Jo Steinson Stenehjem

Benzene exposure and risk of lymphohaematopoietic cancers in 25,000 offshore oil industry workers.

Background:The aim of this work was to examine the risk of lymphohaematopoietic (LH) cancer according to benzene exposure among offshore workers.Methods:Cancer registry data were used to identify 112 cancer cases diagnosed during 1999–2011 in a cohort of 24 917 Norwegian men reporting offshore work between 1965 and 1999. Analyses were conducted according to a stratified case–cohort design with a reference subcohort of 1661 workers. Cox regression was used to estimate hazard ratios with 95% confidence intervals, adjusted for other benzene exposure and smoking.Results:Most workers were exposed to benzene for <15 years. The upper range values of average intensity and cumulative exposure were estimated to 0.040 p.p.m. and 0.948 p.p.m.-years, respectively. Risks were consistently elevated among exposed workers for all LH cancers combined and for most subgroups, although case numbers were small and yielded imprecise risk estimates. There was evidence of dose-related risk patterns according to cumulative exposure for acute myeloid leukaemia (AML), multiple myeloma (MM) (P trends 0.052 and 0.024, respectively), and suggestively so for chronic lymphocytic leukaemia (CLL) according to average intensity (P trend 0.094).Conclusions:Our results support an association between cumulative and intensity metrics of low-level benzene exposure and risk for AML, MM, and suggestively for CLL.

Cancer incidence among 41 000 offshore oil industry workers

BACKGROUND Cancer incidence among Norwegian offshore oil industry workers has been studied in two equally sized cohorts of 28000 workers, in a survey-based cohort study followed 1999-2005 and a register-based cohort study followed 1981-2003. AIMS To determine the overall cancer incidence in both cohorts merged, with an extended follow-up. METHODS The merged cohort yielded 41,140 individuals followed for cancer diagnoses 1999-2009. Standardized incidence ratios (SIRs) with 95% confidence intervals (CIs) were computed by gender and by period of first employment using cancer registry data. RESULTS Among female workers, the total number of cancers was slightly higher than expected (SIR 1.17, 95% CI 1.02-1.34), and excesses of acute myeloid leukaemia (AML) (SIR 5.29, 95% CI 1.72-12), malignant melanoma (SIR 2.13, 95% CI 1.41-3.08) and lung cancer (SIR 1.69, 95% CI 1.03-2.61) were observed. Among male workers, the total number of cancer cases was close to that expected (SIR 1.03, 95% CI 0.99-1.08), but cases of pleural cancer (SIR 2.56, 95% CI 1.58-3.91) and bladder cancer (SIR 1.25, 95% CI 1.05-1.49) were higher than expected. Among male workers first employed before 1986, the numbers of observed cancer cases were higher than expected for most sites, while this was not evident among those employed later. CONCLUSIONS Further studies with exposure data and confounder control are needed to address whether the observed excesses of pleural cancer and AML can be attributed to offshore work.

Cardiorespiratory fitness in long-term lymphoma survivors after high-dose chemotherapy with autologous stem cell transplantation

Background:Cardiorespiratory fitness as measured by peak oxygen consumption (VO2peak) is a strong predictor of longevity and may be compromised by anticancer therapy, inactivity, and smoking. We compared VO2peak among lymphoma survivors (LSs) with reference data from healthy sedentary subjects, after a 10.2-year (mean) follow-up post high-dose chemotherapy with autologous stem cell transplantation (HDT-ASCT). We further examined the association between VO2peak and treatment, physical activity, smoking, pulmonary, and cardiac function.Methods:Lymphoma survivors treated with HDT-ASCT in Norway 1987–2008 were eligible. VO2peak was assessed by cardiopulmonary exercise testing. Pulmonary function testing and echocardiography were also conducted. Data on treatment, physical activity, and smoking were collected from hospital records and questionnaires. VO2peak was compared with age–sex predicted reference data. Linear regression was used to associate clinical factors with VO2peak cross-sectionally.Results:A total of 194 LSs without heart failure were studied. Mean VO2peak was 4.5% and 7.7% below norms in females and males, respectively. Twenty-two percent had impaired (<80% predicted) VO2peak. Decreasing VO2peak was associated with impaired diffusion capacity and current smoking, while physical activity level and VO2peak were positively associated.Conclusion:We suggest increased attention towards physical activity counseling and smoking cessation advice to preserve cardiorespiratory fitness in LSs after HDT-ASCT. Patients with impaired diffusion capacity may benefit from subsequent monitoring to detect pulmonary vascular diseases.

Self-reported Occupational Exposures Relevant for Cancer among 28,000 Offshore Oil Industry Workers Employed between 1965 and 1999

The objective of this study was to examine self-reported frequency of occupational exposure reported by 28,000 Norwegian offshore oil workers in a 1998 survey. Predictors of self-reported exposure frequency were identified to aid future refinements of an expert-based job-exposure-time matrix (JEM). We focus here on reported frequencies for skin contact with oil and diesel; exposure to oil vapor from shaker, to exhaust fumes, vapor from mixing chemicals used for drilling, natural gas, chemicals used for water injection and processing, and to solvent vapor. Exposure frequency was reported by participants as the exposed proportion of the work shift, defined by six categories, in their current or last position offshore (between 1965 and 1999). Binary Poisson regression models with robust variance were used to examine the probabilities of reporting frequent exposure (≥¼ vs. <¼ of work shift) according to main activity, time period, supervisory position, type of company, type of installation, work schedule, and education. Holding a non-supervisory position, working shifts, being employed in the early period of the offshore industry, and having only compulsory education increased the probability of reporting frequent exposure. The identified predictors and group-level patterns may aid future refinement of the JEM previously developed for the present cohort.

A protocol for prospective studies of 25-hydroxyvitamin D, leptin and body mass index in relation to cutaneous melanoma incidence and survival

Introduction The incidence and mortality rates of cutaneous melanoma (CM) are increasing among fair-skinned populations worldwide. Ultraviolet radiation (UVR) is the principal risk factor for CM, but is also the main source of 25-hydroxyvitamin D (25(OH)D), which has been associated with reduced risk and better prognosis of some cancer types. However, both low and high 25(OH)D levels have been associated with increased risk of CM. Obesity as measured by body mass index (BMI) is associated with risk of several cancers and has also been suggested as a risk factor for CM, and may also be related to insufficient 25(OH)D and/or high leptin levels. Moreover, contracting a CM diagnosis has been associated with increased risk of developing second cancer. We aim to study whether low prediagnostic serum levels of 25(OH)D, high prediagnostic levels of BMI and high serum leptin levels influence CM incidence, Breslow thickness and CM mortality, and risk of second cancer and survival after a CM diagnosis. Methods and analysis Cohort and nested case–control studies will be carried out using the population-based Janus Serum Bank Cohort (archival prediagnostic sera, BMI, smoking and physical activity), with follow-up from 1972 to 2014. Additional data will be received from the Cancer Registry of Norway, the national Cause of Death Registry, Statistics Norway (education and occupation) and exposure matrices of UVR. Time-to-event regression models will be used to analyse the cohort data, while the nested case–control studies will be analysed by conditional logistic regression. A multilevel approach will be applied when incorporating group-level data. Ethics and dissemination The project is approved by the Regional Committee for Medical Research Ethics and is funded by the Norwegian Cancer Society. Results will be published in peer-reviewed journals, at scientific conferences and in the news media.

Anthropometric factors and cutaneous melanoma: Prospective data from the population-based Janus Cohort

The aim of the present study was to prospectively examine risk of cutaneous melanoma (CM) according to measured anthropometric factors, adjusted for exposure to ultraviolet radiation (UVR), in a large population‐based cohort in Norway. The Janus Cohort, including 292,851 Norwegians recruited 1972–2003, was linked to the Cancer Registry of Norway and followed for CM through 2014. Cox regression was used to estimate hazard ratios (HRs) of CM with 95% confidence intervals (CIs). Restricted cubic splines were incorporated into the Cox models to assess possible non‐linear relationships. All analyses were adjusted for attained age, indicators of UVR exposure, education, and smoking status. During a mean follow‐up of 27 years, 3,000 incident CM cases were identified. In men, CM risk was positively associated with body mass index, body surface area (BSA), height and weight (all ptrends < 0.001), and the exposure‐response curves indicated an exponential increase in risk for all anthropometric factors. Weight loss of more than 2 kg in men was associated with a 53% lower risk (HR 0.47, 95% CI: 0.39, 0.57). In women, CM risk increased with increasing BSA (ptrend = 0.002) and height (ptrend < 0.001). The shape of the height‐CM risk curve indicated an exponential increase. Our study suggests that large body size, in general, is a CM risk factor in men, and is the first to report that weight loss may reduce the risk of CM among men.

Ultraviolet radiation and skin cancer risk in offshore workers

Background Excess skin cancer mortality and incidence have been reported among both land-based and offshore petroleum workers. The association between skin cancer and ultraviolet radiation (UVR) exposure has not been examined in these workers, although they have long off-duty periods and high average income that may allow travelling to sunny destinations. In addition, they have access to solariums free of charge on many accommodation platforms. Aims To prospectively examine risk of incident cutaneous melanoma (CM) and non-melanoma skin cancer (NMSC), according to sun-tanning habits with adjustment for aromatic hydrocarbon exposure. Methods A cohort of men employed offshore from 1965 to 1999 was linked through the Cancer Registry of Norway 1999-2012. Cox regression adapted to a stratified case-cohort design was used to estimate hazard ratios with 95% confidence intervals. Results The cohort included 24917 men. During 13.5 years of follow-up, 112 CMs and 70 NMSCs occurred. A positive dose-response relationship was seen between sunburn frequency and risk of CM (Ptrend < 0.05) and NMSC (Ptrend < 0.01). Solarium use both before and after age 20 was related to increased risk of NMSC. Sunscreen use was associated with increased risk of NMSC (Ptrend < 0.001). Conclusions UVR exposure seems to be a significant contributor to the elevated risk of skin cancer observed in North Sea offshore workers. The positive association between solarium use and NMSC risk adds to the growing body of literature on artificial UV devices as carcinogenic.

Diffusing capacity impairment is prevalent in long-term lymphoma survivors after high-dose therapy with autologous stem cell transplantation

Diffusing capacity impairment is prevalent in long-term lymphoma survivors after high-dose therapy with autologous stem cell transplantation

Anthropometric factors and Breslow thickness

Melanoma is the most rapidly increasing cancer form in Norway, and in 2016, 2114 men and women were diagnosed with the disease. This form of cancer is often diagnosed at an early stage, and if you follow changes in your skin you will be able to detect the cancer at an early stage. Melanoma with metastasis (spreading elsewhere in the body), however, is a serious disease that is difficult to treat, and more than 300 people die in Norway from melanoma each year. The thickness of the tumour (called Breslow thickness) is an important factor for survival after melanoma; those with a thin tumour at diagnosis live longer than those with a thick tumour. In a new Norwegian study, researchers explored associations between certain factors (called anthropometric factors ‐ such as body mass index (BMI), body surface area (BSA), height, weight and weight change) and Breslow thickness, overall and by anatomical site and histological subtype (type of melanoma). Nearly 300,000 Norwegian men and women who were enrolled into a study group called the Janus population‐based cohort 1972–2003 were followed for melanoma. By 2014, 2570 cases of melanoma with information on tumour thickness were identified. This large case‐series of incident melanomas, demonstrated positive associations between BMI, BSA, weight and Breslow thickness, and showed that Breslow thickness increased with increasing BMI, BSA and weight, before levelling off or declining at high values, suggesting that behavioural or other mechanisms apply at high values.

Anthropometric factors and Breslow thickness: prospective data on 2570 cases of cutaneous melanoma in the population-based Janus Cohort

Breslow thickness is the most important prognostic factor of localized cutaneous melanoma (CM), but associations with anthropometric factors have been sparsely and incompletely investigated.