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STUDY QUESTION Is there an association between premature ovarian insufficiency (POI) and severe autoimmune diseases before and after POI diagnosis? SUMMARY ANSWER Women with POI had at least one hospital-treated autoimmune disorder preceding POI diagnosis 2.6 times more often compared with matched female controls, and a 2- to 3-fold risk for these diseases for several years after POI diagnosis. WHAT IS KNOWN ALREADY It has been suggested that autoimmunity is an important factor in the pathogenesis of POI. Estimations of the prevalence of POI cases with autoimmune origin have ranged from 4% to 50%. STUDY DESIGN, SIZE, DURATION This population-based registry study included 3972 women diagnosed with spontaneous POI between 1988 and 2017 and 15 708 female population controls and used both case–control and cohort analysis. Autoimmune disease diagnoses were evaluated from childhood until the end of the year 2017. PARTICIPANTS/MATERIALS, SETTING, METHODS Women with POI were identified from the reimbursement registry of the Finnish Social Insurance Institution by their right to hormone replacement therapy (HRT). Four female population controls matched by age and municipality of residence were searched for each POI case to form a reference cohort. Women with a history of cancer or bilateral oophorectomy were excluded. Severe autoimmune disorder diagnoses for the years 1970–2017 were identified from the Hospital Discharge Registry. Odds ratios (ORs) with 95% confidence intervals (CI) were calculated using binary logistic regression for cases of having any, or one or more, specific autoimmune diseases preceding the index date (the date when reimbursement for HRT was granted for the POI) among women with POI as compared to controls. Standardized incidence ratios (SIR) with 95% CIs for getting diagnosed with an autoimmune disease after the index date in 3-year follow-up periods among women with POI (who did not have these diseases prior to the index date) were also calculated. The expected numbers of autoimmune disease cases were based on the incidence of first-onset severe autoimmune disease among the controls. MAIN RESULTS AND THE ROLE OF CHANCE The prevalence of having at least one severe autoimmune disease in women with POI was 5.6% (n = 233), with an OR of 2.6 (95% CI 2.2, 3.1) when compared to population controls. Women with POI had an increased prevalence of several specific autoimmune diseases prior to the index date compared to controls: polyglandular autoimmune diseases (OR 25.8, 95% CI 9.0, 74.1), Addison's disease (OR 22.9, 95% CI 7.9, 66.1), vasculitis (OR 10.2, 95% 4.3, 24.5), systemic lupus erythematosus (OR 6.3 95% CI 4.2, 20.3), rheumatoid arthritis (OR 2.3, 95% CI 1.7, 3.2), sarcoidosis (OR 2.3, 95% CI 1.2, 4.5), inflammatory bowel diseases (OR 2.2, 95% CI 1.5, 3.3), and hyperthyroidism (OR 1.9, 95% CI 1.2, 3.1); whereas the prevalence of diabetes type 1 and ankylosing spondylitis did not differ between the women with POI and the reference cohort. The SIRs for being diagnosed for the first time with a severe autoimmune disease after POI diagnosis was 2.8 (95% CI 2.3, 3.4), during the first three years after POI diagnosis, decreasing gradually to 1.3 (1.1, 1.6) after 12 years. LIMITATIONS, REASONS FOR CAUTION This study only included autoimmune disorders diagnosed in specialized health care; hence, the overall prevalence of autoimmune disorders in women with POI may be higher. WIDER IMPLICATIONS OF THE FINDINGS Severe autoimmune diseases have a strong association with POI, suggesting that immunological mechanisms play a pivotal role in POI. Future studies should focus on specific autoimmune mechanisms behind POI, from both preventive and curative perspectives. STUDY FUNDING/COMPETING INTEREST(S) This work was financially supported by Oulu University Hospital. S.M.S. received grants from the Finnish Menopause Society, the Finnish Medical Foundation, and the Juho Vainio Foundation. H.S. received grants from the Finnish Menopause Society, the Oulu Medical Research Foundation, the Finnish Research Foundation of Gynecology and Obstetrics, UniOGS graduate school, The Finnish Medical Society Duodecim, Orion Research Foundation, and the University of Oulu Scholarship Fund. M.-M.O. received a grant from the Sakari Alhopuro Foundation and the Finnish Diabetes Research Foundation. None of the funders had any involvement in the study design or its execution or reporting. The authors do not have any competing interests to report. TRIAL REGISTRATION NUMBER N/A. [ABSTRACT FROM AUTHOR]

This article presents the findings of a population-based case-control study on risk factors for lichen planus (LP) in women. The study found that certain conditions such as hepatitis C, oral candidiasis, periodontitis, Sjögren's syndrome, and vitiligo increased the odds of LP, while autoimmune diseases like systemic lupus erythematosus, rheumatoid arthritis, and Graves' disease decreased the odds. Cardiometabolic and psychiatric conditions were associated with reduced odds of LP. The study emphasized the importance of considering the temporal order of diagnoses when examining comorbidities and called for further research on the pathogenetic process of LP and its associated conditions. The study did not find any significant association between LP and urbanicity level or socioeconomic status. [Extracted from the article]

We examined the overall and site-specific cancer mortality disparities among first-generation - separately in adults (G1) and children (G1.5) at immigration - and second-generation (G2) immigrants and their countries of origin using population-based registries in Sweden, encompassing over 8.5 million individuals aged 20 and above residing in Sweden since 1990, with follow-up until December 31, 2023. Cox proportional hazard models were fitted, stratified by gender, to estimate hazard ratios and 95% confidence intervals compared to natives. Mortality rates for most cancers transitioned from lower in G1 towards the rate of natives in G2. However, elevated mortality rates were sustained across generations for liver cancer in males and stomach cancer in females. Among G2, mortality from lymphohematopoietic cancers in males, and lung and cervix uteri cancers in females were elevated - by 10%, 9%, and 17% respectively compared to natives. Country of origin analyses revealed substantial disparities. For instance, G2 females with Nordic parental origin had a 13% higher risk of death from lung cancer, while those with non-Western parental origin had a 54% lower risk as compared to natives. These findings suggest a generational and arrival-age dynamics of cancer mortality and highlight target groups for cancer prevention and control among immigrants., (© The Author(s) 2024. Published by Oxford University Press on behalf of the Johns Hopkins Bloomberg School of Public Health.)

Introduction: We report head-to-head comparison of the bivalent and quadrivalent HPV vaccine efficacies against immediate precursors of cervical cancer from 15 years' country-wide cancer registry follow-up of phase III trial cohorts and an age-aligned cohort of unvaccinated women., Methods: These individually and/or clusterrandomized cohorts of HPV6/11/16/18- and HPV16/18-vaccinated and unvaccinated women were enrolled, respectively, in 2002, 2004, and 2003/2005. The trial cohorts comprised initially 16- to 17-year-old HPV6/11/16/18-vaccinated FUTURE II (NCT00092534) participants (866) and HPV16/18-vaccinated PATRICIA (NCT00122681) and 012 trial (NCT00169494) participants (2,465), and 16,526 initially 16- to 19-year-old unvaccinated controls. After active 4-year clinical follow-up, passive, country-wide Finnish Cancer Registry (FCR) follow-up for cervical intraepithelial neoplasia grade 3 (CIN3) and adenocarcinoma in situ (AIS) was based on consented use of unique personal identifiers and started 6 months after the end of the FUTURE II and PATRICIA trials in 2007 and 2009, and ended at the end of 2019. The follow-up with altogether 229,020 follow-up years was age-aligned to ensure that similarly aged cohorts were passively followed up for 15 years post=vaccination for the intention-to-treat analyses of vaccine efficacy., Results: Overall, we identified 5 and 16 CIN3 (no AIS) cases in the HPV6/11/16/18 and HPV16/18 cohorts, respectively, during the FCR-based follow-up. In the unvaccinated cohort, we identified 281 CIN3 cases, 20 AIS cases, and 13 cases with invasive cervical cancer. Vaccine efficacies against CIN3+ were 68.4% and 64.5% for the quadrivalent and the bivalent vaccines, respectively, with overlapping confidence intervals., Discussion: Long-term follow-up of randomized, initially adolescent HPV-vaccinated and unvaccinated cohorts shows, in this head-to-head setting, that the bivalent and quadrivalent HPV vaccines are equally effective against immediate precursors of cervical cancer., Competing Interests: DA, JD, ML, and JPaa have received grants for their HPV vaccination studies from Merck&Co. Inc. DA, JD, ML, and JPaa and GSK Biologicals DA, ML, JPaa. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Lehtinen, Gray, Luostarinen, Eriksson, Apter, Bly, Harjula, Heikkilä, Hokkanen, Kuortti, Nieminen, Nummela, Paavonen, Palmroth, Petäjä, Pimenoff, Pukkala and Dillner.)

Background and Purpose: Changes in treatment approaches, characterised by the shift from laryngectomy to a focus on organ-preserving methods may have potentially resulted in lower survival. We aim to identify differences in survival trends for laryngeal cancer (LC) in the Nordic countries over a period of 50 years, and discuss the potential impact of factors such as changes in treatment protocols., Materials and Methods: Five-year relative survival (RS) data from 1972 to 2021 were obtained from the NORDCAN database 2.0 which included 33,692 LC cases, of which 85% were diagnosed among men. In the NORDCAN database, the age-standardised RS is calculated using the Pohar Perme estimator with individual International Cancer Survival Standards weights. Joinpoint regression models were used to assess potential shifts in trend over the years in RS., Results: While Denmark and Norway demonstrated an increasing trend in 5-year RS from 1972 to 2021, in Finland and Sweden, the 5-year RS among men remained static, without any discernible significant trend. Over the 30-year period from 1992-1996 to 2017-2021, RS improved by 9, 4, 13, and 2 percentage points in Denmark, Finland, Norway, and Sweden, respectively. Among women in Sweden, a linear negative trend was observed, noticeable as a 16 percentage-point decline in 5-year RS from the earliest to the latest period., Interpretation: The underlying causes for the differences in survival trends remain unclear. Besides differences in treatment protocols, several other factors can affect RS making the interpretation of RS trends challenging.

Objective: Despite the implementation of the WHO Framework Convention on Tobacco Control (FCTC) program in Iran, the regulation of second-hand smoke (SHS) exposure-an often-overlooked hazard-, still requires improvement. We employed a multi-center case-control study to investigate the association between exposure to secondhand smoke (SHS) from various tobacco products (cigarettes, water-pipes, pipes, and chopogh), opium use, and the risk of lung cancer., Method: We included 627 lung cancer cases and 3477 controls. Exposure to SHS tobacco and SHS opium was collected through a questionnaire. We used mixed-model logistic regressions to estimate odds ratios (ORs) and 95% confidence intervals (CI)., Result: Among the overall population exposed to second-hand tobacco smoke (SHTS), the odds ratio (OR) compared to those never exposed was 1.35 (95% CI: 1.08-1.71). Never smokers who were ever exposed to second-hand tobacco smoke (SHTS) had 1.69-fold risk of lung cancer compared to those who were never exposed (95% CI: 1.13-2.52). Exposure to SHTS between 2-3 per day (OR = 2.27, 95% CI: 1.13-4.53) and more than three hours per day (OR = 2.29, 95% CI: 1.20-4.37) can increase the risk of lung cancer compared with the no exposure group (P-trend <0.01). We did not observe any association between exposure to second-hand opium smoke (SHOS) and the risk of lung cancer, either in the overall population or among never-smokers., Conclusion: Our study estimates the impact of second-hand tobacco smoke (SHTS) on lung cancer risk in both the overall population and never-smokers. Additional studies are required to evaluate the association between exposure to second-hand smoke from opium and other type of tobacco, including water-pipe and the risk of lung cancer., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2024 Lotfi et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

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.)

Background: The impact of societal factors on the occurrence of head and neck cancers (HNCs) remains understudied, especially in the Nordic countries., Methods: To quantify the association between socio-economic status (SES) and the occurrence of HNCs, this cohort study uses data from the Nordic Occupational Cancer project that combine occupational and cancer registry data from 1961 to 2005 of 14.9 million individuals aged between 30 and 64 years. Occupational categories were combined into seven socio-economic categories. Standardized incidence ratio (SIR) analyses were conducted with the cancer incidence rates for the entire national study populations used as reference rates., Results: Altogether, 83 997 HNCs-72% in men and 28% in women-were recorded. Among men, a gradient of risk associated with SES was observed for cancers of the tongue, other oral cavity subsites, pharynx, oropharynx and larynx in groups with lower SES. Managers showed decreased SIRs of 0.50 to -0.90 also for cancers of the lip, tongue, other oral cavity subsites, oropharynx, nasopharynx, nose and larynx. In contrast, excess risks of tongue, other oral cavity subsites, pharyngeal, oropharyngeal and laryngeal cancers were observed among clerical (SIRs 1.05-1.16), skilled workers (1.04-1.14), unskilled workers (1.16-1.26) and economically inactive men (1.38-1.87). Among women, no risk gradient similar to that in men was revealed., Conclusions: The current study underscores the influence of SES on the incidence of HNCs and highlights the need for targeted interventions, including tobacco and alcohol control policies, and improved access to healthcare services, particularly for socio-economically disadvantaged populations., (© The Author(s) 2024; all rights reserved. Published by Oxford University Press on behalf of the International Epidemiological Association.)

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: Almost 200,000 tongue cancers were diagnosed worldwide in 2020. The aim of this study was to describe occupational risk variation in this malignancy., Methods: The data are based on the Nordic Occupational Cancer (NOCCA) study containing 14.9 million people from the Nordic countries with 9020 tongue cancers diagnosed during 1961-2005. The standardized incidence ratio (SIR) of tongue cancer in each occupational category was calculated using national incidence rates as the reference., Results: Among men, the incidence was statistically significantly elevated in waiters (SIR 4.36, 95% confidence interval (CI) 3.13--5.92), beverage workers (SIR 3.42, 95% CI 2.02-5.40), cooks and stewards (SIR 2.55, 95% CI 1.82-3.48), seamen (SIR 1.66, 95% CI 1.36-2.00), journalists (SIR 1.85, 95% CI 1.18-2.75), artistic workers (SIR 2.05, 95% CI 1.54-2.66), hairdressers (SIR 2.17, 95% CI 1.39-3.22), and economically inactive persons (SIR 1.57, 95% CI 1.42-1.73). Among women, the SIR was statistically significantly elevated only in waitresses (SIR 1.39, 95% CI 1.05-1.81). Statistically significant SIRs ≤ 0.63 were observed in male farmers, gardeners, forestry workers and teachers, and in female launderers., Conclusions: These findings may be related to consumption of alcohol and tobacco, but the effect of carcinogenic exposure from work cannot be excluded., (© 2024. The Author(s).)

Genome-wide association studies (GWAS) have identified more than 200 common genetic variants independently associated with colorectal cancer (CRC) risk, but the causal variants and target genes are mostly unknown. We sought to fine-map all known CRC risk loci using GWAS data from 100,204 cases and 154,587 controls of East Asian and European ancestry. Our stepwise conditional analyses revealed 238 independent association signals of CRC risk, each with a set of credible causal variants (CCVs), of which 28 signals had a single CCV. Our cis-eQTL/mQTL and colocalization analyses using colorectal tissue-specific transcriptome and methylome data separately from 1299 and 321 individuals, along with functional genomic investigation, uncovered 136 putative CRC susceptibility genes, including 56 genes not previously reported. Analyses of single-cell RNA-seq data from colorectal tissues revealed 17 putative CRC susceptibility genes with distinct expression patterns in specific cell types. Analyses of whole exome sequencing data provided additional support for several target genes identified in this study as CRC susceptibility genes. Enrichment analyses of the 136 genes uncover pathways not previously linked to CRC risk. Our study substantially expanded association signals for CRC and provided additional insight into the biological mechanisms underlying CRC development., (© 2024. The Author(s).)

Narrow-band TL-01 ultraviolet B phototherapy (TL-01) is an effective and widely used treatment for many skin diseases. The purpose of the investigation was to assess the risk of skin cancers in patients treated with TL-01 phototherapy who have not received any other phototherapy modalities. This cohort study included 4,815 TL-01 treated patients in Finland with psoriasis or atopic dermatitis. Clinical information was collected from the hospital records and linked with Finnish Cancer Registry data. The follow-up started from the first TL-01 treatment and the mean follow-up time was 8.4 years. Standardized incidence ratios were calculated for basal cell carcinoma, cutaneous melanoma, and squamous cell carcinoma. The standardized incidence ratio for basal cell carcinoma was 2.5 (95% confidence interval 1.8-3.5), for cutaneous melanoma 4.0 (95% confidence interval 2.1-6.8) and for squamous cell carcinoma 3.7 (95% confidence interval 1.7-7.0). For basal cell carcinoma and squamous cell carcinoma, the standardized incidence ratios remained similar during the whole follow-up time while the standardized incidence ratio for cutaneous melanoma was markedly higher during the first 5 years of follow-up. In conclusion, an increased incidence of skin cancers was observed among TL-01 treated patients. It should be confirmed in the future whether the skin cancer risk of TL-01 phototherapy will remain high in a longer follow-up.

Background: Limited data exist for the association between bladder cancers and waterpipe smoking, an emerging global public health concern., Methods: We used the IROPICAN database in Iran and used multivariable logistic regression, adjusting for cigarette smoking, opium use, and other confounding factors. In addition, we studied the association between exclusive waterpipe smoking and bladder cancer., Results: We analyzed 717 cases and 3,477 controls and a subset of 215 patients and 2,145 controls who did not use opium or cigarettes. Although the OR adjusted for opium, cigarettes, and other tobacco products was 0.92 [95% confidence interval (CI), 0.69-1.20], we observed a statistically significant elevated risk in exclusive waterpipe smokers (OR = 1.78; 95% CI, 1.16-2.72) compared with non-users of opium or any tobacco. Associations were strongest for smoking more than two heads/day (OR = 2.25; 95% CI, 1.21-4.18) and for initiating waterpipe smoking at an age less than 20 (OR = 2.73; 95% CI, 1.11-6.72). The OR for urothelial bladder cancer was higher in ex-smokers (OR = 2.35; 95% CI, 1.24-4.42) than in current smokers (OR = 1.52; 95% CI, 0.72-3.15). All observed associations were consistently higher for urothelial histology., Conclusions: Waterpipe smoking may be associated with an increased risk of bladder cancer, notably among individuals who are not exposed to cigarette smoking and opium., Impact: The study provides compelling evidence that waterpipe smoking is a confirmed human carcinogen, demanding action from policymakers. See related In the Spotlight, p. 461., (©2024 The Authors; Published by the American Association for Cancer Research.)

Objectives: Lichen sclerosus (LS) is an inflammatory skin disease probably arising from an interplay of genetics, local irritation, and autoimmune processes. We identified potential risk factors for the disease using data from nationwide Finnish registries., Methods: We identified all women diagnosed with LS within specialized health care during 1998-2016 (n = 10,692) and selected 3 age-matched population control women for each case. We calculated odds ratios (ORs) for possible risk factors using conditional logistic regression., Results: Dermatological autoimmune conditions were strongly associated with LS (OR = 15.1, 95% confidence interval [CI] = 13.6-16.7 for morphea; OR = 10.3, 95% CI = 5.02-19.0 for lichen planus; OR = 6.86, 95% CI = 5.65-8.33 for alopecia; OR = 2.20, 95% CI = 1.88-2.56 for vitiligo). A diagnosis of Crohn or celiac disease increased the odds of LS (OR = 1.80, 95% CI = 1.71-1.89; OR = 1.49, 95% CI = 1.28-1.73, respectively) as did urge and stress incontinence (OR = 1.79, 95% CI = 1.71-1.87; OR = 1.28, 95% CI = 1.22-1.35, respectively).The odds of LS were lower in women after a diagnosis of type 1 diabetes (OR = 0.43, 95% CI = 0.41-0.45), coronary artery disease (OR = 0.41, 95% CI = 0.38-0.43), and rheumatoid arthritis (OR = 0.38, 95% CI = 0.36-0.41).Parous women had higher odds of LS (OR = 1.11, 95% CI = 1.04-1.17) than nulliparous ones, but increasing number of births decreased the risk. Lichen sclerosus was not associated with socioeconomic status nor the urbanicity level of the place of residence., Conclusions: Certain autoimmune diseases and urinary incontinence were associated with LS., Competing Interests: O.H. serves occasionally on scientific advisory boards organized by Bayer AG and Gedeon-Richter, and has lectured at educational events organized by these companies. The other authors have declared they have no conflicts of interest., (Copyright © 2024 The Author(s). Published by Wolters Kluwer Health, Inc. on behalf of the ASCCP.)

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).)