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Flavie Perrier,1 Reza Ghiasvand,2,3 Simon Lergenmuller,1 Trude E Robsahm,3 Adele C Green,4,5 Kristin B Borch,6 Torkjel M Sandanger,6 Elisabete Weiderpass,7 Corina S Rueegg,2 Marit B Veierød1 1Oslo Centre for Biostatistics and Epidemiology, Department of Biostatistics, Institute of Basic Medical Sciences, University of Oslo, Oslo, Norway; 2Oslo Centre for Biostatistics and Epidemiology, Oslo University Hospital, Oslo, Norway; 3Cancer Registry of Norway, Institute of Population-Based Cancer Research, Oslo, Norway; 4QIMR Berghofer Medical Research Institute, Brisbane, QLD, Australia; 5Cancer Research UK Manchester and Faculty of Biology, Medicine and Health, University of Manchester, Manchester, UK; 6Department of Community Medicine, Faculty of Health Sciences, UiT The Arctic University of Norway, Tromsø, Norway; 7International Agency for Research on Cancer, Lyon, FranceCorrespondence: Flavie Perrier, Oslo Centre for Biostatistics and Epidemiology, Department of Biostatistics, Institute of Basic Medical Sciences, University of Oslo, PO Box 1122, Blindern, Oslo, N-0317, Norway, Email flavie.perrier@medisin.uio.noPurpose: Physical activity (PA) is a cornerstone in disease prevention and varies throughout life. A pooled analysis of cohort studies and a meta-analysis of cohort studies found positive associations between PA and melanoma risk. However, previous studies focused on PA at specific ages and often lacked information on ultraviolet radiation (UVR) exposure. Using the population-based Norwegian Women and Cancer (NOWAC) cohort, including information on PA and UVR exposure, we estimated life-course PA trajectories from adolescence to adulthood and their associations with melanoma.Methods: Total PA across different domains (recreation, occupation, transport, household) was reported for ages 14 and 30 years, and when responding to the questionnaire (31– 76 years) using a 10-point scale, validated to rank PA levels in Norwegian females. We estimated life-course PA trajectories using a latent class mixed model in 152,248 women divided into three subcohorts depending on age at questionnaire completion: 31– 39 (n = 27,098), 40– 49 (n = 52,515) and ≥ 50 years (n = 72,635). The unique 11-digit identity number of Norwegian citizens was used to link NOWAC to the Cancer Registry of Norway for information on cancer diagnoses, emigration and death. Associations between PA trajectories and melanoma risk were estimated in each subcohort using multivariable Cox regression.Results: Five classes of individual life-course PA trajectories were identified in subcohort 31– 39 years (low, moderate, high, decreasing, increasing PA) and four in subcohorts 40– 49 and ≥ 50 years (low, moderate, high, decreasing PA). No significant association was found between life-course PA trajectories and melanoma risk in any subcohort. Hazard ratios (95% confidence intervals) for the high versus moderate trajectory were 0.92 (0.66– 1.29), 1.15 (0.97– 1.37) and 0.90 (0.78– 1.05) for subcohorts 31– 39, 40– 49 and ≥ 50 years, respectively.Conclusion: Our results do not support a positive association between PA and melanoma risk found in previous studies, which is important for public health guidelines promoting regular PA.Keywords: physical activity, cutaneous melanoma, trajectory, cohort, women, Norway

Helga H Hektoen,1 Randi E Gislefoss,1 Jo S Stenehjem,1 Hilde Langseth,1 Karol Axcrona,2 Alison M Mondul,3 Trude E Robsahm,1 Bettina K Andreassen1 1Department of Research, Cancer Registry of Norway, Oslo, Norway; 2Department of Urology, Akershus University Hospital, Lørenskog, Norway; 3Department of Epidemiology, University of Michigan School of Public Health, Ann Arbor, MI, USACorrespondence: Helga H Hektoen Ullernchausseen 64, Oslo, 0379, NorwayTel +47 22 92 89 21Email Helga.helseth.hektoen@kreftregisteret.noPurpose: Circulating 25-hydroxyvitamin D (25(OH)D) is inversely associated with overall cancer mortality and selected cancers, while for urothelial bladder cancer (BC) this relationship is unclear. We aimed to examine the association between 25(OH)D and BC mortality.Materials and Methods: We used prediagnostic serum from 378 BC cases within the population-based Janus Cohort. Cox regression models estimated hazard ratios (HRs), with 95% confidence intervals (CIs), for the association between 25(OH)D and BC-specific and all-cause mortality. Restricted cubic splines were assessed to examine non-linear risk associations. Analyses were stratified by tumor invasiveness (non-muscle invasive BC (NMIBC) and muscle invasive BC (MIBC)). Additionally, the association between 25(OH)D and all-cause mortality was assessed for 378 cancer-free matched controls.Results: 25(OH)D deficiency (< 50 nmol/L) was associated with higher BC-specific mortality (HR 1.87, 95% CI 1.10– 3.20), when compared with insufficient levels (50– 74 nmol/L). Stratification by tumor invasiveness revealed that this result was evident for NMIBC only, both with respect to BC-specific mortality (HR 2.84, 95% CI 1.14– 7.12) and all-cause mortality (HR 1.97, 95% CI 1.06– 3.65). No association between 25(OH)D levels and all-cause mortality was found in cancer-free controls.Conclusion: 25(OH)D deficiency (< 50 nmol/L) prior to a BC diagnosis was associated with increased risk of BC-specific mortality, when compared to insufficient levels (50– 74 nmol/L). The results were evident among NMIBC patients only, suggesting a more critical role of vitamin D deficiency in an early stage of the disease.Keywords: cancer, vitamin D, mortality, cancer death, prospective study

Leon Alexander Mclaren Berge,1– 3 Bettina Kulle Andreassen,1 Jo Steinson Stenehjem,1,2,4 Trond Heir,5,6 Øystein Karlstad,7 Asta Juzeniene,8 Reza Ghiasvand,1,9 Inger Kristin Larsen,10 Adele C Green,11,12 Marit Bragelien Veierød,2 Trude Eid Robsahm1,3 1Department of Research, Cancer Registry of Norway, Oslo, Norway; 2Oslo Centre for Biostatistics and Epidemiology, Department of Biostatistics, Institute of Basic Medical Sciences, University of Oslo, Oslo, Norway; 3Institute for Cancer Research, Oslo University Hospital, Oslo, Norway; 4Division of Emergencies and Critical Care, Oslo University Hospital, Oslo, Norway; 5Institute of Clinical Medicine, Faculty of Medicine, University of Oslo, Oslo, Norway; 6Oslo Ischemia Study, Oslo University Hospital, Oslo, Norway; 7Department of Chronic Diseases and Ageing, Norwegian Institute of Public Health, Oslo, Norway; 8Department of Radiation Biology, Institute for Cancer Research, Oslo University Hospital, Oslo, Norway; 9Oslo Centre for Biostatistics and Epidemiology, Oslo University Hospital, Oslo, Norway; 10Department of Registration, Cancer Registry of Norway, Oslo, Norway; 11Population Health Department, QIMR Berghofer Medical Research Institute, Brisbane, Australia; 12Molecular Oncology Unit, CRUK Manchester Institute, University of Manchester, Manchester, UKCorrespondence: Leon Alexander Mclaren BergeCancer Registry of Norway, Majorstuen, Oslo N-0304, NorwayTel +47 99605034Email Leon.Berge@kreftregisteret.noPurpose: Cutaneous melanoma is among the fastest growing malignancies in Norway and ultraviolet radiation (UVR) exposure is the primary environmental risk factor. Immunomodulating drugs can increase skin photosensitivity and suppress immune responses, and by such mechanisms influence melanoma risk. We, therefore, aimed to examine the associations between use of immunomodulating drugs and melanoma risk, at a nationwide population level.Patients and Methods: In the Cancer Registry of Norway, we identified all cases aged 18– 85 with a first primary cutaneous melanoma diagnosed in 2007– 2015 (n=12,106). These were matched to population controls from the Norwegian National Registry 1:10 (n=118,564), on sex and year of birth using risk set sampling. Information on prescribed drugs (2004– 2015) was obtained by linkage to the Norwegian Prescription Database (NorPD). Conditional logistic regression was used to estimate rate ratios (RRs) and 95% confidence intervals (CIs) for associations between use of immunomodulating drugs (immunosuppressants and corticosteroids) and melanoma risk, adjusted for ambient UVR and other drug use.Results: Compared with ≤ 1 prescription, use of ≥ 8 prescriptions of immunosuppressants was associated with increased risk of melanoma (RR 1.50, 95% CI 1.27, 1.77). Similar associations were found for subgroups of immunosuppressants: drugs typically prescribed to organ transplant recipients (OTRs) (RR 2.02, 95% CI 1.35, 3.03) and methotrexate (RR 1.27, 95% CI 1.04, 1.55). Similar results were found for high levels of cumulative doses and across all histological subtypes. Use of corticosteroids was not associated with melanoma risk.Conclusion: We found a positive association between use of immunosuppressants and melanoma risk, with the highest risk seen for drugs prescribed to OTRs. Knowledge about this risk increase is important for physicians and users of these drugs, for intensified surveillance, awareness and cautious sun exposure.Keywords: immunosuppressants, corticosteroids, melanoma, prescription drugs, pharmacoepidemiology, registry-based

Leon Alexander Mclaren Berge, 1, 2 Bettina Kulle Andreassen, 1 Jo S Stenehjem, 1–3 Trond Heir, 4, 5 Kari Furu, 6 Asta Juzeniene, 7 Ingrid Roscher, 8 Inger Kristin Larsen, 9 Adele C Green, 10, 11 Marit B Veierød, 2 Trude E Robsahm 1 1Department of Research, Cancer Registry of Norway, Oslo, Norway; 2Oslo Centre for Biostatistics and Epidemiology, Department of Biostatistics, Institute of Basic Medical Sciences, University of Oslo, Oslo, Norway; 3Division of Emergencies and Critical Care, Oslo University Hospital, Oslo, Norway; 4Institute of Clinical Medicine, Faculty of Medicine, University of Oslo, Oslo, Norway; 5Oslo Ischemia Study, Oslo University Hospital, Oslo, Norway; 6Department of Chronic Diseases and Ageing, Norwegian Institute of Public Health, Oslo, Norway; 7Department of Radiation Biology, Institute for Cancer Research, Oslo University Hospital, Oslo, Norway; 8Department of Rheumatology, Dermatology and Infectious Diseases, Oslo University Hospital, Oslo, Norway; 9Department of Registration, Cancer Registry of Norway, Oslo, Norway; 10QIMR Berghofer Medical Research Institute, Brisbane, Australia; 11CRUK Manchester Institute, University of Manchester, Manchester, UKCorrespondence: Leon Alexander Mclaren BergeCancer Registry of Norway, P.O. Box 5313 Majorstuen, Oslo N-0304, NorwayTel +47 99605034Email Leon.Berge@kreftregisteret.noPurpose: Melanoma is the cancer with the most rapidly rising incidence rate in Norway. Although exposure to ultraviolet radiation (UVR) is the major environmental risk factor, other factors may also contribute. Antidepressants have cancer inhibiting and promoting side effects, and their prescription rates have increased in parallel with melanoma incidence. Thus, we aimed to prospectively examine the association between use of antidepressants and melanoma by using nation-wide data from the Cancer Registry of Norway, the National Registry, the Norwegian Prescription Database and the Medical Birth Registry of Norway.Patient and Methods: All cases aged 18– 85 with a primary cutaneous invasive melanoma diagnosed during 2007– 2015 (n=12,099) were matched to population controls 1:10 (n=118,467) by sex and year of birth using risk-set sampling. We obtained information on prescribed antidepressants and other potentially confounding drug use (2004– 2015). Conditional logistic regression was used to estimate adjusted rate ratios (RRs) and 95% confidence intervals (CIs) for the association between overall and class-specific use of antidepressants and incident melanoma.Results: Compared with ≤ 1 prescription, ≥ 8 prescriptions of antidepressants overall were negatively associated with melanoma (RR 0.81 CI 0.75– 0.87). Class-specific analyses showed decreased RRs for selective serotonin reuptake inhibitors (RR 0.82 CI 0.73– 0.93) and mixed antidepressants (RR 0.77 CI 0.69– 0.86). The negative association was found for both sexes, age ≥ 50 years, residential regions with medium and highest ambient UVR exposure, all histological subtypes, trunk, upper and lower limb sites and local disease.Conclusion: Use of antidepressants was associated with decreased risk of melanoma. There are at least two possible explanations for our results; cancer-inhibiting actions induced by the drug and less UVR exposure among the most frequent users of antidepressants.Keywords: antidepressants, melanoma, prescription drugs, pharmacoepidemiology, registry-based

Ragnhild S Falk,1 Trond Heir,2,3 Trude E Robsahm,4 Steinar Tretli,4 Leiv Sandvik,1 Jan E Erikssen,2 Jan E Paulsen5 1Oslo Centre for Biostatistics and Epidemiology, Oslo University Hospital, Oslo, Norway; 2Oslo Ischemia study, Oslo University Hospital, Oslo, Norway; 3Institute of Clinical Medicine, Faculty of Medicine, University of Oslo, Oslo, Norway; 4Department of Research, Cancer Registry of Norway, Oslo, Norway; 5Department of Food Safety and Infection Biology, Norwegian University of Life Sciences, Oslo, NorwayCorrespondence: Ragnhild S FalkOslo Centre for Biostatistics and Epidemiology, Oslo University Hospital, Pb 4950 Nydalen, Oslo 0424, NorwayTel +47 23 06 60 13Email rs@ous-hf.noPurpose: To examine whether serum levels of potassium and sodium were associated with long-term cancer risk in initially healthy men.Patients and Methods: A cohort of 1994 initially healthy men with no use of medication, aged 40–59 years, was followed for cancer during 40 years of follow-up. Associations between fasting electrolyte levels and cancer risk were assessed with incidence rates and Cox proportional hazards models.Results: Potassium, but not sodium, was linearly associated with cancer risk. This association remained significant after adjustment of several potential confounding factors, and also after excluding the first 10 years of follow-up. The age-adjusted risk of all-site cancer increased with 16% for each SD increase in potassium level. Men with hyperkalemia showed an incidence rate that was 40% higher than for men with normal potassium levels.Conclusion: Fasting serum potassium level in healthy men was positively associated with long-term cancer risk. Potassium or potassium ion channels may have a role in cell proliferation or differentiation. These findings might imply future cancer strategies for targeting individuals with high serum potassium levels.Keywords: cancer incidence, cell proliferation, electrolyte levels, epidemiology, prospective cohort study

Trude Eid Robsahm,1 Steinar Tretli,1 Peter Abusdal Torjesen,2 Ronnie Babigumira,1 Gary G Schwartz31The Cancer Registry of Norway, Institute of Population-based Cancer Research, Oslo, Norway; 2The Hormone Laboratory, Department of Endocrinology, Oslo University Hospital Health Authority, Oslo, Norway; 3Department of Population Health, University of North Dakota School of Medicine and Health Sciences, Grand Forks, ND, USAPurpose: Circulating 25-hydroxyvitamin D (25-OHD) levels have been inversely associated with cancer death, but the nature of this relationship is unclear. We investigated this association using repeated measurements of serum 25-OHD.Patients and methods: Pre-diagnostic serum samples were collected in population health surveys in Norway (1973–2004). Participants who subsequently developed cancer (1984–2004) provided a second serum sample at the time of cancer diagnosis. Samples were stored in the Janus Serum Bank. Repeated samples existed from 202 breast cancers, 193 lung cancers, 124 lymphomas, and 37 colon cancers. Serum 25-OHD was measured via competitive radioimmunoassay. Cox regression models assessed associations between 25-OHD and cancer-specific death (case fatality) through 2012, given as hazard ratios (HRs) with 95% confidence intervals (CIs).Results: The median time between pre-diagnostic and diagnostic samples was 14.4 years. The median 25-OHD levels were 63.3 and 62.5 nmol/L, respectively. During follow-up, 313 cancer deaths occurred. Compared to low pre-diagnostic 25-OHD levels (

Bettina K Andreassen,1 Helga H Hektoen,1 Karol Axcrona,2 Hilde Langseth,1 Jo S Stenehjem,1 Trude E Robsahm1 1Department of Research, Cancer Registry of Norway, Oslo, Norway; 2Department of Urology, Akershus University Hospital, Lørenskog, NorwayCorrespondence: Helga H Hektoen Email Helga.Helseth.Hektoen@kreftregisteret.no View the original paper by Dr Hektoen and colleagues This is in response to the Letter to the Editor

Trude Eid Robsahm,1,* Per Helsing,2,* Yngvar Nilssen,1 Linda Vos,1 Syed Mohammad H Rizvi,2,3 Lars A Akslen,4,5 Marit B Veierød6 1Cancer Registry of Norway, Oslo, Norway; 2Department of Dermatology, Oslo University Hospital, Rikshospitalet, Oslo, Norway; 3Institute of Clinical Medicine, University of Oslo, Oslo, Norway; 4Centre for Cancer Biomarkers, Department of Clinical Medicine, Section for Pathology, University of Bergen, Bergen, Norway; 5Department of Pathology, Haukeland University Hospital, Bergen, Norway; 6Oslo Centre for Biostatistics and Epidemiology, Department of Biostatistics, Institute of Basic Medical Sciences, University of Oslo, Oslo, Norway*These authors contributed equally to this work Purpose: The purpose of this study was to examine why Norway has the highest rate of mortality due to cutaneous melanoma (CM) in Europe. The Norwegian Malignant Melanoma Registry (NMMR) enables the study of clinical and histopathological characteristics of patients who die due to CM. Patients and methods: The NMMR and the Norwegian Cause of Death Registry provided data on the clinical and histopathological factors as well as the date and cause of death, through June 2015 for all first invasive CMs diagnosed in 2008–2012 (n=8087). Cox regression was used to estimate associations between clinical and pathological factors and CM-specific death. Multiple imputation was used to handle missing data. Results: The CMs were equally distributed between men (49.9%) and women (50.1%), and the median follow-up was 4.0 years (range: 0.08–7.5 years). Trunk was the most common anatomic site (48%), superficial spreading melanoma was the dominant melanoma subtype (68.2%), median Breslow thickness was 1.0 mm, ulceration was present in 23% of CMs, and 91.8% of cases were in a local clinical stage at diagnosis. Compared to women, men were diagnosed at a higher age, with thicker and more-often-ulcerated tumor, and more often were in advanced clinical stages. During follow-up, 1015 patients died due to CM, representing 52.8% of all deaths. The nodular subtype made up the dominant proportion of fatal CM cases (55.3% in women, 64.6% in men). Sex, age, anatomic site (trunk), T-stage, ulceration, clinical stage, and having a second primary CM were associated with increased risk of CM-specific death. Conclusion: Our data suggest that the high rate of mortality due to CM observed in Norway is attributable to the more advanced stage of the disease at diagnosis. Most high-risk cases occurred in male patients ≥70 years of age. Efforts to improve awareness and secondary prevention of CM, including warning signs of all melanoma subtypes, are required urgently and should be targeted toward men in particular. Keywords: cutaneous melanoma, mortality, prognostic factors, diagnostic delay, epidemiology

Background: There is limited evidence of potential associations between body mass index (BMI) and risk of vulvar and vaginal cancer. We explored these associations in a large cohort of Norwegian women., Methods: The analytical dataset included 889,441 women aged 16-75 years at baseline in 1963-1975. Multivariable Cox regression analyses were used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) for the associations between BMI and vulvar and vaginal cancer incidence., Results: During 30.1 million person-years of follow-up, 1748 incident vulvar and 408 incident vaginal cancer cases occurred. The HRs (95% CIs) for vulvar cancer for a BMI of 15- < 18.5, 18.5- < 25, 25- < 30, 30- < 35, ≥ 35 were 0.62 (0.38-1.01), 1.00 (reference), 1.23 (1.10-1.40), 1.43 (1.23-1.66) and 1.72 (1.35-2.20, p trend  < 0.001), and per 5 kg/m 2 increment was 1.20 (1.13-1.26). The corresponding HRs (95% CIs) for vaginal cancer were 1.05 (0.52-2.15), 1.00, 0.89 (0.71-1.12), 0.95 (0.68-1.34), and 2.01 (1.29-3.13, p trend  < 0.001), respectively, and per 5 kg/m 2 was 1.11 (0.99-1.25). The HR (95% CI) per 5 kg/m 2 increase in BMI at ages 16-29 was 1.28 (1.07-1.54, n = 250 cases) for vulvar and 1.53 (1.11-2.11, n = 66 cases) for vaginal cancers. The HR (95% CI) per 5 kg/m 2 for early-onset (< 50 years age at diagnosis) vulvar cancer was 0.92 (0.66-1.28, n = 87 cases) and 1.70 (1.05-2.76, n = 21 cases) for vaginal cancer., Conclusion: These results further support the associations between higher BMI and increased risk of vulvar and vaginal cancers, with suggestive stronger associations between BMI in early adulthood for both cancers and for early-onset vaginal cancer. Further studies are needed to elucidate these findings and investigate the underlying mechanisms., (© 2024. The Author(s).)

Monitoring melanoma incidence time trends by tumour thickness is essential to understanding the evolution of melanoma occurrence and guiding prevention strategies. To assess long-term incidence trends, tumour thickness was extracted from pathology reports in the Cancer Registry of Norway (1983-2007) and the Norwegian Melanoma Registry (2008-2019), n = 45,635 patients. Across all anatomic sites, T1 (≤ 1 mm) incidence increased most (men annual percentage change [AAPC] = 4.6, 95% confidence interval [95% CI] 4.2-5.0; women AAPC = 3.2, 95% CI 2.8-3.6); the increase was steep until 1989/90, followed by a plateau, and a further steep increase from 2004/05. Increased incidence was also observed for T2 (>1.0-2.0) melanoma (men AAPC = 2.8, 95% CI 2.4-3.2; women AAPC = 1.5, 95% CI 1.1-1.9), and T3 (>2.0-4.0) in men (AAPC = 1.4, 95% CI 0.9-1.9). T4 (>4.0) melanoma followed a similar overall pattern (men AAPC = 1.3, 95% CI 0.9-1.7, head/neck, upper limbs, and trunk; women AAPC = 0.9, 95% CI 0.4-1.4, upper limbs and trunk). Men had the highest T3 and T4 incidence and the sex difference increased with age. Regarding birth cohorts, age-specific incidence increased in all T categories in the oldest age groups, while stabilizing in younger patients born after 1950. Overall, the steep increase in T1 melanoma was not accompanied by a decrease in thick melanoma.

Purpose: In a population-based cohort of 960 uveal melanoma (UM) patients, we describe patients with three additional malignancies, including one unique patient with four synchronous primary malignancies., Method: A descriptive presentation of the clinical course and outcome for UM patients with three additional primary malignancies., Results: After more than 20 years of follow-up of the UM cohort, 11 patients (1.1%) were diagnosed with three additional primary malignancies before, simultaneously or after UM. Among these, one patient had four synchronous primary malignancies, detected during workup for a symptomatic UM. All diagnoses were treated during the following 4 months, firstly the breast cancer, thereafter, the lung and pancreatic cancers and finally the UM. The patient died 3 years later of abdominal carcinomatosis due to the pancreatic cancer. The family history and gene testing did not disclose any genetic predisposition for cancer. A comparison of the four synchronous tumours, morphologically and immunohistochemically, showed no similarities and the expression of antibodies was different., Conclusion: Patients with UM may be diagnosed with non-ocular additional primary cancers. Thus, a comprehensive workup is obligatory and a further follow-up of the UM patients seems necessary. The UM is not always the main problem., (© 2024 The Authors. Acta Ophthalmologica published by John Wiley & Sons Ltd on behalf of Acta Ophthalmologica Scandinavica Foundation.)

Importance: Patients diagnosed with a primary melanoma are at high risk of subsequent melanomas. Understanding the risk of second primary invasive melanoma and associated factors is crucial to optimize patient follow-up., Objective: To assess the incidence rate of second primary invasive melanoma and time between the first and second primary invasive melanoma in the Norwegian population., Design, Setting, and Participants: This population-based cohort study included data from deidentified records of all invasive melanomas diagnosed in Norway in 2008 to 2020, obtained from the Cancer Registry of Norway. Data were from adults aged 18 years or older diagnosed with a first primary melanoma. Data analysis was performed from March to August 2023., Main Outcomes and Measures: The main outcome was the incidence rate of second primary invasive melanoma at least 30 days after the first. Accelerated failure time models were fitted to examine potential associations with patient and tumor characteristics. Median time between first and second primary melanomas and 95% CIs were calculated. The likelihood of, and median interval for, second primary melanomas on the same or different site as the first primary were calculated., Results: A total of 19 196 individuals aged 18 years or older were diagnosed with a first primary melanoma. The mean (SD) age at diagnosis of the first primary melanoma was 62 (16) years (range, 18-104 years), and 9763 (51%) were female. The incidence rate in the year following diagnosis was 16.8 (95% CI, 14.9-18.7) per 1000 person-years, which decreased to 7.3 (95% CI, 6.0-8.6) during the second year and stabilized thereafter. Median time between first and second primaries decreased with advancing age and was 37 months (95% CI, 8-49) in patients younger than 40 years, 18 (95% CI, 13-24) in patients aged 50 to 59 years, and 11 (95% CI, 7-18) in patients aged 80 years or older. The second primary was on the same site as their first primary for 47% (359 patients), and on a different site for 53% (407 patients). The median interval until second melanoma on the same site as the initial melanoma was 12 (95% CI, 7-19) months in men and 22 (95% CI, 11-35) months in women., Conclusions and Relevance: Older age and male sex were associated with an increased risk, suggesting that increased surveillance intensity may be considered for men, especially those older than 50 years, for at least 3 years after their initial diagnosis, regardless of the characteristics of their first invasive melanoma.

To estimate occurrence of non-communicable diseases (NCDs) over the life-course in the Norwegian population, national health registries are a vital source of information since they fully represent the entire non-institutionalised population. However, as they are mainly established for administrative purposes, more knowledge about how NCDs are recorded in the registries is needed. To establish this, we begin by counting the number of individuals registered annually with one or more NCDs in any of the registries. The study population includes all inhabitants who lived in Norway from 2004 to 2020 ( N ~6.4m). The NCD outcomes are diabetes, cardiovascular diseases, chronic obstructive lung diseases, cancer and mental disorders/substance use disorders. Further, we included hip fractures in our NCD concept. The data sources used to identify individuals with NCDs, including detailed information on diagnoses in primary and secondary health care and dispensings of prescription drugs, are the Cancer Registry of Norway, The Norwegian Patient Registry, The Norwegian Control and Payment of Health Reimbursement database, and The Norwegian Prescription Database. The number of individuals registered annually with an NCD diagnosis and/or a dispensed NCD drug increased over the study period. Changes over time may reflect changes in disease incidence and prevalence, but also changes in disease-specific guidelines, reimbursement schemes and access to and use of health services. Data from more than one health registry to identify individuals with NCDs are needed since the registries reflect different levels of health care services and therefore may reflect disease severity., Competing Interests: Data sharing statementThe authors are not permitted to share data within this research project with others. However, interested readers can apply to the Norwegian Health Data Authority and Statistics Norway to obtain access to registry data. At the end of the project period, we will publish our Data Management Plan, describing how we handled our research data throughout the project. Declaration of conflicting interestsThe authors have no conflicts of interest to declare.

Background: The European-funded Health Effects of Cardiac Fluoroscopy and Modern Radiotherapy in Pediatrics (HARMONIC) project is a multicenter cohort study assessing the long-term effects of ionizing radiation in patients with congenital heart disease. Knowledge is lacking regarding the use of ionizing radiation from sources other than cardiac catheterization in this cohort., Objective: This study aims to assess imaging frequency and radiation dose (excluding cardiac catheterization) to patients from a single center participating in the Norwegian HARMONIC project., Materials and Methods: Between 2000 and 2020, we recruited 3,609 patients treated for congenital heart disease (age < 18 years), with 33,768 examinations categorized by modality and body region. Data were retrieved from the radiology information system. Effective doses were estimated using International Commission on Radiological Protection Publication 60 conversion factors, and the analysis was stratified into six age categories: newborn; 1 year, 5 years, 10 years, 15 years, and late adolescence., Results: The examination distribution was as follows: 91.0% conventional radiography, 4.0% computed tomography (CT), 3.6% diagnostic fluoroscopy, 1.2% nuclear medicine, and 0.3% noncardiac intervention. In the newborn to 15 years age categories, 4-12% had ≥ ten conventional radiography studies, 1-8% underwent CT, and 0.3-2.5% received nuclear medicine examinations. The median effective dose ranged from 0.008-0.02 mSv and from 0.76-3.47 mSv for thoracic conventional radiography and thoracic CT, respectively. The total effective dose burden from thoracic conventional radiography ranged between 28-65% of the dose burden from thoracic CT in various age categories (40% for all ages combined). The median effective dose for nuclear medicine lung perfusion was 0.6-0.86 mSv and for gastrointestinal fluoroscopy 0.17-0.27 mSv. Because of their low frequency, these procedures contributed less to the total effective dose than thoracic radiography., Conclusion: This study shows that CT made the largest contribution to the radiation dose from imaging (excluding cardiac intervention). However, although the dose per conventional radiograph was low, the large number of examinations resulted in a substantial total effective dose. Therefore, it is important to consider the frequency of conventional radiography while calculating cumulative dose for individuals. The findings of this study will help the HARMONIC project to improve risk assessment by minimizing the uncertainty associated with cumulative dose calculations., (© 2023. The Author(s).)

Background: The aim of this study was to explore the associations between BMI and cancer of the liver, bile ducts, and gallbladder., Methods: A registry-based cohort study was performed by linking data from several national registries in Norway., Results: The cohort comprised 1 723 692 individuals including 4768 hepatobiliary cancer cases during 55 743 509 person-years of follow-up. In men, we found increased risk of cancer per 5 kg/m 2 BMI increase for hepatocellular carcinoma and extrahepatic cholangiocarcinoma. In women there was increased risk of extrahepatic cholangiocarcinoma and gallbladder cancer. Women with high BMI in early adulthood had increased risk of intrahepatic cholangiocarcinoma. Reduced cancer-specific survival was found for all hepatobiliary malignancies in women with overweight and obesity. In men, reduced survival was observed in individuals with obesity for all hepatobiliary cancers, except gallbladder cancer. Increased risk of cancer-death per 5 kg/m 2 BMI increase was found for hepatocellular carcinoma, intra-, and extrahepatic cholangiocarcinoma in women. For men, 5 kg/m 2 BMI increase was positively associated with cancer-death from intrahepatic cholangiocarcinoma., Discussion: This study supports the notion of an increased risk of hepatobiliary cancers with increasing BMI, with sex and age variations. The findings also suggest a higher risk of cancer-death with increasing BMI., Competing Interests: Declarations of competing interest None to declare., (Copyright © 2023 The Author(s). Published by Elsevier Ltd.. All rights reserved.)

Noncommunicable diseases (NCDs) are a leading cause of premature death globally and have common preventable risk factors. In Norway, the NCDNOR-project aims at establishing new knowledge in the prevention of NCDs by combining information from national registries with data from population-based health studies. In the present study, we aimed to harmonize data on key NCD risk factors from the health studies, describe clustering of risk factors using intersection diagrams and latent class analysis, and identify long-term risk factor trajectories using latent class mixed models. The harmonized study sample consisted of 808,732 individuals (1,197,158 participations). Two-thirds were exposed to ≥ 1 NCD risk factor (daily smoking, physical inactivity, obesity, hypertension, hypercholesterolaemia or hypertriglyceridaemia). In individuals exposed to ≥ 2 risk factors (24%), we identified five distinct clusters, all characterized by fewer years of education and lower income compared to individuals exposed to < 2 risk factors. We identified distinct long-term trajectories of smoking intensity, leisure-time physical activity, body mass index, blood pressure, and blood lipids. Individuals in the trajectories tended to differ across sex, education, and body mass index. This provides important insights into the mechanisms by which NCD risk factors can occur and may help the development of interventions aimed at preventing NCDs., (© 2023. Springer Nature Limited.)

Importance: Cutaneous squamous cell carcinoma (cSCC) may occur with multiple primary tumors, metastasize, and cause death both in immunocompetent and immunosuppressed patients., Objective: To study the rates of second cSCC, metastasis, and death from cSCC in patients with and without organ transplant-associated immunosuppressive treatment., Design, Setting, and Participants: This population-based, nationwide cohort study used Cancer Registry of Norway data from 47 992 individuals diagnosed with cSCC at 18 years or older between January 1, 1968, and December 31, 2020. Data were analyzed between November 24, 2021, and November 15, 2022., Exposures: Receipt of a solid organ transplant at Oslo University Hospital between 1968 and 2012 followed by long-term immunosuppressive treatment., Main Outcomes and Measures: Absolute rates of second cSCC, metastasis, and death from cSCC were calculated per 1000 person-years with 95% CIs. Hazard ratios (HRs) estimated using Cox proportional hazard regression were adjusted for age, sex, and year of first cSCC diagnosis., Results: The study cohort comprised 1208 organ transplant recipients (OTRs) (median age, 66 years [range, 27-89 years]; 882 men [73.0%] and 326 women [27.0%]) and 46 784 non-OTRs (median age, 79 years [range, 18-106 years]; 25 406 men [54.3%] and 21 378 women [45.7%]). The rate of a second cSCC per 1000 person-years was 30.9 (95% CI, 30.2-31.6) in non-OTRs and 250.6 (95% CI, 232.2-270.1) in OTRs, with OTRs having a 4.3-fold increased rate in the adjusted analysis. The metastasis rate per 1000 person-years was 2.8 (95% CI, 2.6-3.0) in non-OTRs and 4.8 (95% CI, 3.4-6.7) in OTRs, with OTRs having a 1.5-fold increased rate in the adjusted analysis. A total of 30 451 deaths were observed, of which 29 895 (98.2%) were from causes other than cSCC. Death from cSCC was observed in 516 non-OTRs (1.1%) and 40 OTRs (3.3%). The rate of death from cSCC per 1000 person-years was 1.7 (95% CI, 1.5-1.8) in non-OTRs and 5.4 (95% CI, 3.9-7.4) in OTRs, with OTRs having a 5.5-fold increased rate in the adjusted analysis., Conclusions and Relevance: In this cohort study, OTRs with cSCC had significantly higher rates of second cSCC, metastasis, and death from cSCC than non-OTRs with cSCC, although most patients with cSCC in both groups died from causes other than cSCC. These findings are relevant for the planning of follow-up of patients with cSCC and for skin cancer services.

Purpose: The purpose of this study is to explore the frequency of additional primary malignancies in uveal melanoma (UM) patients and cause-specific mortality, to help guide surveillance strategies after UM., Methods: All patients diagnosed with UM at Oslo University Hospital during 1990-2017 were eligible for inclusion. Linkage to the Cancer Registry of Norway obtained information on additional malignancies and cause of death throughout 2019. UM patients were categorized according to timing of additional malignancy (prior/simultaneously or after UM) or no additional cancer, and by UM stage at diagnosis. Age-adjusted mortality rates were presented per 1000 person-years with 95% confidence intervals (CI)., Results: The study population included 960 UM patients: 77% were diagnosed in stage and I/II and 56% were men. Mean age at diagnosis was 63 years. Additional malignancies were observed in 152 patients prior/simultaneous to UM, and in 120 patients >1 year after UM. Overall, mortality per 1000 person-years was 3.5 (95% CI 3.1-3.9) for UM and 3.0 (2.6-3.4) for other causes. Lowest UM mortality [1.3 (0.60-2.1)] was seen in patients with a second malignancy after UM, regardless of stage. Highest UM mortality was seen for UM patients in stage III/IV, both without [16.1 (13.2-19.1)] and with any additional malignancy [16.9 (6.6-27.3)]., Conclusion: Our results support that UM patients frequently have additional malignancies, both before and after UM. Low-UM mortality in patients with a primary malignancy after UM, might indicate less aggressive UM. The cumulative UM mortality flattens about 10 years after diagnosis and annual follow-up of patients for 10 years seems adequate., (© 2023 Acta Ophthalmologica Scandinavica Foundation. Published by John Wiley & Sons Ltd.)

Background: Night shift work may acutely disrupt the circadian rhythm, with possible carcinogenic effects. Prostate cancer has few established risk factors though night shift work, a probable human carcinogen, may increase the risk. We aimed to study the association between night shift work and chlorinated degreasing agents (CDAs) as possible endocrine disrupters in relation to aggressive prostate cancer as verified malignancies., Methods: We conducted a case-cohort study on 299 aggressive prostate cancer cases and 2056 randomly drawn non-cases in the Norwegian Offshore Petroleum Workers cohort (1965-98) with linkage to the Cancer Registry of Norway (1953-2019). Work history was recorded as years with day, night, and rollover (rotating) shift work, and CDA exposure was assessed with expert-made job-exposure matrices. Weighted Cox regression was used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) for aggressive prostate cancer, adjusted for education and year of first employment, stratified by 10-year birth cohorts, and with 10, 15, and 20 years of exposure lag periods., Results: Compared with day work only, an increased hazard of aggressive prostate cancer (HR = 1.86, 95% CI 1.18-2.91; P-trend = 0.046) was found in workers exposed to ≥19.5 years of rollover shift work. This persisted with longer lag periods (HR = 1.90, 95% CI 0.92-3.95; P-trend = 0.007). The exposure-hazard curve for a non-linear model increased linearly (HRs ≥1.00) for 18-26 years of rollover shift work. No association was found with CDA exposure., Conclusions: Long-term exposure to rollover shift work may increase the hazard of aggressive prostate cancer in offshore petroleum workers., (© The Author(s) 2022. Published by Oxford University Press on behalf of the International Epidemiological Association.)

Background: Most antihypertensives can induce dermal photosensitivity, which may increase melanoma risk. However, corroborating evidence is limited. We examined the associations between use of antihypertensives and melanoma risk., Methods: A nationwide nested case-control study was conducted using data from the Cancer Registry of Norway, the National Registry and the Norwegian Prescription Database in 2004-15. Ten controls were randomly selected for each melanoma case, matched on sex and birth year. The study included 12 048 cases and 117 895 controls. We estimated rate ratios (RRs) with 95% confidence intervals (CIs). All analyses were adjusted for ambient ultraviolet radiation (UVR). We additionally performed active comparator analyses, and sensitivity analyses by only including new users, distinguishing between exclusive and mixed users, allowing for different latency periods, and subgroup analyses by melanoma subtype and clinical stage., Results: Compared with non-use, we observed a slightly increased melanoma risk in users of diuretics (RR 1.08, CI 1.01-1.15), calcium-channel blockers (RR 1.10, CI 1.04-1.18) and drugs affecting the renin-angiotensin system (RR 1.10, CI 1.04-1.16), but not for beta blockers (RR 0.97, CI 0.92-1.03). We found no heterogeneity of associations by melanoma subtype or clinical stage and no dose-response relationship between the cumulative defined daily doses (DDDs) and melanoma. No interaction was found between cumulative DDDs and ambient UVR., Conclusions: Weak associations, with lack of a dose-response relationship and lack of interactions with ambient UVR, in the DDD analysis in this nationwide study do not support a causal relationship between antihypertensives and melanoma risk., (© The Author(s) 2022. Published by Oxford University Press on behalf of the International Epidemiological Association.)

Competing Interests: Conflicts of interest The authors declare they have no conflicts of interest.

Competing Interests: Conflicts of interest the authors declare they have no conflicts of interest.

Little is known about if and how nevi and pigmentation are associated with melanoma-specific mortality. However, increased melanoma awareness in people with lighter pigmentation and many nevi may result in earlier diagnosis of thinner less-lethal tumors. The aim of this study was to investigate associations between nevus count (asymmetrical > 5 mm and small symmetrical), pigmentary characteristics (hair colour, eye colour, skin colour, freckling, pigmentary score), and melanoma-specific mortality in subjects with melanomas > 1 mm. Data from the Norwegian Women and Cancer cohort, established in 1991, with complete follow-up of melanoma patients until 2018 through the Cancer Registry of Norway, were used to estimate hazard ratios with 95% confidence intervals for the associations between nevus count, pigmentary characteristics, and melanoma-specific mortality, stratified by tumor thickness using Cox regression. Estimated hazard ratios consistently indicated a higher risk of melanoma death for those with darker vs lighter pigmentary characteristics in patients with tumors > 1.0-2.0 mm and > 2.0 mm thick (e.g. pigmentary score hazard ratio 1.25, 95% confidence interval (0.74-2.13)). Among women with melanomas > 1.0 mm thick, lighter pigmentation and asymmetrical nevi may be associated with lower melanoma-specific mortality, suggesting that factors that increase the risk of melanoma may also be associated with decreased risk of death from melanoma.

Aim: The aim was to explore potential associations between the body mass index (BMI) and the risk of colorectal cancer (CRC), including subsites of the colon, and cancer-specific death., Methods: A registry-based cohort study was conducted with baseline data gathered from the Norwegian Tuberculosis Screening Programme, collected between 1963 and 1975, and linked to follow-up data from the Cancer Registry of Norway and the Norwegian Cause of Death Registry. Cox regression models were used to explore associations between BMI and CRC risk and cancer-specific death., Results: Of 1 723 692 included individuals, 76 616 developed CRC during 55 370 707 person-years of follow-up. In men, a 5 kg/m 2 increase in BMI was associated with an increased risk of colon cancer, including both right and left subsites, and rectal cancer. Allowing for nonlinearities, we found a U-shaped association for the right colon and an inverse U-shape for the left colon and rectum cancer. In women, a 5 kg/m 2 increase in BMI in early adulthood was associated with increased risk of colon cancer, including both subsites. In women, an increased risk of CRC death with increasing BMI was found for colon cancer., Conclusions: Men of all ages have an increased risk of CRC with increasing BMI, with the highest risk for right-sided colon cancer. An increased risk for colon cancer was also found in women with high BMI in early adulthood. Furthermore, women of all age groups appeared to have an increased risk of CRC death with higher BMI., (© 2022 The Authors. Colorectal Disease published by John Wiley & Sons Ltd on behalf of Association of Coloproctology of Great Britain and Ireland.)

Background and Objective: An association between body mass index (BMI) and pancreatic cancer is suggested in observational studies. However, further studies are required to substantiate available evidence. The aim of this study was to explore the association between BMI and pancreatic ductal adenocarcinoma (PDAC) risk, treatment, and mortality., Methods: A registry-based cohort study was performed by combining data from four registries in Norway. Baseline data were collected between 1963 and 1975 with follow-up data collected until 2018. Kaplan-Meier curves and multivariable Cox regressions were estimated. Chi-square tests were used to analyze differences between groups., Results: The study cohort consisted of 1,723,692 individuals. A total of 8973 PDAC cases were identified during 55,744,749 person-years of follow-up. A 5 kg/m 2 increase in BMI was associated with an increased risk of PDAC if high BMI at young age (16-29 years) (hazard ratio (HR): 1.21, 95% confidence interval (CI): 1.13-1.31), both for men (HR: 1.30, 95% CI: 1.15-1.46) and women (HR: 1.16, 95% CI: 1.05-1.28). In men, there was a 52% increase in risk of early-onset PDAC (2 increase in BMI. A total of 2645 individuals were diagnosed with stage 1-3 disease, of whom 1131 underwent curative surgery. In all, 49% of normal weight, 38% overweight, and 30% obese individuals with stage 1-3 PDAC underwent surgery with curative intent (p < 0.001). Cancer survival was lower in overweight and obese individuals for both sexes. Analysis adjusted for sex, age, and period of diagnosis confirmed increased risk of cancer death in obese individuals., Conclusion: This study suggests that increased BMI in young adults may increase the risk of PDAC, and higher BMI in men is associated with an increased risk of early onset PDAC (

Background: The Prostate Cancer Cohort Consortium (PC3) Working Group proposed a definition for aggressive prostate cancer (PC) for aetiologic epidemiologic research. We aimed to validate this definition as well as a second approach utilising only information on stage at diagnosis., Methods: First primary PCs diagnosed 2004 - 2009 in the population-based Janus Serum Bank (JSB) cohort were identified by linkage to the population-based Cancer Registry of Norway (CRN) ( n  = 3568). The CRN and Norwegian Prostate Cancer Registry provided clinicopathological data for these cases. Approach 1 classified PC as aggressive if it was clinically T4, or N1, or M1, or had a Gleason score ≥8 at diagnosis (as proposed). Approach 2 classified PC as aggressive if CRN stage at diagnosis was 'regional spread' or 'distant metastases'. Both approaches were validated by calculating the sensitivity and positive predictive value (PPV) against PC-death within 10 years of diagnosis., Results: Overall, 555 died from PC within 10 years. Approach 1 classified 24.7% of cases as aggressive and 13.6% were unclassified due to missing information. Approach 2 classified 19.6% as aggressive and 29% were unclassified. Sensitivity was highest for Approach 1 (0.76, 95% CI: 0.72 - 0.80 vs 0.69, 95% CI: 0.64 - 0.73), while PPVs were similar for both approaches (0.43, 95% CI: 0.40 - 0.46 and 0.40, 95% CI: 0.36 - 0.44). We observed similarly high sensitivity and higher PPVs than those reported by the PC3 Working Group., Conclusions: The proposed definition of aggressive PC was applicable and valid in the JSB cohort. Stage at diagnosis can be useful if data on cTNM or Gleason score is unavailable.

Laboratory and animal research support a protective role for vitamin D in breast carcinogenesis, but epidemiologic studies have been inconclusive. To examine comprehensively the relationship of circulating 25-hydroxyvitamin D [25(OH)D] to subsequent breast cancer incidence, we harmonized and pooled participant-level data from 10 U.S. and 7 European prospective cohorts. Included were 10,484 invasive breast cancer cases and 12,953 matched controls. Median age (interdecile range) was 57 (42-68) years at blood collection and 63 (49-75) years at breast cancer diagnosis. Prediagnostic circulating 25(OH)D was either newly measured using a widely accepted immunoassay and laboratory or, if previously measured by the cohort, calibrated to this assay to permit using a common metric. Study-specific relative risks (RRs) for season-standardized 25(OH)D concentrations were estimated by conditional logistic regression and combined by random-effects models. Circulating 25(OH)D increased from a median of 22.6 nmol/L in consortium-wide decile 1 to 93.2 nmol/L in decile 10. Breast cancer risk in each decile was not statistically significantly different from risk in decile 5 in models adjusted for breast cancer risk factors, and no trend was apparent (P-trend = 0.64). Compared to women with sufficient 25(OH)D based on Institute of Medicine guidelines (50- < 62.5 nmol/L), RRs were not statistically significantly different at either low concentrations (< 20 nmol/L, 3% of controls) or high concentrations (100- < 125 nmol/L, 3% of controls; ≥ 125 nmol/L, 0.7% of controls). RR per 25 nmol/L increase in 25(OH)D was 0.99 [95% confidence intervaI (CI) 0.95-1.03]. Associations remained null across subgroups, including those defined by body mass index, physical activity, latitude, and season of blood collection. Although none of the associations by tumor characteristics reached statistical significance, suggestive inverse associations were seen for distant and triple negative tumors. Circulating 25(OH)D, comparably measured in 17 international cohorts and season-standardized, was not related to subsequent incidence of invasive breast cancer over a broad range in vitamin D status., (© 2023. This is a U.S. Government work and not under copyright protection in the US; foreign copyright protection may apply.)

Aim: This study was performed to investigate the characteristics and overall survival (OS) of patients with completely resected stage IIB-IV cutaneous melanoma identified in the Cancer Registry of Norway. Methods: A retrospective cohort study of all adult patients with stage ≥IIB cutaneous melanoma was performed in Norway (January 2008 to December 2018), excluding patients with stage IV melanoma without evidence of surgery. Results: 5-year OS varied by stage (IIB 65%, IIC 38%, IIIA 79%, IIIB 66%, IIIC 52%, IIID 37% and IV 39%). Adjusted Cox models showed that stage IIIA and IIIB patients showed similar survival to stage IIB patients (hazard ratio [95% CI]: IIIA 0.67 [0.44-1.04]; IIIB 1.18 [0.96-1.45]), while all other stages had lower survival than IIB. Conclusion: Survival for stage II patients, particularly IIC, can be poor and in some cases worse than patients with more advanced stage melanoma. Our data highlight an unmet need for effective adjuvant treatment options among stage IIB/C patients.

Objectives: At present, there is no cure for osteoarthritis (OA), but severe hip joint degeneration can require total hip arthroplasty (THA). The literature on OA after elite sport is limited. We hypothesise that elite athletic activity increases the risk of receiving a THA later in life., Methods: We linked a cohort of former Norwegian world-class athletes (1402 females and 1902 males, active 1936-2006) to the Norwegian Arthroplasty Register (THA performed 1987-2020). We used standardised incidence ratio (SIR), one-minus Kaplan-Meier and relative Cox regression (relative HR, RHR), with 95% CIs, and funnel plots at age 75, to assess THA risk for different sport disciplines, joint impact categories of sport disciplines and sex. The risk of THA for the corresponding general Norwegian population was used as reference., Results: We found an overall increased risk for THA for the former elite athletes (SIR 2.11, 95% CI 1.82 to 2.40) at age 75 years, compared with the general population. THA risk at age 75 years was 11.6% for female athletes and 8.3% for male athletes. SIR was 1.90 (95% CI 1.49 to 2.31) for female and 2.28 (95% CI 1.87 to 2.70) for male athletes. Among males, high joint impact sport disciplines were associated with increased risk compared with low-impact sport disciplines (RHR 1.81, 95% CI 1.06 to 3.08, p=0.029)., Conclusion: Having been an elite athlete was associated with a doubling of THA risk compared with the general population for both sexes. High joint impact sport disciplines were associated with subsequent THA for male athletes., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2022. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

Importance: To our knowledge, no study has prospectively investigated sunburn patterns over age periods from childhood to adulthood and their associations with skin cancer risk., Objective: To identify lifetime trajectories of sunburns and compare the association between these trajectories and subsequent risk of cutaneous melanoma and squamous cell carcinoma (cSCC)., Design, Setting, and Participants: This population-based cohort study included participants from the Norwegian Women and Cancer Study, established in 1991, with follow-up through 2018. Baseline questionnaires were issued from 1991 to 2007, with follow-up questionnaires every 5 to 7 years. Data analysis was performed from March 16, 2021, to December 4, 2021., Exposures: Participants reported pigmentation factors, sunbathing vacations, and indoor tanning. Annual frequencies of sunburns were reported for childhood, adolescence, and adulthood., Main Outcomes and Measures: Information on cancer diagnoses, emigration, and death were obtained through linkage to the Cancer Registry of Norway using the unique personal identification number of Norwegian citizens., Results: Of the 172 472 women (age range, 31-70 years) who returned questionnaires, 169 768 received questions about sunburns at study inclusion. Five classes (stable low, low-moderate-low, low to high, high to low, and stable high) of individual lifetime sunburn trajectories with similar shapes were estimated in 3 samples up to 39 years (n = 159 773), up to 49 years (n = 153 297), and up to 59 years (n = 119 170). Mean follow-up ranged from 14.3 to 19.5 years in the 3 samples, during which 1252 to 1774 women were diagnosed with incident primary melanoma and 739 to 871 women with incident primary cSCC. With hazard ratios (HRs) and 95% CIs estimated using a Cox proportional hazards model, the stable high and high to low trajectories showed statistically significant increased melanoma and cSCC risks compared with the stable low trajectory across all samples (≤39 years for stable high and high to low trajectories: melanoma: HR, 1.50 [95% CI, 1.28-1.75] and HR, 1.44 [95% CI, 1.20-1.73]; cSCC: HR, 1.51 [95% CI, 1.22-1.87] and HR, 1.47 [95% CI, 1.14-1.91]). Other trajectories showed increased risk, though generally weaker and mainly estimates that were not statistically significant. There was no statistically significant heterogeneity between melanoma and cSCC estimates., Conclusion and Relevance: This cohort study showed that high sunburn frequency throughout life was associated with increased melanoma and cSCC risk. Furthermore, sunburns in childhood are especially important for subsequent risk of these skin cancers. Avoiding sunburns throughout life, in particular in childhood, is therefore crucial.

Epidemiological studies on statin use in relation to skin cancer risk are scarce and yielded conflicting results. We explored this association in Etude Epidémiologique auprès de femmes de l'Education Nationale, a prospective cohort of French women born in 1925-1950. Health and lifestyle data were self-reported biennially and matched with drug reimbursement data, allowing the identification of participants' statin use since 2004. Multivariable cause-specific hazards regression models adjusted for skin cancer risk factors estimated hazard ratios with 95% confidence intervals. Over 2004-2014, 455 cutaneous melanoma, 1,741 basal cell carcinoma, and 268 squamous cell carcinoma cases were ascertained among 62,473 women. Compared with never use, there were no associations between ever use of statins and melanoma (hazard ratio = 1.16, 95% confidence interval = 0.94-1.44) or squamous cell carcinoma (hazard ratio = 0.89, 95% confidence interval = 0.66-1.19) risks and a decrease in basal cell carcinoma risk with ever use of statins (hazard ratio = 0.89, 95% confidence interval = 0.79-0.996). We found no trend of increasing or decreasing risks with dose, duration of use, time since first use, or age at first use and no statistically significant effect modification by pigmentary traits or residential UVR exposure. Because of the limited number of studies evaluating the associations between the use of statins and the risks of melanoma, basal cell carcinoma, and squamous cell carcinoma, these findings would deserve further investigation in other settings., (Copyright © 2021 The Authors. Published by Elsevier Inc. All rights reserved.)

Objectives: This study examined the association between night shift work and risk of breast cancer, overall and by hormone receptor subtype, among females in the Norwegian Offshore Petroleum Workers (NOPW) cohort. We also examined the association of coexposure (chlorinated degreasers and benzene) and breast cancer risk, and possible interaction with work schedule., Design: Prospectively recruited case-cohort study within the NOPW cohort., Setting: Female offshore petroleum workers active on the Norwegian continental shelf., Participants: 600 female workers (86 cases and 514 non-cases) were included in the study. We excluded workers that died or emigrated before start of follow-up, had missing work history, were diagnosed with breast cancer or other prior malignancy (except non-melanoma skin cancer) before start of follow-up., Results: No overall association was found between breast cancer risk and work schedule (HR 0.87, 95% CI 0.52 to 1.46 for work schedule involving night shift vs day shift only). There was no significant association between work schedule and risk of any breast cancer subtype. No significant interactions were found between work schedule and chemical coexposures (breast cancer overall P interaction chlorinated degreasers =0.725 and P interaction benzene =0.175)., Conclusions: Our results did not provide supporting evidence that work schedule involving night shift affects breast cancer risk in female offshore petroleum workers, but should be considered cautiously due to few cases. Further studies with larger sample sizes are warranted., Competing Interests: Competing interests: JSS and TKG have received a grant from the Research Council of Norway (governmental agency) that awarded an industry-collaborative grant to the Cancer Registry of Norway (governmental agency) in 2019 to establish a cohort of offshore petroleum workers. A condition pertaining to industry-collaborative grants is that 20% (US$175 000) of the grant was provided by the petroleum industry and 80% (US$700 000) by the Research Council itself with the intention of joining forces for the common interest of occupational health among petroleum workers. The application process was governed by the Research Council without any involvement from the industry. The grant does not cover the PIs or any of the collaborators salary., (© Author(s) (or their employer(s)) 2022. Re-use permitted under CC BY. Published by BMJ.)

Evidence on sunscreen use and cutaneous squamous cell carcinoma (cSCC) risk is limited. Most studies have not taken sun protection factor (SPF) into consideration and used nonusers of sunscreen as the reference group. Nonusers are likely a priori at lower cSCC risk than users. No study has investigated the effect of high- versus low-SPF sunscreens on cSCC, appropriately adjusting for time-varying confounding. Using data from the Norwegian Women and Cancer Study (1991-2016), we investigated whether use of SPF ≥15 versus SPF <15 sunscreens reduces cSCC risk. We used a marginal structural Cox proportional hazards model with inverse probability of treatment and censoring weights to estimate hazard ratios (HRs) and 95% confidence intervals (CIs). During follow-up of 148,781 women (mean follow-up, 14.3 years), 653 women were diagnosed with cSCC. The effect on cSCC risk of sunscreens with SPF ≥15 versus SPF <15 was close to the null when used at any latitudes (HR = 1.02, 95% CI: 0.82, 1.27) and when used in lower-latitude settings (HR = 1.05, 95% CI: 0.84, 1.32). In conclusion, we found no indication that sunscreens with SPF ≥15 reduced Norwegian women's cSCC risk more than sunscreens with SPF <15, suggesting that either there is no difference in their effects long-term or the difference is diluted by incorrect application., (© The Author(s) 2021. Published by Oxford University Press on behalf of the Johns Hopkins Bloomberg School of Public Health.)

Physical activity (PA) is an important factor in cancer prevention, but positive association between PA and risk of cutaneous melanoma found in recent studies may complicate this strategy. Ultraviolet radiation (UVR) exposure during outdoor PA is a plausible explanation for a positive association. We investigated the associations between PA, UVR and melanoma risk in the Norwegian Women and Cancer cohort. Overall PA was reported by 151,710 women, aged 30-75 at inclusion, using a validated 10-point-scale at enrolment and during follow-up, together with recent numbers of sunburns, indoor tanning sessions and weeks on sunbathing vacations. Seasonal outdoor walking and seasonal PAs were recorded in subsamples (n = 102,671 and n = 29,077, respectively). Logistic and Cox regression were used. Mean follow-up was 18.5 years, and 1565 invasive incident melanoma cases were diagnosed. Overall PA was inversely associated with sunburns, while positively associated with sunbathing vacations and indoor tanning. Overall PA was not associated with melanoma risk in all body sites combined (p trend  = 0.61), but reduced risk was found in upper limb melanomas (hazard ratio (HR) = 0.70, 95% confidence interval (CI) 0.51-0.96; high versus low PA). Non-significant reduced risks were found for seasonal outdoor walking >2 h/day versus 30-60 min/day (summer HR = 0.81, 95% CI 0.66-1.00; autumn HR = 0.74, 95%CI 0.55-1.01). Seasonal PAs were not associated with melanoma risk. In conclusion, we found positive associations between overall PA and sunbathing vacations and indoor tanning, and, unlike literature, inverse association between overall PA and sunburns. Our results do not support a positive association between PA and melanoma risk in Norwegian women., (Copyright © 2021 The Author(s). Published by Elsevier Inc. All rights reserved.)

Purpose: The Oslo Ischaemia Study was designed to investigate the prevalence and predictors of silent coronary disease in Norwegian middle-aged men, specifically validating exercise electrocardiography (ECG) findings compared with angiography. The study has been important in investigating long-term predictors of cardiovascular morbidity and mortality, as well as investigating a broad spectrum of epidemiological and public health perspectives., Participants: In 1972-1975, 2014 healthy men, 40-59 years old, were enrolled in the study. Comprehensive clinical examination included an ECG-monitored exercise test at baseline and follow-ups. The cohort has been re-examined four times during 20 years. Linkage to health records and national health registries has ensured complete endpoint registration of morbidity until the end of 2006, and cancer and mortality until the end of 2017., Findings to Date: The early study results provided new evidence, as many participants with a positive exercise ECG, but no chest pain ('silent ischaemia'), did not have significant coronary artery stenosis after all. Still, they were over-represented with coronary disease after years of follow-up. Furthermore, participants with the highest physical fitness had lower risk of cardiovascular disease, and the magnitude of blood pressure responses to moderate exercise was shown to influence the risk of cardiovascular disease and mortality. With time, follow-up data allowed the scope of research to expand into other fields of medicine, with the aim of investigating predictors and the importance of lifestyle and risk factors., Future Plans: Recently, the Oslo Ischaemia Study has been found worthy, as the first scientific study, to be preserved by The National Archives of Norway. All the study material will be digitised, free to use and accessible for all. In 2030, the Oslo Ischaemia Study will be linked to the Norwegian Cause of Death Registry to obtain complete follow-up to death. Thus, a broad spectrum of additional opportunities opens., Competing Interests: Competing interests: JB is an epidemiologist employed by AstraZeneca. SEK has within the past 3 years received ad hoc lecture honoraria from Getz, Intas, Merck KGaA and Sanofi., (© Author(s) (or their employer(s)) 2021. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

The steep increase in incidence of cutaneous malignant melanoma in white populations mainly applies to thin lesions with good survival suggesting overdiagnosis. Based on population-based cancer registries (CRs), we have investigated changes in aggressive melanoma, selecting only cases who died within 1 or 3 years after diagnosis in 11 European countries between 1995 and 2012. Trends in fatal cases were analysed by period of diagnosis, sex, tumour thickness, histologic subtype of the lesion, tumour site and CR with a multivariate generalised linear mixed effects model, where geographical area was considered as a random effect. We collected data on 123 360 invasive melanomas, with 5133 fatal cases at 1 year (4%) and 12 330 (10%) at 3 years. The number of fatal cases showed a 16% decrease at 1 year and 8% at 3 years between the first (1995-2000) and the last (2007-2012) period. The highest proportion of fatal cases was seen for men, older age (≥65 years), thick lesions (>1 mm), nodular melanoma, melanoma on the trunk and for poorly documented cases, lacking information about thickness and histologic subtype. The mixed-effects model showed a remarkable variability among European countries. The majority of registries showed a decreasing trend in fatal cases, but a few registries showed an opposite pattern. Trends in fatal melanoma cases, highlighting real changes in risk not related to overdiagnosis, showed a decrease in most European countries, with a few exceptions. Stronger efforts for early detection could lead to a more efficient treatment of melanoma in general., (© 2021 UICC.)

Background: Increased risk of cutaneous melanoma and squamous cell carcinoma (SCC) has been reported among petroleum workers, but few studies include females, exposure data on ultraviolet radiation (UVR), and potential confounding factors. We aimed to examine UVR exposure in relation to risk of melanoma and SCC among male and female offshore petroleum workers. We also examined the association between UVR exposure and melanoma (Breslow) thickness., Methods: The Norwegian Offshore Petroleum Workers (NOPW) cohort (n = 27,917) holds information on sunbathing, indoor tanning, sunburns, sunscreen use, and other lifestyle factors recorded in 1998. Linkage to the Cancer Registry of Norway gave information on cancer diagnosis through 2017. We used Cox and logistic regression to estimate hazard ratios (HRs) of skin cancer and odds ratios (OR) of thick (≥1 mm) melanomas, respectively, with 95% confidence intervals (CIs)., Results: Melanoma risk increased with increasing frequency of sunbathing after age 20 (p trend  = 0.031), sunburn average intensity (p trend  = 0.028), and sunscreen use (HR = 2.16; 95% CI: 1.42 -3.27 for almost always vs. never/rarely). The risk of thick melanoma was inversely associated with sunbathing frequency after age 20 (OR = 0.38; 95% CI: 0.16 - 0.90 for ≥4 weeks/year vs. 1 week/year). SCC risk increased with increasing frequency of indoor tanning after age 20 (HR = 2.72; 95% CI: 1.22 - 6.05 for ≥3 times/months vs. never), sunburn average intensity (p trend  < 0.001), and sunscreen use (p trend  < 0.001)., Conclusions: Our results support associations between UVR exposure and skin cancer risk in male and female offshore petroleum workers. This occupational group may be especially relevant for targeted sun protection advice., (© 2021 The Authors. American Journal of Industrial Medicine Published by Wiley Periodicals LLC.)

Background: High circulating levels of vitamin D (25(OH)D) are suggested to reduce the risk of urinary bladder cancer (BC), but the evidence is weak, and several studies lack sufficient adjustment for potential confounders (e.g., smoking, body mass index (BMI), and physical activity). Moreover, few studies have investigated the role of vitamin D-binding protein (DBP) in this context. We conducted a matched nested case-control study including 378 cases and 378 controls within the Norwegian population-based Janus cohort, using serum collected 5-41 years prior to diagnosis, to study 25(OH)D and BC risk, by taking circulating DBP into account., Methods: Cox regression models were used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs), for 25(OH)D, DBP, and the molar ratio of 25(OH)D:DBP, an estimate of unbound (free) 25(OH)D levels. We adjusted for smoking (status and pack-years), BMI, physical activity, education and (mutually) for 25(OH)D and DBP. Restricted cubic splines were employed to examine nonlinear associations., Results: High optimal levels of circulating 25(OH)D (≥100 nmol/L) (HR 0.35, 95% CI 0.19-0.64) were associated with decreased BC risk, when compared with insufficient concentrations (50-74 nmol/L). This association was less pronounced for optimal levels (75-99 nmol/L) (HR = 0.69, 95% CI 0.47-1.01). Moreover, estimated free 25(OH)D, was associated with decreased BC risk for molar ratio 17-21 (HR 0.66, 95% CI 0.44-0.97) and ≥22 (HR 0.50, 95% CI 0.29-0.82), compared to molar ratio 11-16. The HR function for BC risk was not linear, rather reversed u-shaped, with the highest HR at 62.5 nmol/L and 13.5 molar ratio, respectively., Conclusion: High levels of total and estimated free 25(OH)D were associated with reduced risk of BC, compared with insufficient concentrations. DBP was not associated with BC risk. We did not observe any impact of DBP or any of the studied lifestyle factors on the association between 25(OH)D and BC., (© 2021 The Authors. Cancer Medicine published by John Wiley & Sons Ltd.)

Patients' phenotypic characteristics might be associated with melanoma aggressiveness, but the evidence is scarce. This study examined the associations be-tween pigmentary characteristics, naevi and melanoma thickness. Data from the Norwegian Women and Cancer (NOWAC) study were analysed. By 2014, 1,243 women were diagnosed with a primary melanoma, and 1,140 had information on thickness. Using ordinal logistic regression models, the probability of being diagnosed with a specific thickness category was calculated by pigmentary score and naevi. Fair pigmentary score was associated with thinner trunk melanomas (probabilities of being diagnosed with a tumour ≤1.0 mm thickness were 74%, 66%, and 51% for fair, medium and dark pigmentary scores, respectively), but not the other sites. High number of naevi was associated with thicker nodular melanoma (NM) but not with super-ficial spreading melanoma. These findings suggest the need for greater overall vigilance and skin checks among women with fair pigmentary score. The association between naevi and NM suggest possible biological mechanisms.

Background: Serum potassium levels have been positively associated with cardiovascular mortality, but little is known about the association with cancer mortality and death due to other causes. We examined whether serum levels of potassium were associated with long-term mortality in a healthy cohort., Methods: Oslo Ischemia Study invited 2341 initially healthy men aged 40-59 years with no use of medication to a comprehensive health survey in 1972. Fasting serum level of potassium (mmol/L) was ascertained at baseline for 1989 men. We have complete follow-up for death throughout 2017. Cox proportional hazard models were used to calculate hazard ratios (HRs) with 95% confidence intervals (CIs) and adjusted for multiple confounders., Results: After a median follow-up of 30 years (interquartile range 21.2-38.7), 1736 deaths were observed, of which 494 were cancer deaths, 688 cardiovascular deaths, and 536 deaths related to other causes. Restricted cubic spline analysis showed that potassium level was linearly and positively associated with long-term cancer mortality; HR per mmol/L 1.8, 95% CI 1.4-2.4. Compared with low levels of potassium (≤ 4.0 mmol/L), men with high levels (≥4.6 mmol/L) showed a significantly 78% higher risk of cancer death. A positive linear association was found for all-cause mortality (HR per mmol/L 1.6, 95% CI 1.4-1.8), and for cardiovascular (HR per mmol/L 1.4, 95% CI 1.1-1.7) and other cause mortality (HR per mmol/L 1.7, 95% CI 1.3-2.2)., Conclusions: These findings suggest that serum potassium level appears to predict long-term mortality in healthy middle-aged men, and it might imply future surveillance strategies for individuals with high serum potassium levels.

In Norway, nodular melanoma is the most fatal melanoma subtype and superficial spreading melanoma the most common, indicating diagnostic challenges. The aim of this study was to assess the clinical suspicion sensitivity of nodular melanoma and superficial spreading melanoma, by diagnosing physician, using randomly selected 100 nodular melanomas and 100 superficial spreading melanomas from the Norwegian Melanoma Registry, diagnosed in 2014 to 2015. Information about suggested diagnoses and diagnosing physician was collected from pathology request forms. Suspicion sensitivity was defined as the proportion (%) of cases with "melanoma" as a suggested diagnosis, estimated with 95% confidence interval (95% CI). Most melanomas (74.5%) were diagnosed by non-dermatologists, with a suspicion sensitivity of 23% (95% CI 15-34) for nodular melanoma and 24% (95% CI 16-35) for superficial spreading melanoma. Corresponding estimates for dermatologists were 50% (95% CI 32-68) and 96% (95% CI 80-99), respectively (pinteraction=0.007). The low suspicion sensitivity for both subtypes among non-dermatologists calls for educational efforts.

Previous studies of serum 25-hydroxyvitamin D (25(OH)D) in relation to melanoma have shown conflicting results. We conducted a nested case-control study of 708 cases and 708 controls, using prediagnostically collected serum, to study 25(OH)D and melanoma risk in the population-based Janus Serum Bank Cohort. Stratified Cox regression was used to estimate hazard ratios (HRs) with 95% confidence intervals (CIs) adjusted for ultraviolet radiation (UVR) indicators and stratified by ambient UVB of residence and body mass index (BMI). Non-linear associations were studied by restricted cubic splines. Missing data were handled with multiple imputation by chained equations. We found an HR of melanoma risk of 1.01 (95% CI: 0.99, 1.04) and an HR imputed of 1.02 (95% CI: 1.00, 1.04) per 5-nmol/L increase. The spline model showed exposure-risk curves with significantly reduced melanoma risk between 60 and 85 nmol/L 25(OH)D (reference 50 nmol/L). Non-significant J-shaped curves were found in sub-analyses of subjects with high ambient UVB of residence and of subjects with BMI < 25 kg/m 2 . Our data did not yield persuasive evidence for an association between 25(OH)D and melanoma risk overall. Serum levels within the medium range might be associated with reduced risk, an association possibly mediated by BMI.

Background: Ovarian cancer is associated with high serum calcium and low serum albumin in clinical and epidemiologic studies. Whether high calcium and low albumin predispose to ovarian cancer or reflect existing cancer is unclear., Objective: Test the hypothesis that serum calcium increases and serum albumin decreases in women who develop ovarian cancer., Methods: Two hundred and four women donated sera to the Janus Serum Bank in Norway pre- and post-diagnosis of ovarian cancer, donations separated by approximately 14 years. We measured calcium and albumin in these sera and calculated the albumin-corrected calcium. Sera were adjusted for patient age and storage time., Results: Post-diagnosis, mean age- and storage-adjusted calcium increased, from 2.53 to 2.68 mmol/L (p < .001). Mean age- and storage-adjusted, albumin-corrected calcium increased from 2.3 to 2.7 mmol/L (p < .001). Conversely, mean age- and storage-adjusted albumin decreased, from a mean of 51.3 to 40.9 g/L (p < .001). Significant changes were observed in women with early stage and metastatic cancer., Conclusions: These data support the hypothesis that calcium and albumin are serum biomarkers of extant ovarian cancer. Longitudinal changes in calcium and albumin may be useful in ovarian cancer early detection., Competing Interests: Declaration of Competing Interest GGS is an inventor on a US patent on the detection of ovarian cancer that involves calcium and albumin. No potential conflicts were disclosed by the other authors., (Copyright © 2020 The Authors. Published by Elsevier Inc. All rights reserved.)

A number of lifestyle associated factors, such as high body mass index (BMI), low physical activity, and related metabolic disorders, are associated with increased risk of cancer at several sites. For urinary bladder cancer (BC), such studies show inconsistent results, which could result from inadequate adjustment for smoking and occupational exposure. In the population-based Janus Cohort (n = 292 851), we investigated the independent and combined impact of BMI, physical activity, blood pressure, and blood lipids on the risk of BC, by thorough adjustment for smoking and potential occupational exposure. We used cox proportional hazard regression to estimate hazard ratios (HRs) with 95% confidence intervals (CIs) for the associations between the lifestyle associated factors and BC risk. The associations observed were dependent on smoking status and gender. Among men, diastolic blood pressure (DBP) (HR 1.07, 95% CI 1.02-1.12) and systolic blood pressure (SBP) (HR 1.04, 95% CI 1.01-1.07) were positively associated with BC risk. Stratification by smoking status revealed a positive association between DBP and BC risk in never smokers (HR 1.14, 95% CI 1.00-1.30), while no association was seen for current and former smokers. A risk score, integrating information across the lifestyle factors was positively associated with BC risk in men (p trend  = 0.043). In women, physical activity was associated with a decreased BC risk, but only among never smokers (HR 0.65, 95% CI 0.45-0.94). In conclusion, relations between lifestyle associated factors and BC risk were most evident in never smokers, suggesting that smoking dominates the relation in current smokers., (© 2020 The Authors. Cancer Medicine published by John Wiley & Sons Ltd.)