The role of lifestyle factors in the association between education and self-reported fibromyalgia: a mediation analysis.

BACKGROUND: Socioeconomic status as measured by education, income, or occupation, has been associated with fibromyalgia but the underlying mechanism and the role of lifestyle factors are unclear. Thus, we examine the role of modifiable lifestyle factors (body mass index, physical activity, alcohol consumption and smoking) in the association between education and self-reported fibromyalgia. METHODS: We used data from 74,157 participants in the population-based prospective Norwegian Women and Cancer (NOWAC) study. Socioeconomic position, operationalized as years of educational attainment, and lifestyle factors were assessed via self-reported questionnaires. Multiple mediation analysis was used to decompose total effects into direct and indirect effects. Estimates were reported as hazard ratios (HRs) with 95% confidence intervals (CIs). RESULTS: The cumulative incidence of fibromyalgia was 3.2% after a median follow up time of 13 years. Fibromyalgia was inversely associated with years of educational attainment for ≤ 9 years (HR = 2.56; 95% CI 2.32-2.91) and for 10-12 years (HR = 1.84; 95% CI 1.72-2.02), compared with ≥ 13 years of education. Overall, all lifestyle factors together jointly mediated 17.3% (95% CI 14.3-21.6) and 14.1% (95% CI 11.3-18.9) of the total effect for ≤ 9 years and 10-12 years of education, respectively. Smoking and alcohol consumption contributed the most to the proportion mediated, for ≤ 9 years (5.0% and 7.0%) and 10-12 years (5.6% and 4.5%) of education. CONCLUSION: The association between education and self-reported fibromyalgia was partly explained through lifestyle factors, mainly smoking and alcohol consumption.

Associations Between Self-Rated Health and Mortality in the Norwegian Women and Cancer (NOWAC) Study.

Purpose: We investigated the association between self-rated health (SRH) and cancer incidence and SRH and all-cause mortality among Norwegian women. Population and Methods: We used data from 110,104 women in the Norwegian Women and Cancer (NOWAC) cohort aged 41-70 years at baseline. We used flexible parametric survival analysis with restricted cubic splines to calculate hazard ratios (HRs) and 95% confidence intervals (CIs) for the association between SRH and mortality in the entire cohort. We employed the same method in a multistate design to assess associations between baseline SRH and 1) cancer incidence, and 2) all-cause mortality in subgroups of women who did and did not receive a cancer diagnosis during follow-up. Results: With very good SRH as reference category for all associations and median age at end of follow-up, lower SRH was associated with increased mortality (HRgood SRH 1.19, 95% CI 1.12-1.26) and HRpoor SRH 1.81, 95% CI 1.66-1.97). Lower SRH at baseline was associated with cancer incidence (HRgood SRH 1.14, 95% CI 1.08-1.20 and HRpoor SRH 1.44, 95% CI: 1.32-1.58). Poor baseline SRH was associated with increased mortality for women who received a cancer diagnosis (HRpoor SRH 1.20, 95% CI 1.04-1.39), and SRH showed a strong association with increased mortality for women who stayed cancer free (HRgood SRH 1.59, 95% CI 1.44-1.77 and HRpoor SRH 3.34, 95% CI 2.91-3.84). Conclusion: Lower SRH at baseline predicted increased cancer risk and all-cause mortality in middle-aged to older women. Poor SRH at baseline predicted all-cause mortality in women who later received a cancer diagnosis. Both good and poor SRH at baseline predicted all-cause mortality in women who stayed cancer-free, and the association was stronger for these women compared to both the entire cohort and to women who were subsequently diagnosed with cancer.

Cumulative exposure to estrogen may increase the risk of migraine in women.

BACKGROUND: Migraine is a common disorder, particularly affecting women during their reproductive years. This female preponderance has been linked to exposure to female sex hormones. METHODS: We used self-reported data from women born in 1943-1965 enrolled in the Norwegian Women and Cancer Study to examine the differences between women with migraine and women without migraine in a prospective design with respect to both endogenous and exogenous female sex hormone exposure. RESULTS: In total, 62,959 women were included in the study, of whom 24.8% reported previous migraine (n = 15,635). Using a Cox proportional hazards model, we found that higher age at menarche reduced the risk of migraine (hazards ratio (HR) = 0.96, 95% confidence interval (CI) = 0.95-0.98) and that oral contraceptive use and parity increased the risk of migraine (HR = 1.12, 95% CI = 1.06-1.18 and HR = 1.37, 95% CI = 1.29-1.46, respectively). CONCLUSIONS: Older age at menarche appears to reduce migraine risk, whereas oral contraceptive use and having children appear to increase the risk. Further research is required to investigate the causality of these associations.

Ultra-processed foods, adiposity and risk of head and neck cancer and oesophageal adenocarcinoma in the European Prospective Investigation into Cancer and Nutrition study: a mediation analysis.

PURPOSE: To investigate the role of adiposity in the associations between ultra-processed food (UPF) consumption and head and neck cancer (HNC) and oesophageal adenocarcinoma (OAC) in the European Prospective Investigation into Cancer and Nutrition (EPIC) cohort. METHODS: Our study included 450,111 EPIC participants. We used Cox regressions to investigate the associations between the consumption of UPFs and HNC and OAC risk. A mediation analysis was performed to assess the role of body mass index (BMI) and waist-to-hip ratio (WHR) in these associations. In sensitivity analyses, we investigated accidental death as a negative control outcome. RESULTS: During a mean follow-up of 14.13 ± 3.98 years, 910 and 215 participants developed HNC and OAC, respectively. A 10% g/d higher consumption of UPFs was associated with an increased risk of HNC (hazard ratio [HR] = 1.23, 95% confidence interval [CI] 1.14-1.34) and OAC (HR = 1.24, 95% CI 1.05-1.47). WHR mediated 5% (95% CI 3-10%) of the association between the consumption of UPFs and HNC risk, while BMI and WHR, respectively, mediated 13% (95% CI 6-53%) and 15% (95% CI 8-72%) of the association between the consumption of UPFs and OAC risk. UPF consumption was positively associated with accidental death in the negative control analysis. CONCLUSIONS: We reaffirmed that higher UPF consumption is associated with greater risk of HNC and OAC in EPIC. The proportion mediated via adiposity was small. Further research is required to investigate other mechanisms that may be at play (if there is indeed any causal effect of UPF consumption on these cancers).

Replacing red and processed meat with lean or fatty fish and all-cause and cause-specific mortality in Norwegian women. The Norwegian Women and Cancer Study (NOWAC): a prospective cohort study.

Nordic Nutrition Recommendations recommend reducing red and processed meat and increasing fish consumption, but the impact of this replacement on mortality is understudied. This study investigated the replacement of red and processed meat with fish in relation to mortality. Of 83 304 women in the Norwegian Women and Cancer Study (NOWAC) study, 9420 died during a median of 21·0 years of follow-up. The hazard ratios (HR) for mortality were estimated using Cox proportional hazards regression with analyses stratified on red and processed meat intake due to non-linearity. Higher processed meat (> 30 g/d), red and processed meat (> 50 g/d), and fatty fish consumption were associated with higher mortality, while red meat and lean fish consumption were neutral or beneficial. Among women with higher processed meat intake (> 30 g/d), replacing 20 g/d with lean fish was associated with lower all-cause (HR 0·92, 95 % CI 0·89, 0·96), cancer (HR 0·92, 95 % CI 0·88, 0·97) and CVD mortality (HR 0·82, 95 % CI 0·74, 0·90), while replacing with fatty fish was associated with lower CVD mortality (HR 0·87, 95 % CI 0·77, 0·97), but not with all-cause or cancer mortality. Replacing processed meat with fish among women with lower processed meat intake (≤ 30 g/d) or replacing red meat with fish was not associated with mortality. Replacing processed meat with lean or fatty fish may lower the risk of premature deaths in Norwegian women, but only in women with high intake of processed meat. These findings suggest that interventions to reduce processed meat intake should target high consumers.

Lifestyle risk factors of self-reported fibromyalgia in the Norwegian Women and Cancer (NOWAC) study.

BACKGROUND: While the aetiology of fibromyalgia syndrome (FM) remains unknown, lifestyle factors have been linked to the disorder. However, there are few studies on the association between lifestyle factors and FM, thus we examine the risk of self-reported fibromyalgia given selected lifestyle factors. METHODS: We used data from 75,485 participants in the Norwegian Women and Cancer study. Information on FM and the lifestyle factors body mass index (BMI), physical activity level, smoking status/intensity, and alcohol consumption were obtained from baseline and follow-up questionnaires. We used Cox proportional hazards model to calculate hazard ratios (HRs) with 95% confidence intervals (CIs). RESULTS: After a median follow-up time of 10 years, we observed 2,248 cases of self-reported fibromyalgia. Overweight (BMI 25-29.9 kg/m2) and obese (BMI ≥ 30 kg/m2) women had a relative risk of 1.34 (95% CI 1.21-1.47) and 1.62 (95% CI 1.41-1.87), respectively, compared to women with normal weight (BMI 18.5-24.9 kg/m2). Very low physical activity level (1-2) was associated with a 31% higher risk of self-reported fibromyalgia (HR 1.31, 95% CI 1.09-1.57) when compared to moderate physical activity level (5-6). There was a strong dose-response relationship between smoking status/intensity and self-reported fibromyalgia (p for trend < 0.001). Compared with moderate alcohol consumption (4.0-10 g/day), the risk of self-reported FM was 72% (HR 1.72; 95% CI 1.45-2.03) higher among teetotallers, and 38% (HR 1.38, 95% CI 1.23-1.54) higher among those with low consumption (0.1-3.9 g/day). CONCLUSIONS: Overweight and obesity, very low physical activity level, smoking, and alcohol consumption were associated with an increased risk of self-reported FM.

Reproductive and hormonal factors and risk of renal cell carcinoma among women in the European Prospective Investigation into Cancer and Nutrition.

BACKGROUND: Renal cell carcinoma (RCC) is twice as common among men compared with women, and hormonal factors have been suggested to partially explain this difference. There is currently little evidence on the roles of reproductive and hormonal risk factors in RCC aetiology. MATERIALS & METHODS: We investigated associations of age at menarche and age at menopause, pregnancy-related factors, hysterectomy and ovariectomy and exogenous hormone use with RCC risk among 298,042 women in the European Prospective Investigation into Cancer and Nutrition (EPIC) study. RESULTS: During 15 years of follow-up, 438 RCC cases were identified. Parous women had higher rates of RCC compared with nulliparous women (HR = 1.71, 95% CI 1.18, 2.46), and women who were older at age of first pregnancy had lower rates of RCC (30 years + vs. <20 years HR = 0.53, 95% CI 0.34, 0.82). Additionally, we identified a positive association for hysterectomy (HR = 1.43 95% CI 1.09, 1.86) and bilateral ovariectomy (HR = 1.67, 95% CI 1.13, 2.47), but not unilateral ovariectomy (HR = 0.99, 95% CI 0.61, 1.62) with RCC risk. No clear associations were found for age at menarche, age at menopause or exogenous hormone use. CONCLUSION: Our results suggest that parity and reproductive organ surgeries may play a role in RCC aetiology.

Overall lifestyle changes in adulthood are associated with cancer incidence in the Norwegian Women and Cancer Study (NOWAC) - a prospective cohort study.

BACKGROUND: Cancer is a leading cause of premature death worldwide and incidence is expected to rise in the coming decades. Many cohort studies, measuring lifestyle factors at one time-point, have observed that overall healthy lifestyles were inversely related to cancer incidence. However, there is little knowledge on the impact of lifestyle modification within adulthood. METHODS: Using the Norwegian Women and Cancer study, two repeated self-reported assessments of lifestyle behaviours were used to calculate healthy lifestyle index scores at each time-point (N = 66 233). The associations between change in healthy lifestyle index score and lifestyle-related cancer incidence, including alcohol-, tobacco-, obesity-, and reproductive-related, and site-specific breast and colorectal cancer incidence were estimated using Cox proportional hazard regression models. To assess nonlinearity in the dose-response relationships, restricted cubic spline models were used. RESULTS: Independent of baseline lifestyle, positive lifestyle changes were inversely related to the incidence of overall lifestyle-related cancers, as well as alcohol-related, tobacco-related, obesity-related, and reproductive-related cancers, but not breast and colorectal site-specific cancers. An association between lifestyle worsening and cancer incidence compared to stable lifestyle was observed. CONCLUSIONS: This study provides evidence that overall lifestyle changes among cancer-free women between the ages of 41 and 76 impact the incidence of many cancer types. Regardless of baseline lifestyle, there was a negative dose-response relationship between magnitude of positive lifestyle change and the incidence of overall lifestyle-related cancers. We observed that underlying this trend was an especially clear association between lifestyle worsening and increased risk compared to stable lifestyle. For adult women, maintaining a stable healthy lifestyle and lifestyle improvement are important for preventing the occurrence of many cancer types.

Symptoms and signs of urogenital cancer in primary care.

BACKGROUND: Urogenital cancers are common, accounting for approximately 20% of cancer incidence globally. Cancers belonging to the same organ system often present with similar symptoms, making initial management challenging. In this study, 511 cases of cancer were recorded after the date of consultation among 61,802 randomly selected patients presenting in primary care in six European countries: a subgroup analysis of urogenital cancers was carried out in order to study variation in symptom presentation. METHODS: Initial data capture was by completion of standardised forms containing closed questions about symptoms recorded during the consultation. The general practitioner (GP) provided follow-up data after diagnosis, based on medical record data made after the consultation. GPs also provided free text comments about the diagnostic procedure for individual patients. RESULTS: The most common symptoms were mainly associated with one or two specific types of cancer: 'Macroscopic haematuria' with bladder or renal cancer (combined sensitivity 28.3%), 'Increased urinary frequency' with bladder (sensitivity 13.3%) or prostatic (sensitivity 32.1%) cancer, or to uterine body (sensitivity 14.3%) cancer, 'Unexpected genital bleeding' with uterine cancer (cervix, sensitivity 20.0%, uterine body, sensitivity 71.4%). 'Distended abdomen, bloating' had sensitivity 62.5% (based on eight cases of ovarian cancer). In ovarian cancer, increased abdominal circumference and a palpable tumour also were important diagnostic elements. Specificity for 'Macroscopic haematuria' was 99.8% (99.7-99.8). PPV > 3% was noted for 'Macroscopic haematuria' and bladder or renal cancer combined, for bladder cancer in male patients. In males aged 55-74, PPV = 7.1% for 'Macroscopic haematuria' and bladder cancer. Abdominal pain was an infrequent symptom in urogenital cancers. CONCLUSIONS: Most types of urogenital cancer present with rather specific symptoms. If the GP considers ovarian cancer, increased abdominal circumference should be actively determined. Several cases were clarified through the GP's clinical examination, or laboratory investigations.

Assessment of the EarlyCDT-Lung test as an early biomarker of lung cancer in ever-smokers: A retrospective nested case-control study in two prospective cohorts.

The EarlyCDT-Lung test is a blood-based autoantibody assay intended to identify high-risk individuals for low-dose computed tomography lung cancer screening. However, there is a paucity of evidence on the performance of the EarlyCDT-Lung test in ever-smokers. We conducted a nested case-control study within two prospective cohorts to evaluate the risk-discriminatory performance of the EarlyCDT-Lung test using prediagnostic blood samples from 154 future lung cancer cases and 154 matched controls. Cases were selected from those who had ever smoked and had a prediagnostic blood sample <3 years prior to diagnosis. Conditional logistic regression was used to estimate the association between EarlyCDT-Lung test results and lung cancer risk. Sensitivity and specificity of the EarlyCDT-Lung test were calculated in all subjects and subgroups based on age, smoking history, lung cancer stage, sample collection time before diagnosis and year of sample collection. The overall lung cancer odds ratios were 0.89 (95% CI: 0.34-2.30) for a moderate risk EarlyCDT-Lung test result and 1.09 (95% CI: 0.48-2.47) for a high-risk test result compared to no significant test result. The overall sensitivity was 8.4% (95% CI: 4.6-14) and overall specificity was 92% (95% CI: 87-96) when considering a high-risk result as positive. Stratified analysis indicated higher sensitivity (17%, 95% CI: 7.2-32.1) in subjects with blood drawn up to 1 year prior to diagnosis. In conclusion, our study does not support a role of the EarlyCDT-Lung test in identifying the high-risk subjects in ever-smokers for lung cancer screening in the EPIC and NSHDS cohorts.

Mediating Role of Lifestyle Behaviors in the Association between Education and Cancer: Results from the European Prospective Investigation into Cancer and Nutrition.

BACKGROUND: Many studies have shown that socioeconomic position (SEP) is associated with the incidence of malignant tumors at different sites. This study aims to estimate the association between educational level (as proxy for SEP) and cancer incidence and to understand whether the observed associations might be partially explained by lifestyle behaviors. METHODS: The analyses were performed on data from the European Prospective Investigation into Cancer and Nutrition (EPIC) study, globally and by sex. We used Cox proportional hazards models together with mediation analysis to disentangle the total effect (TE) of educational level [measured through the Relative Index of Inequality (RII)] on cancer incidence into pure direct (PDE) and total indirect (TIE) effect, unexplained and explained by mediators, respectively. PDE and TIE were then combined to compute the proportions mediated (PM). RESULTS: After an average of 14 years of follow-up, 52,422 malignant tumors were ascertained. Low educated participants showed higher risk of developing stomach, lung, kidney (in women), and bladder (in men) cancers, and, conversely, lower risk of melanoma and breast cancer (in post-menopausal women), when compared with more educated participants. Mediation analyses showed that portions of the TE of RII on cancer could be explained by site-specific related lifestyle behaviors for stomach, lung, and breast (in women). CONCLUSIONS: Cancer incidence in Europe is determined at least in part by a socioeconomically stratified distribution of risk factors. IMPACT: These observational findings support policies to reduce cancer occurrence by altering mediators, such as lifestyle behaviors, particularly focusing on underprivileged strata of the population.

A longitudinal evaluation of alcohol intake throughout adulthood and colorectal cancer risk.

BACKGROUND: Alcohol intake is an established risk factor for colorectal cancer (CRC); however, there is limited knowledge on whether changing alcohol drinking habits during adulthood modifies CRC risk. OBJECTIVE: Leveraging longitudinal exposure assessments on alcohol intake at different ages, we examined the relationship between change in alcohol intake and subsequent CRC risk. METHODS: Within the European Prospective Investigation into Cancer and Nutrition, changes in alcohol intake comparing follow-up with baseline assessments were investigated in relation to CRC risk. The analysis included 191,180, participants and 1530 incident CRC cases, with exclusion of the first three years of follow-up to minimize reverse causation. Trajectory profiles of alcohol intake, assessed at ages 20, 30, 40, 50 years, at baseline and during follow-up, were estimated using latent class mixed models and related to CRC risk, including 407,605 participants and 5,008 incident CRC cases. RESULTS: Mean age at baseline was 50.2 years and the follow-up assessment occurred on average 7.1 years later. Compared to stable intake, a 12 g/day increase in alcohol intake during follow-up was positively associated with CRC risk (HR = 1.15, 95%CI 1.04, 1.25), while a 12 g/day reduction was inversely associated with CRC risk (HR = 0.86, 95%CI 0.78, 0.95). Trajectory analysis showed that compared to low alcohol intake, men who increased their alcohol intake from early- to mid- and late-adulthood by up to 30 g/day on average had significantly increased CRC risk (HR = 1.24; 95%CI 1.08, 1.42), while no associations were observed in women. Results were consistent by anatomical subsite. CONCLUSIONS: Increasing alcohol intake during mid-to-late adulthood raised CRC risk, while reduction lowered risk.

Cigarette Smoking and Endometrial Cancer Risk: Observational and Mendelian Randomization Analyses.

BACKGROUND: Current epidemiologic evidence indicates that smoking is associated with a lower endometrial cancer risk. However, it is unknown if this association is causal or confounded. To further elucidate the role of smoking in endometrial cancer risk, we conducted complementary observational and Mendelian randomization (MR) analyses. METHODS: The observational analyses included 286,415 participants enrolled in the European Prospective Investigation into Cancer and Nutrition and 179,271 participants in the UK Biobank, and multivariable Cox proportional hazards models were used. In two-sample MR analyses, genetic variants robustly associated with lifetime amount of smoking (n = 126 variants) and ever having smoked regularly (n = 112 variants) were selected and their association with endometrial cancer risk (12,906 cancer/108,979 controls from the Endometrial Cancer Association Consortium) was examined. RESULTS: In the observational analysis, lifetime amount of smoking and ever having smoked regularly were associated with a lower endometrial cancer risk. In the MR analysis accounting for body mass index, a genetic predisposition to a higher lifetime amount of smoking was not associated with endometrial cancer risk (OR per 1-SD increment: 1.15; 95% confidence interval: 0.91-1.44). Genetic predisposition to ever having smoked regularly was not associated with risk of endometrial cancer. CONCLUSIONS: Smoking was inversely associated with endometrial cancer in the observational analyses, although unsupported by the MR. Additional studies are required to better understand the possible confounders and mechanisms underlying the observed associations between smoking and endometrial cancer. IMPACT: The results from this analysis indicate that smoking is unlikely to be causally linked with endometrial cancer risk.

Venous Air Embolism Activates Complement C3 Without Corresponding C5 Activation and Trigger Thromboinflammation in Pigs.

Introduction: Air embolism may complicate invasive medical procedures. Bubbles trigger complement C3-mediated cytokine release, coagulation, and platelet activation in vitro in human whole blood. Since these findings have not been verified in vivo, we aimed to examine the effects of air embolism in pigs on thromboinflammation. Methods: Forty-five landrace pigs, average 17 kg (range 8.5-30), underwent intravenous air infusion for 300 or 360 minutes (n=29) or served as sham (n=14). Fourteen pigs were excluded due to e.g. infections or persistent foramen ovale. Blood was analyzed for white blood cells (WBC), complement activation (C3a and terminal C5b-9 complement complex [TCC]), cytokines, and hemostatic parameters including thrombin-antithrombin (TAT) using immunoassays and rotational thromboelastometry (ROTEM). Lung tissue was analyzed for complement and cytokines using qPCR and immunoassays. Results are presented as medians with interquartile range. Results: In 24 pigs receiving air infusion, WBC increased from 17×109/L (10-24) to 28 (16-42) (p<0.001). C3a increased from 21 ng/mL (15-46) to 67 (39-84) (p<0.001), whereas TCC increased only modestly (p=0.02). TAT increased from 35 µg/mL (28-42) to 51 (38-89) (p=0.002). ROTEM changed during first 120 minutes: Clotting time decreased from 613 seconds (531-677) to 538 (399-620) (p=0.006), clot formation time decreased from 161 seconds (122-195) to 124 (83-162) (p=0.02) and α-angle increased from 62 degrees (57-68) to 68 (62-74) (p=0.02). In lungs from pigs receiving air compared to sham animals, C3a was 34 ng/mL (14-50) versus 4.1 (2.4-5.7) (p<0.001), whereas TCC was 0.3 CAU/mL (0.2-0.3) versus 0.2 (0.1-0.2) (p=0.02). Lung cytokines in pigs receiving air compared to sham animals were: IL-1ß 302 pg/mL (190-437) versus 107 (66-120), IL-6 644 pg/mL (358-1094) versus 25 (23-30), IL-8 203 pg/mL (81-377) versus 21 (20-35), and TNF 113 pg/mL (96-147) versus 16 (13-22) (all p<0.001). Cytokine mRNA in lung tissue from pigs receiving air compared to sham animals increased 12-fold for IL-1ß, 121-fold for IL-6, and 17-fold for IL-8 (all p<0.001). Conclusion: Venous air embolism in pigs activated C3 without a corresponding C5 activation and triggered thromboinflammation, consistent with a C3-dependent mechanism. C3-inhibition might represent a therapeutic approach to attenuate this response.

Never-smokers and the fraction of breast cancer attributable to second-hand smoke from parents during childhood: the Norwegian Women and Cancer Study 1991-2018.

BACKGROUND: Second-hand smoke (SHS) is not an established risk factor for breast cancer. We examined exposure to SHS from parents during childhood and breast-cancer risk overall and by oestrogen- and progesterone-receptor status in the Norwegian Women and Cancer Study. Furthermore, we utilized our nationally representative prospective cohort study to estimate the fraction of breast cancer attributable to parental SHS during childhood. METHODS: We followed 45 923 never-smoking women, aged 34-70 years, who completed a baseline questionnaire between 1991 and 2007 through linkages to national registries through December 2018. We used Cox proportional-hazards models to estimate age-adjusted hazard ratios (HRs) and 95% confidence intervals (CIs). We estimated the attributable and the population attributable fraction of breast cancer with 95% CIs. RESULTS: During a mean follow-up of 19.8 (6.8) years, 2185 women developed invasive breast cancer, confirmed by histology. Women exposed to SHS from parents during childhood had an 11% higher (95% CI: 1.02-1.22) risk of breast cancer compared with those who were not. No difference was found for oestrogen (Pheterogeneity = 0.31) and progesterone (Pheterogeneity = 0.95) receptor status. For women exposed, the attributable fraction was 10.3% (95% CI: 1.8-18.0), whereas the population attributable fraction of breast cancer was 7.0% (95% CI: 1.0-13.0). CONCLUSIONS: Our results suggest that 1 in 14 breast-cancer cases could have been avoided in the absence of SHS exposure from parents during childhood in a population of never-smoking women. The cancer burden attributable to SHS may be underestimated.

Non-linear associations between healthy Nordic foods and all-cause mortality in the NOWAC study: a prospective study.

BACKGROUND: The shape of the associations between intake of foods basic in a healthy Nordic diet and long-term health is not well known. Therefore, we have examined all-cause mortality in a large, prospective cohort of women in Norway in relation to intake of: Nordic fruits and vegetables, fatty fish, lean fish, wholegrain products, and low-fat dairy products. METHODS: A total of 83 669 women who completed a food frequency questionnaire between 1996 and 2004 were followed up for mortality until the end of 2018. Cox proportional hazards regression models were used to examine the associations between consumption of the Nordic food groups and all-cause mortality. The Nordic food groups were examined as categorical exposures, and all but wholegrain products also as continuous exposures in restricted cubic spline models. RESULTS: A total of 8 507 women died during the 20-year follow-up period. Nordic fruits and vegetables, fatty fish and low-fat dairy products were observed to be non-linearly associated with all-cause mortality, while higher intake of lean fish and wholegrain products reduced all-cause mortality. Intake levels and hazard ratios (HR) and 95% confidence intervals (CI) associated with lowest mortality were approximately 200 g/day of Nordic fruits and vegetables (HR 0.83 (95% CI: 0.77-0.91)), 10-20 g/day of fatty fish (10 g/day: HR 0.98 (95% CI: 0.94-1.02)) and 200 g/day of low-fat dairy products (HR 0.96 (95% CI: 0.81-1.01)) compared to no consumption. Consumption of fatty fish ≥ 60 g/day compared to no intake statistically significantly increased the mortality (60 g/day: HR 1.08 (95% CI: 1.01-1.16)), as did consumption of low-fat dairy products ≥ 800 g/day compared to no intake (800 g/day: HR 1.10 (95% CI: 1.02-1.20)). After stratification by smoking status, the observed association between Nordic fruits and vegetables and all-cause mortality was stronger in ever smokers. CONCLUSION: The associations between intake of foods basic in healthy Nordic diets and all-cause mortality may be non-linear. Therefore, assumptions of linear associations between traditional Nordic food groups and health outcomes could lead to wrong conclusions in analyses of healthy Nordic diets.

Combined Lifestyle Behaviors and the Incidence of Common Cancer Types in the Norwegian Women and Cancer Study (NOWAC).

INTRODUCTION: Only a small number of studies have examined the impact of combined lifestyle behaviors on cancer incidence, and never in a Norwegian population. PURPOSE: To examine linear and nonlinear associations of combined lifestyle factors, assessed through a healthy lifestyle index (HLI), with the incidence of postmenopausal breast, colorectal, lung, postmenopausal endometrial, postmenopausal ovarian, pancreatic, and kidney cancer among women in Norway. METHODS: This prospective study included 96,869 women enrolled in the Norwegian Women and Cancer (NOWAC) cohort. Baseline information on lifestyle factors was collected between 1996 and 2004. The HLI was constructed from five lifestyle factors: physical activity level, body mass index, smoking, alcohol consumption, and diet. Each factor contributed 0 to 4 points to the HLI score, which ranged from 0 to 20, with higher scores representing a healthier lifestyle. Multiple imputation was used to handle missing data. Cox proportional hazard regression models were used to estimate hazard ratios (HR) and 95% confidence intervals (CI). Restricted cubic splines were used to examine nonlinearity in the associations. RESULTS: The HRs for a one-point increment on the HLI score were 0.97 (95% CI: 0.96-0.98) for postmenopausal breast cancer, 0.98 (0.96-1.00) for colorectal cancer, 0.86 (0.84-0.87) for lung cancer, 0.93 (0.91-0.95) for postmenopausal endometrial cancer, 0.99 (0.96-1.02) for postmenopausal ovarian cancer, 0.92 (0.89-0.95) for pancreatic cancer, and 0.94 (0.91-0.97) for kidney cancer. Nonlinearity was observed for the inverse associations between HLI score and the incidence of lung cancer and postmenopausal breast cancer. CONCLUSION: Based on our results, healthier lifestyle, as assessed by the HLI score, was associated with lower incidence of postmenopausal breast, colorectal, lung, postmenopausal endometrial, pancreatic, and kidney cancer among women, although the magnitude and linearity varied. Adoption of healthier lifestyle behaviors should be a public health priority to reduce the cancer burden among Norwegian women.

Symptoms and signs of colorectal cancer, with differences between proximal and distal colon cancer: a prospective cohort study of diagnostic accuracy in primary care.

BACKGROUND: In an abdominal symptom study in primary care in six European countries, 511 cases of cancer were recorded prospectively among 61,802 patients 16 years and older in Norway, Denmark, Sweden, Netherlands, Belgium and Scotland. Colorectal cancer is one of the main types of cancer associated with abdominal symptoms; hence, an in-depth subgroup analysis of the 94 colorectal cancers was carried out in order to study variation in symptom presentation among cancers in different anatomical locations. METHOD: Initial data capture was by completion of standardised forms containing closed questions about symptoms recorded during the consultation. Follow-up data were provided by the GP after diagnosis, based on medical record data made after the consultation. GPs also provided free text comments about the diagnostic procedure for individual patients. Fisher's exact test was used to analyse differences between groups. RESULTS: Almost all symptoms recorded could indicate colorectal cancer. 'Rectal bleeding' had a specificity of 99.4% and a PPV of 4.0%. Faecal occult blood in stool (FOBT) or anaemia may indicate gastrointestinal bleeding: when these symptoms and signs were combined, sensitivity reached 57.5%, with 69.2% for cancer in the distal colon. For proximal colon cancers, none of 18 patients had 'Rectal bleeding' at the initial consultation, but three of the 18 did so at a later consultation. 'Abdominal pain, lower part', 'Constipation' and 'Distended abdomen, bloating' were less specific and also less sensitive than 'Rectal bleeding', and with PPV between 0.7% and 1.9%. CONCLUSIONS: Apart from rectal bleeding, single symptoms did not reach the PPV 3% NICE threshold. However, supplementary information such as a positive FOBT or persistent symptoms may revise the PPV upwards. If a colorectal cancer is suspected by the GP despite few symptoms, the total clinical picture may still reach the NICE PPV threshold of 3% and justify a specific referral.

Open chest and pericardium facilitate transpulmonary passage of venous air emboli.

BACKGROUND: Transpulmonary passage of air emboli can lead to fatal brain- and myocardial infarctions. We studied whether pigs with open chest and pericardium had a greater transpulmonary passage of venous air emboli than pigs with closed thorax. METHODS: We allocated pigs with verified closed foramen ovale to venous air infusion with either open chest with sternotomy and opening of the pleura and pericardium (n = 8) or closed thorax (n = 16). All pigs received a five-hour intravenous infusion of ambient air, starting at 4-6 mL/kg/h and increased by 2 mL/kg/h each hour. We assessed transpulmonary air passage by transesophageal M-mode echocardiography and present the results as median with inter-quartile range (IQR). RESULTS: Transpulmonary air passage occurred in all pigs with open chest and pericardium and in nine pigs with closed thorax (56%). Compared to pigs with closed thorax, pigs with open chest and pericardium had a shorter to air passage (10 minutes (5-16) vs. 120 minutes (44-212), P < .0001), a smaller volume of infused air at the time of transpulmonary passage (12 mL (10-23) vs.170 mL (107-494), P < .0001), shorter time to death (122 minutes (48-185) vs 263 minutes (248-300, P = .0005) and a smaller volume of infused air at the time of death (264 mL (53-466) vs 727 mL (564-968), P = .001). In pigs with open chest and, infused air and time to death correlated strongly (r = 0.95, P = .001). CONCLUSION: Open chest and pericardium facilitated the transpulmonary passage of intravenously infused air in pigs.