A systematic review of cancer risk among users of smokeless tobacco (Swedish snus) exclusively, compared with no use of tobacco.

The main objective of this systematic review was to assess cancer risk, and mortality after cancer diagnosis, for exclusive users of Swedish snus, compared with non-users of tobacco. We followed international standards for systematic reviews and graded our confidence in the risk estimates using the GRADE approach. Our search gave 2450 articles, of which 67 were assessed in full text against our inclusion criteria. Of these, 14 cohort-studies and one case-control study were included in the review. The studies investigated risk of cancer in the oral cavity or oropharynx (3 studies), esophagus (1 study), stomach (1 study), pancreas (2 studies), colorectum (2 studies), anus (1 study) and lung (1 study), as well as malignant lymphoma (1 study), leukemia and multiple myeloma (1 study), melanoma (1 study), any cancer (1 study) and mortality after cancer diagnosis (4 studies). Cancer risk could only be evaluated in men as there was a general lack of data for women. All included studies were evaluated to have a moderate risk of bias, mostly related to validity of exposure information. An increased risk of cancer of the esophagus, pancreas, stomach and rectum as well as an association between use of snus and increased mortality after a cancer diagnosis was reported. Our confidence in the various risk estimates varied from moderate through low to very low.

Are the health risks of moist oral snuff (snus) underestimated? / Er helserisikoen ved snus undervurdert?

The use of moist oral snuff (snus) has increased significantly, particularly among young adults who have not previously smoked. Snus increases the risk of cancer, cardiovascular disease, type-2 diabetes and birth defects.

Increase in curative treatment and survival of lung cancer in Norway 2001-2016.

We have studied the alterations in the use of curative treatment and the outcome for lung cancer patients in Norway 2001-2016. The Cancer Registry of Norway has a practically complete registration of all cancer diagnoses, treatments given and deaths. For the years 2001-2016, 43,137 patients were diagnosed with lung cancer. Stereotactic radiotherapy was established nationwide from 2008 and its use has increased, and in 2016, 8.8% were given this treatment. In addition 20.6% were operated and 8.5% were treated with conventional radiotherapy. Thus 37.9% of those diagnosed were treated with intention to cure, compared to 22.9% in 2001 (p < 0.0001). Further, the median survival for the whole group diagnosed with lung cancer increased from 6.0 (95% CI 5.6-6.7) months in 2001 to 11.8 (95% CI 10.9-12.7) in 2016. The 5 year survival increased from 9.4 (95% CI 8.1-10.8)% to 19.9 (95% CI 19.2-20.6)% in the same period. In 2016 the age adjusted incidence rate was 59.5 per 100,000 (Norwegian standard) and had increased significantly in both sexes. There had also been an increase in mean age at diagnosis and the proportion diagnosed in an early stage. The increase in curative treatment has been paralleled with a doubling in both the median and 5-year survival. The present results are used for surveillance and as a benchmark, and we are looking forward to reaching a proportion of 40% of patients given curative treatment.

Harmonizing work history data in epidemiologic studies with overlapping employment records.

BACKGROUND: Work history data often require major data management including handling of overlapping jobs to avoid overestimating exposure before linkage to job-exposure matrices (JEMs) is possible. METHODS: In a case-cohort study of 1825 male Norwegian offshore petroleum workers, 3979 jobs were reported (mean duration 2417 days/job; maximum 8 jobs/worker). Each job was assigned to one of 27 occupation categories. Overlapping jobs of the same category (1142 jobs) were collapsed and overlapping jobs of different categories (1013 jobs) were split. The resulting durations were weighted by a factor accounting for the number of overlapping jobs. RESULTS: Collapsing overlapping jobs within the same category resulted in 3295 jobs (mean 2629 days/job). Splitting overlapping jobs of different categories increased the number to 4239 jobs (mean 2043 days/job), while the total duration in days dropped by 10%. CONCLUSIONS: We demonstrated that overlapping employment data structures can be harmonized in a systematic and unbiased way, preparing work history data for linkage to several JEMs.

Substantial nation-wide improvement in lung cancer relative survival in Norway from 2000 to 2016.

INTRODUCTION: There have been significant changes in both diagnostic procedures and therapy for lung cancer since the beginning of the millennium. National incidence and survival data from 2000 through 2016 are studied. METHODS: National data on cancer incidence and vital status are virtually complete. Changes in incidence and survival are described by absolute numbers, percentages, and calculation of relative survival (period analysis). RESULTS: A total of 44,825 individuals were diagnosed with lung cancer in Norway in the study period. The number of incident cases increased with 49% whereas the prevalence increased with 136% from 2000 to 2016. Age-standardised rates rose markedly for women and levelled off for men. In 2016, adenocarcinoma accounted for about 50% of all lung cancers, slightly more for women than for men. The entity "NSCLC not otherwise specified" declined from 24% to 13%, and the fraction of patients with metastatic disease decreased from 54% to 46% during the period, for both sexes combined. The overall median survival time doubled for women and men, reaching 14.3 months and 11.4 months, respectively. For patients with metastatic disease, median survival time showed a small increase but remained less than 6 months. The overall 5-year relative survival increased from 16% to 26% in women and from 16% to 22% in men. The corresponding improvements for the subgroup of non-surgically treated cases with localised disease, were up from 25% to more than 40% in females, and from 10% to almost 40% in males. CONCLUSION: There have been notable changes in incidence patterns and a remarkable improvement in survival for lung cancer over the last 17 years, most markedly for patients without distant metastases at the time of diagnosis. Hopefully, survival will improve even more when immunotherapy is implemented.

Bladder cancer survival: Women better off in the long run.

AIM: Mortality among patients with bladder cancer is usually reported to be higher for women than men, but how the risk differs and why remain largely unexplained. We also described gender-specific differences in survival for patients with bladder cancer and estimated to what extent they can be explained by differences in T-stage distribution at the first diagnosis. METHODS: The present study comprised all 15,129 new cases of histologically verified invasive and non-invasive urothelial carcinoma of the urinary bladder diagnosed between 1997 and 2011 as registered in the Cancer Registry of Norway. Gender-specific excess mortality risk rates and risk ratios were calculated based on a flexible parametric relative survival model adjusting for T-stage and age, allowing the effect of gender to vary over time. We also present gender-specific relative survival curves for different T-stage patterns adjusted for age. RESULTS: Risk rates were significantly higher for women than men up to 2 years after bladder cancer diagnosis, particularly for muscle-invasive cancers. Thereafter, risk rates appeared to be higher in men. Adverse T-Stage distribution in women explained half of the unfavourable survival difference in female patients 2 years after diagnosis. CONCLUSION: The common view of worse bladder cancer prognosis in women than in men needs to be revised. Norwegian women have a less favourable prognosis solely within the first 2 years after diagnosis, particularly when diagnosed with a muscle-invasive tumour; parts of this discrepancy can be attributed to more severe initial diagnoses in women.

Lung cancer incidence associated with radon exposure in Norwegian homes. / Lungekreftforekomst knyttet til radoneksponering i norske boliger.

BACKGROUND: Radioactive radon gas is generated from uranium and thorium in underlying rocks and seeps into buildings. The gas and its decay products emit carcinogenic radiation and are regarded as the second most important risk factor for lung cancer after active tobacco smoking. The average radon concentration in Norwegian homes is higher than in most other Western countries. From a health and cost perspective, it is important to be able to quantify the risk of lung cancer posed by radon exposure. MATERIAL AND METHOD: We estimated the radon-related risk of lung cancer in Norway based on risk estimates from the largest pooled analysis of European case-control studies, combined with the hitherto largest set of data on radon concentration measurements in Norwegian homes. RESULTS: Based on these estimates, we calculate that radon is a contributory factor in 12 % of all cases of lung cancer annually, assuming an average radon concentration of 88 Bq/m3 in Norwegian homes. For 2015, this accounted for 373 cases of lung cancer, with an approximate 95 % confidence interval of 145 ­ 682. INTERPRETATION: Radon most likely contributes to a considerable number of cases of lung cancer. Since most cases of radon-associated lung cancer involve smokers or former smokers, a reduction of the radon concentration in homes could be a key measure to reduce the risk, especially for persons who are unable to quit smoking. The uncertainty in the estimated number of radon-associated cases can be reduced through a new national radon mapping study with an improved design.

Aromatic hydrocarbons and risk of skin cancer by anatomical site in 25 000 male offshore petroleum workers.

BACKGROUND: We prospectively examined skin cancer risk according to occupational exposure to aromatic hydrocarbons with adjustment for ultraviolet radiation exposure, in a cohort of 24 917 male offshore petroleum workers. METHODS: Hazard ratios (HRs) and 95% confidence intervals were estimated with Cox regression adapted to a stratified case-cohort design. RESULTS: During 13.5 years of follow-up, 112 cutaneous melanomas (CMs) and 70 non-melanoma skin cancers were identified. Increased risks of CM and of squamous cell carcinoma on the forearm and hand were seen among those ever exposed to crude oil or benzene. For skin cancers of the forearm and hand combined, cumulative and duration metrics of benzene exposure showed Ptrends of 0.031 and 0.003, respectively. CONCLUSIONS: Our results support an association between exposure to crude oil or benzene and skin cancer risk on hands and forearms among offshore petroleum workers. Dermal uptake of polycyclic aromatic hydrocarbons or benzene may explain this association.

Lung cancer ­ changes in incidence by gender, age and county of residence 1984-2013.

BACKGROUND: The Cancer Registry of Norway has reported a decline in age-standardised lung cancer rates for men and an unconfirmed levelling-off in the rate for women. This study describes the development in trends according to gender and age, nationwide as well as by county. MATERIAL AND METHOD: Data on lung cancer from the Cancer Registry of Norway and the NORDCAN website are presented as age-specific and age-standardised rates by gender and place of residence, with a main emphasis on the period 1984-2013. RESULTS: Out of 62,937 Norwegian lung cancer patients (1984-2013), altogether 63% were men. Nationally there was a decline in the rate for middle-aged men (50-69 years), but only a levelling-off in the oldest age group (≥ 70 years). For women, the rates increased in both age groups, most markedly in the oldest one. The rates for older men in the Agder, Vestfold and Finnmark counties have remained above the national average for a prolonged period, and there are only modest signs of a decline among the middle-aged. Oslo is a clear exception, with a clear and sustained decline among men in both age groups. Vest-Agder county had the highest rate for women during the last five-year period, while the rates in Oslo are now at the national average. The national rates for middle-aged women and middle-aged men are converging, intersecting each other in Akershus county. INTERPRETATION: The large differences between genders, age groups, counties and nations in terms of trends in lung cancer indicate that through preventive efforts, we might have achieved much more in a shorter time.

Association Between Prediagnostic Serum 25-Hydroxyvitamin D Concentration and Glioma.

There are no previous studies of the association between prediagnostic serum vitamin D concentration and glioma. Vitamin D has immunosuppressive properties; as does glioma. It was, therefore, our hypothesis that elevated vitamin D concentration would increase glioma risk. We conducted a nested case-control study using specimens from the Janus Serum Bank cohort in Norway. Blood donors who were subsequently diagnosed with glioma (n = 592), between 1974 and 2007, were matched to donors without glioma (n = 1112) on date and age at blood collection and sex. We measured 25-hydroxyvitamin D [25(OH)D], an indicator of vitamin D availability, using liquid chromatography coupled with mass spectrometry. Seasonally adjusted odds ratios (ORs) and 95% confidence intervals (95% CIs) were estimated for each control quintile of 25(OH)D using conditional logistic regression. Among men diagnosed with high grade glioma >56, we found a negative trend (P = .04). Men diagnosed ≤ 56 showed a borderline positive trend (P = .08). High levels (>66 nmol/L) of 25(OH)D in men >56 were inversely related to high grade glioma from ≥2 yr before diagnosis (OR = 0.59; 95% CI = 0.38, 0.91) to ≥15 yr before diagnosis (OR = 0.61; 95% CI = 0.38,0.96). Our findings are consistent long before glioma diagnosis and are therefore unlikely to reflect preclinical disease.

Cause-specific mortality and cancer incidence among 28,300 Royal Norwegian Navy servicemen followed for more than 50 years.

OBJECTIVES: The aim of this study was to examine mortality and cancer incidence in a cohort of 28,300 military servicemen known, from personnel files, to have served in the Royal Norwegian Navy during 1950-2004. METHODS: The cohort was followed from 1951-2007 for mortality and from 1953-2008 for cancer. Standardized mortality ratios (SMR) and incidence ratios (SIR) for cancer were calculated from national rates. Internal comparisons [rate ratios (RR)] were made using Poisson regression. RESULTS: Mortality for all Navy personnel was lower than expected for all causes combined (SMR 0.84) and for most disease groups and violent causes, but not for cancer mortality (SMR 1.02). Vessel crews had consistently higher SMR than land-based personnel, still with rates lower than - or close to - national ones. The relative risk between the two subgroups was in the same direction for mortality from alcohol abuse and non-malignant alcohol-related diseases (RR 1.56) and for the incidence of alcohol-related cancers (RR 1.58) and lung cancer (RR 1.65). An overall small excess in the incidence of all cancers combined for the entire cohort (SIR 1.06) was caused by prostate cancer, malignant melanoma, and non-melanoma skin cancer. An excess of bladder cancer was observed among submariners (SIR 1.53). CONCLUSION: The low all-cause mortality was in line with a "healthy soldier effect". Navy personnel had a lower-than-expected mortality from accidents and suicide. Alcohol-related diseases were more frequent among vessel crews than among land-based personnel, but largely comparable to the rates among all Norwegian men.

Asbestos-related cancers among 28,300 military servicemen in the Royal Norwegian Navy.

INTRODUCTION: This study focus on the incidence of asbestos-related cancers among 28,300 officers and enlisted servicemen in the Royal Norwegian Navy. Until 1987, asbestos aboard the vessels potentially caused exposure to 11,500 crew members. METHODS: Standardized incidence ratios (SIR) were calculated for malignant mesothelioma, lung cancer, and laryngeal, pharyngeal, stomach, and colorectal cancers according to service aboard between 1950 and 1987 and in other Navy personnel. RESULTS: Increased risk of mesothelioma was seen among engine room crews, with SIRs of 6.23 (95% CI = 2.51-12.8) and 6.49 (95% CI = 2.11-15.1) for personnel who served less than 2 years and those with longer service, respectively. Lung cancer was nearly 20% higher than expected among both engine crews and non-engine crews. An excess of colorectal cancer bordering on statistical significance was seen among non-engine crews (SIR = 1.14; 95% CI = 0.98-1.32). Land-based personnel and personnel who served aboard after 1987 had lower lung cancer incidence than expected (SIR = 0.77; 95% CI = 0.64-0.92). No elevated risk of laryngeal, pharyngeal, or stomach cancers was seen. CONCLUSION: The overall increase (65%) in mesotheliomas among military Navy servicemen was confined to marine engine crews only. The mesothelioma incidence can be taken as an indicator of the presence or absence of asbestos exposure, but it offered no consistent explanation to the variation in incidence of other asbestos-related cancers.