Lifelong differences in cancer incidence and mortality between subgroups of similar socioeconomic status in the Royal Norwegian Navy.

OBJECTIVES: In a previous cohort study of 28 300 Navy servicemen, vessel crews showed higher cancer incidence and mortality than did land-based personnel. We have extended the follow-up to look for changes in cancer risk, and to explore temporal trends in cancer incidence and cancer mortality during more than six decades of follow-up. METHODS: Cancer incidence and total cancer mortality were compared with the general population by calculating standardised ratios (standardised incidence ratios (SIRs), standardised mortality ratios) for the entire follow-up, with temporal trends through seven consecutive 10-year time spans from individual entry to follow-up. Rates were compared between the subgroups using Poisson regression, expressed as rate ratios (RRs). RESULTS: Cancer incidence in Navy servicemen suggested a healthy soldier effect limited to the first three decades of follow-up and confined to land-based personnel. Overall, vessel crews showed 13% higher cancer incidence and 36% higher cancer mortality than other Navy servicemen. Some of the differences may be explained by a higher risk in vessel crews of cancers known to have less than 25% 5-year relative survival (RR=1.71), such as cancers of the lung, liver, pancreas and mesothelioma. CONCLUSION: Through most of the observation time, vessel crews had an overall cancer SIR that was higher than that of land-based personnel. Much of this excess involved cancers with a generally poor prognosis, linked to lifestyle and work environment. The contrasts in cancer incidence and mortality between the two subgroups of Navy servicemen persisted through more than six decades.

Temporal trends in the healthy soldier effect in a cohort of Royal Norwegian Navy servicemen followed for 67 years.

OBJECTIVES: To investigate temporal trends in the 'healthy soldier effect' (HSE) among 28 300 Royal Norwegian Navy servicemen who served during 1950-2004. METHODS: Standardised mortality ratios (SMRs) for all causes, diseases and external causes were calculated from national rates for the entire study period (1951-2017), and for seven successive follow-up periods after the first recorded day of Naval service, for the overall cohort and for two subgroups: land-based personnel and vessel crews. Poisson regression, expressed as rate ratios, was used to compare all-cause mortality between the subgroups. RESULTS: In the overall cohort, SMRs for all-cause mortality increased steadily during the first six 10-year follow-up periods, from 0.52 to 0.94, which was still lower than national rates. After 60 years, the lower mortality compared with national rates was no longer statistically significant (SMR=0.93). Low non-neoplastic disease mortality contributed most to the longevity of the HSE. For neoplastic diseases, there was a mortality deficit only for the first and third 10-year follow-up periods. External-cause mortality rose to national rates after 40 years. An HSE was present among vessel crews, but their total mortality rate was 24% higher than that among land-based personnel, who also showed a longer-lasting HSE. CONCLUSIONS: The HSE eroded gradually over time but was still present at 60 years of follow-up for all-cause mortality. The effect was strongest and most long-lived for non-neoplastic disease, lasted up to 40 years for external causes, and was relatively short for cancers. Land-based personnel showed stronger and longer-lasting HSE than vessel crews.

External-cause mortality among 21 609 Norwegian male military peacekeepers deployed to Lebanon between 1978 and 1998.

OBJECTIVE: To investigate external-cause mortality among 21 609 Norwegian male military peacekeepers deployed to Lebanon during 1978-1998. METHODS: The cohort was followed from the 1st day of deployment through 2013, and mortality during deployment and post discharge was assessed using SMRs calculated from national rates in Norway. Poisson regression was used to see the effect of high-conflict versus low-conflict exposure. RESULTS: For the total cohort, external-cause mortality was within expected values during deployment (SMR=0.80) and post discharge (SMR=1.05). In the low-conflict exposure group, a lower mortality from all external causes (SMR=0.77), transport accidents (SMR=0.55) and accidental poisoning (SMR=0.53) was seen. The high-conflict exposure group showed an elevated mortality from all external causes (SMR=1.20), transport accidents (SMR=1.51) and suicide (SMR=1.30), but these risks were elevated only during the first 5 years after discharge. This group also showed elevated mortality from all external causes (rate ratio, RR=1.49), and for transport accidents (RR=3.30) when compared with the low-conflict exposure group. CONCLUSIONS: Overall external-cause mortality among our peacekeepers was equal to national rates during deployment and post discharge. High-conflict exposure was associated with elevated mortality from all external causes, transport accidents and suicide during the first 5 years after discharge from service.

Social and life skills in adolescents who have self-harmed: analysis of survey responses from a national sample of adolescents in Norway.

OBJECTIVE: Social and life skills (SLS) may be important in the prevention and treatment of self-harm, but few studies have described this relationship. We examined three components of SLS in adolescents who reported self-harm that was, according to themselves, diagnosed by a clinician. DESIGN: Cross-sectional. SETTING: National screening prior to military service. PARTICIPANTS: 176 284 residents of Norway born in 1999-2001 received a declaration of health. We included 171 486 individuals (84 153 (49%) women and 87 333 (51%) men) who were 17 (n=1 67 855) or 18 years of age (n=3631) when they completed the declaration. OUTCOME MEASURE: The main outcome was clinically diagnosed self-harm, defined as self-harm that the adolescents themselves stated had been diagnosed by a clinician. Components of SLS were social interactions; coping strategies; and emotional regulation/aggression. The association between SLS and self-reported clinically diagnosed self-harm was assessed in hierarchical multiple regression models controlling for sex; school absence; and feelings of emotional pain. RESULTS: Three percent (n=5507) of the adolescents reported clinically diagnosed self-harm. The three components of SLS together added little to the prediction of clinically diagnosed self-harm (∆R2=0.02). After controlling for school absence and emotional pain, emotional regulation/aggression was the only SLS-component that was independently associated with clinically diagnosed self-harm (OR 1.33, 95% CI 1.31 to 1.36). The young men who said they had been clinically diagnosed for self-harm scored slightly worse on social interactions (Hedge's g (g) = -0.13, p<0.001) and emotional regulation/aggression (g = -0.18, p<0.001) than the young women in this group. CONCLUSION: Young women and young men who reported clinically diagnosed self-harm had more problems with emotional regulation/aggression than other adolescents, but did not have worse social interactions or coping strategies.

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.

A 5-Year Continued Follow-up of Cancer Risk and All-Cause Mortality Among Norwegian Military Peacekeepers Deployed to Kosovo During 1999-2016.

INTRODUCTION: In 2012, Norwegian news media reported on cases of brain cancer among Norwegian peacekeeping troops who served in Kosovo, allegedly caused by exposure to depleted uranium fired during airstrikes before the peacekeepers arrived in 1999. A first study followed 6076 military men and women with peacekeeping service in Kosovo during 1999-2011 for cancers and deaths throughout 2011. The study did not support to the idea that peacekeeping service in Kosovo could lead to increased risk of brain cancer or other cancers. However, the average time of follow-up (10.6 years) was rather short for cancer development; therefore the aim of the present study was to evaluate cancer risk and general mortality in an updated cohort after 5 years of additional follow-up. MATERIALS AND METHODS: The updated cohort consisted of 6,159 peacekeepers (5,884 men and 275 women) who served in Kosovo during 1999-2016 and were followed for cancer incidence and mortality from all causes combined throughout 2016. We calculated standardized incidence ratios (SIR) for cancer and standardized mortality ratios (SMR) from national population rates. Poisson regression was used to assess the effect of length of service (<1 year vs. ≥1 year) on cancer risk. RESULTS: We observed 149 cancer cases and 75 deaths in the updated cohort. Observed cancer incidence did not exceed national rates. In men, the SIR for brain cancer was 0.73 (95% confidence interval (CI) 0.32-1.44), based on eight cases, while the risk of colon cancer was lowered (SIR = 0.14, 95% CI 0.00-0.79). The Poisson regression showed no effect of service duration on all-site cancer incidence. Mortality from all causes combined was lower than expected (SMR = 0.62, 95% CI 0.49-0.78) and in accordance with a "healthy soldier effect". CONCLUSION: The extended follow-up did not give support to the suggestion that peacekeeping service in Kosovo could lead to increased risk of cancer.

Cancer incidence and all-cause mortality among civilian men and women employed by the Royal Norwegian Navy between 1950 and 2005.

OBJECTIVE: We aimed to investigate cancer incidence and all-cause mortality in a cohort of 8358 civilians (5134 men and 3224 women) employed by the Royal Norwegian Navy at any time between 1950 and 2005. METHODS: The cohort was followed for cancer incidence and all-cause mortality from 1960 through 2015. Standardised incidence ratios (SIR) and mortality ratios (SMR) were calculated from national rates. Separate SIRs were calculated for a subgroup of male workshop workers and another of female cleaners. RESULTS: Overall cancer incidence among men was similar to the reference rate; male breast cancer was more frequent (SIR = 3.23). Male workshop workers showed a SIR of 1.77 for stomach cancer, while their incidence of lympho-haematopoietic cancers was half that of the reference rates. Women had increased risks of overall cancer (SIR = 1.11), lung cancer (SIR = 1.35), and ovarian cancer (SIR = 1.39). Female cleaners showed a SIR of 2.33 for bladder cancer and a lowered incidence of brain cancer (SIR = 0.18). In the overall cohort, all-cause mortality was lower than expected for men (SMR = 0.92) and closer to the reference rate for women (SMR = 0.95). CONCLUSION: In men, we observed a lowered all-cause mortality and an excess of stomach cancer in workshop workers. In women, increased risks of overall cancer, lung cancer and ovarian cancer was seen. An increased risk of bladder cancer and a lowered incidence of brain cancer was observed among female cleaners.

Disease-related mortality among 21,609 Norwegian male military peacekeepers deployed to Lebanon between 1978 and 1998.

PURPOSE: Our study assessed disease-related mortality among Norwegian male military peacekeepers deployed to Lebanon during 1978-1998. METHODS: A total of 21,609 peacekeepers were followed from start of deployment through 2013. Standardized mortality ratios (SMRs) were calculated based on national rates for the overall cohort, by length of time since first deployment to Lebanon, and for service during high- and low-conflict periods. Poisson regression was used to determine the effect of conflict exposure. RESULTS: In the overall cohort, a decreased risk was seen for all-cause mortality (1213 deaths, SMR = 0.85), mortality from neoplasms (SMR = 0.89), and from non-neoplastic diseases (SMR = 0.68). Disease-related mortality was lower during the first 5 years of follow-up, while mortality from external causes was elevated. After 5 years, mortality from neoplasms and external causes were similar to national rates, but mortality from non-neoplastic diseases remained lower. The high-conflict exposure group had a two-fold increased risk of mortality from non-neoplastic diseases (rate ratio = 2.33), including ischemic heart disease (rate ratio = 2.25) compared to the low-conflict exposure group. CONCLUSIONS: We found a "healthy soldier effect" for all-cause mortality and disease-related mortality, but for neoplasms, this effect disappeared after 5 years. Conflict exposure was positively correlated with increased risk of mortality from non-neoplastic diseases.

Cancer incidence and all-cause mortality in a cohort of 21,582 Norwegian military peacekeepers deployed to Lebanon during 1978-1998.

OBJECTIVE: We investigated cancer incidence and all-cause mortality among 21,582 Norwegian male military peacekeepers deployed to Lebanon during 1978-1998. We also looked at cancer risk according to duration of service in Lebanon, in the occupational groups of cooks and mechanics, and the risk of alcohol- and smoking-related cancers among those who served during high- or low-conflict periods. METHODS: The cohort was followed for cancer incidence and all-cause mortality from 1978 through 2012. Standardised incidence ratios (SIR) for cancer and mortality ratios (SMR) were calculated from national rates for the total cohort. SIRs were calculated according to duration of service; among cooks and mechanics; and according to high- and low-conflict exposure. Poisson regression, expressed as rate ratio (RR), was used to see the effect of duration of service, and of conflict exposure. RESULTS: A decreased risk was found for cancer incidence overall (1050 cases, SIR=0.90, 95% confidence interval [CI] 0.84-0.95) and for cancers of the prostate (SIR=0.78) and skin (other than melanoma) (SIR=0.58). The incidence of rectal cancer was 73% higher in those who served for 1 year or more than in those with shorter-term service (RR=1.73, 95% CI 1.00-3.02). The cancer risk in cooks and mechanics was within expected values. The risk of lung cancer was higher in the high-conflict exposure group than in the low-conflict exposure group (RR=1.79; 95% CI 1.00-3.18). In the total cohort, all-cause mortality was lower than expected (SMR=0.83; 95% CI 0.78-0.88). CONCLUSION: We found a "healthy soldier effect" for overall cancer incidence and all-cause mortality. Service during high-conflict periods was associated with a higher risk of lung cancer than service during low-conflict periods, but this risk was in line with that of the reference population.

Cancer risk and all-cause mortality among Norwegian military United Nations peacekeepers deployed to Kosovo between 1999 and 2011.

OBJECTIVE: Media reports of leukaemia and other cancers among European United Nations (UN) peacekeepers who served in the Balkans, and a scientific finding of excess Hodgkin lymphoma among Italian UN peacekeepers who served in Bosnia, suggested a link between cancer incidence and depleted uranium (DU) exposure. This spurred several studies on cancer risk among UN peacekeepers who served in the Balkans. Although these studies turned out to be negative, the debate about possible cancers and other health risks caused by DU exposure continues. The aim of the present study was to investigate cancer incidence and all-cause mortality in a cohort of 6076 (4.4% women) Norwegian military UN peacekeepers deployed to Kosovo between 1999 and 2011. METHODS: The cohort was followed for cancer incidence and mortality from 1999 to 2011. Standardised incidence ratios for cancer (SIR) and mortality ratios (SMR) were calculated from national rates. RESULTS: Sixty-nine cancer cases and 38 deaths were observed during follow-up. Cancer incidence in the cohort was similar to that in the general Norwegian population. No cancers in the overall cohort significantly exceeded incidence rates in the general Norwegian population, but there was an elevated SIR for melanoma of skin in men of 1.90 (95% confidence interval [CI] 0.95-3.40). A fivefold increased incidence of bladder cancer was observed among men who served in Kosovo for ≥ 1 year, based on 2 excess cases (SIR=5.27; 95% CI 1.09-15.4). All-cause mortality was half the expected rate (SMR=0.49; 95% CI 0.35-0.67). CONCLUSION: Our study did not support the suggestion that UN peacekeeping service in Kosovo is associated with increased cancer risk.

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.