) has been largely attributed to changes in diagnostic means, the full spectrum of contributing factors remains unknown. We present a comprehensive registry-based study evaluating the impact of occupational background on the risk of TC in the Nordic countries. Methods Data were from the Nordic Occupational Cancer (NOCCA) study from the Nordic countries from 1961 to 2005. Standardized incidence ratio (SIR) of TC in each occupational category was calculated using national incidence rates as reference. Results The NOCCA cohort includes 14.9 million people (7.5 million women (50.3%), 7.4 million men (49.7%)). In total, 23,241 TCs were recorded: 16,758 (71.9%) in women and 6483 in men. Increased SIRs were observed in female farmers (SIR 1.19; 95% CI 1.07-1.30) and male fishermen (1.32;1.06-1.62), military personnel (1.29; 0.99-1.66), and clerical workers (1.19; 1.05-1.35). Conclusion Our results suggest an association between certain occupational backgrounds and TC. These findings may help elucidate new risk factors for TC to enable targeted diagnosis and surveillance of individuals most at risk.
Evidence suggests that testicular cancer (TC) originates from germ cell neoplasia in situ arising during fetal development, implying that prenatal environmental exposures may influence disease risk. We investigated whether maternal place of residence during pregnancy is associated with regional variation in TC incidence. We conducted a nationwide cohort study including 1,342,996 men born in Finland between 1960 and 1999. Participants were followed from birth until diagnosis of TC, death, emigration, or the end of follow-up (2021). A total of 2976 TC cases were identified. Information on municipality of birth was used as a proxy for maternal residence during pregnancy. Incidence rates and cumulative incidence were estimated by birth cohort and age at diagnosis. To examine regional variation, cumulative TC incidence by birth cohort and municipality was modeled using Bayesian hierarchical binomial regression allowing incidence to vary across municipalities. TC incidence increased across birth cohorts, peaking among men born in 1975-1979 (16.8 per 100,000). Cumulative incidence rose in all municipalities, ranging from 67.9 to 132.5 per 100,000 among men born in 1960-1969 and from 283.2 to 327.6 among those born in 1980-1989. Marked geographic clustering was observed. Incidence was consistently elevated among men born in southwestern Finland and remained high throughout the study period. Over successive birth cohorts, an eastward shift in higher incidence was observed. Although direct cohort evidence linking specific environmental exposures to TC remains limited, these findings support the hypothesis that prenatal environmental factors contribute to the pathogenesis of TC and may partly explain regional differences in incidence.
BACKGROUND:Neurofibromatosis 1 (NF1) is a cancer predisposition syndrome caused by pathogenic variants of the NF1 gene. Here, we analyze the incidence and risk of cancer and especially the risk of multiple primary cancers in individuals with NF1. METHODS:The previously established Finnish NF1 cohort was extended to include 1,811 individuals with verified NF1 and followed up using the nationwide Finnish Cancer Registry for 30,612 person-years over 1987-2020. Standardized incidence ratios (SIRs) were used to analyze cancer incidence. RESULTS:A total of 296 first primary cancers occurred in individuals with NF1 during the follow-up, yielding an SIR of 4.92 (95% CI 4.38-5.52). The SIR was 4.30 (95% CI 3.27-5.54) for second primary cancers with 59 cancers observed. Therefore, the history of first primary cancer did not, in general, indicate altered risk for second primary cancer among individuals with NF1 (P=0.377). Overall, NF1 was associated with a steadily increasing cumulative risk for cancer throughout the lifetime. Women with NF1 had a 20.9% (95% CI 15.9-27.4%) lifetime risk for breast cancer with significantly increased incidence at ages <50 and ≥50 years (SIRs 4.90, 95% CI 2.99-7.56 and 2.67, 95% CI 1.76-3.89, respectively). CONCLUSION:The history of a prior cancer does not predict the overall future risk for cancer in NF1. Nevertheless, the estimates are consistent with some subpopulations having an increased risk for multiple cancers. Regarding breast cancer predisposition, the results confirm NF1 as a moderate-risk gene linked to increased incidence across all ages, i.e., not only in young women.
Background: Breast cancer survival in Finland is among the highest globally, with ten-year relative survival approaching 90% (or 5-year survival over 90%). Given the country’s universal healthcare system, this study aimed to describe the variation in five- and ten-year relative survival from breast cancer in Finland to identify potential regional disparities in outcomes. Materials and Methods: We performed a nationwide registry-based cohort study by using Finnish Cancer Registry (FCR) data for all female breast cancers diagnosed in 2000–2022. 5 and 10-year survival were compared across 23 welfare regions by estimating age-standardised Relative survival (RS) for each region. Results: Five-year RS improved from 88% in 2000–2004 to 92% by 2015–2019, and ten-year RS rose from 82% in 2000-2004 to 87% in 2010-2014. The overall median age at diagnosis was 63.4 years. In each period, a few regions had slightly lower or higher survival than the national average, but differences were small (<10 percentage points). No region showed a consistent survival disadvantage over time, indicating an absence of substantial regional disparities. Conclusion: Breast cancer survival in Finland showed no major regional gaps. All regions had comparably high and improving 5- and 10-year survival, suggesting that breast cancer care is delivered equitably across the country.
INTRODUCTION:It has been estimated that 2% to 8% of cancers in high-income countries are linked to carcinogenic exposures in workplaces. In Finland, employers are obliged by law to provide data annually on selected carcinogens and carcinogenic working processes to the Finnish Register of Employees Exposed to Carcinogens (ASA). In this study, we expand the follow-up period of a previous study on cancer incidence in exposed employees by 16 years and add estimates of cancer mortality. METHODS:The study population included all 142,204 workers registered in ASA from 1979 to 2018. For the cancer follow-up, the data were linked to the Finnish Cancer Registry. To compare the incidence and mortality with those of the Finnish general population, we estimated standardized incidence ratios (SIRs) and standardized mortality ratios. RESULTS:A total of 12,687 cancer cases and 3,640 cancer deaths were reported among ASA workers over time by the end of 2019. In the entire ASA cohort, the all-site cancer incidence was similar to the general population (SIR 0.98, 95% confidence interval [CI] 0.96 to 0.99). Persons exposed to asbestos showed an excess incidence of mesothelioma (SIR 1.80, CI 1.17 to 2.66) and small cell carcinoma of the lungs (SIR 1.32, CI 1.02 to 1.67). Exposure to hardwood dust (oak and beech) was associated with an increased incidence of nasal cancer (8.69, 1.05 to 31.4), specifically nasal adenocarcinoma (SIR 58.3, CI 7.06 to 211). Increased mortality was observed for exposure-cancer combinations that also showed increased cancer incidence. CONCLUSIONS:This study demonstrated the strongest confirmed associations between occupational exposures and cancer. The absence of many known exposure-cancer associations may point to low levels of exposure among workers registered in ASA or to small effect sizes of the agents investigated.
