Fall-related injury among patients with vestibular schwannoma.

Vestibular schwannoma can cause vestibular dysfunction; however, conflicting evidence exists regarding whether this affects the incidence of fall-related injuries in this patient population. This matched cross-sectional and cohort study assess the risk of fall-related injuries in patients with vestibular schwannoma. The study included patients with vestibular schwannoma treated at a tertiary referral hospital in Sweden between 1988 and 2014. Information on fall-related injuries was obtained from the National Patient Register, and matched population comparisons were randomly selected in a 1:25 ratio. Fall-related injuries occurring pre- (within 5 years before the diagnosis of vestibular schwannoma) and post-diagnostically (up to 3 years after diagnosis or intervention) were registered. The association between vestibular schwannoma and fall-related injuries was estimated using logistic regression and Cox proportional hazards analyses. We identified 1153 patients with vestibular schwannoma (569 [49%] women and 584 [51%] men), and 28815 population comparisons. Among the patients, 9% and 7% had pre- and post-diagnostic fall-related injuries, respectively, and among the comparisons, 8% and 6% had pre- and post-diagnostic fall-related injuries, respectively. There was no increased risk of pre- (OR 1.14; CI 0.92-1.41) or post-diagnostic 1 year (HR 1.16; CI 0.87-1.54) or 3 years (HR 1.11; CI 0.89-1.29) fall-related injury among the total patient cohort. In age-stratified analyses, we found an increased risk of pre-diagnostic fall-related injury among patients aged 50-69 years (OR 1.42; CI 1.10-1.88). Patients who underwent middle fossa surgery, regardless of age, had an increased risk of post-surgery fall-related injury within 3 years of follow-up (HR 2.68; CI 1.06-6.81). We conclude that patients with vestibular schwannoma have a low risk of enduring fall-related injuries. Middle-aged patients with dizziness and fall-related injuries should be considered for a vestibular clinical evaluation. Our results highlight the importance of rehabilitation in avoiding future fall-related injuries among patients undergoing middle fossa surgery.

Effects of Recall and Selection Biases on Modeling Cancer Risk From Mobile Phone Use: Results From a Case-Control Simulation Study.

BACKGROUND: The largest case-control study (Interphone study) investigating glioma risk related to mobile phone use showed a J-shaped relationship with reduced relative risks for moderate use and a 40% increased relative risk among the 10% heaviest regular mobile phone users, using a categorical risk model based on deciles of lifetime duration of use among ever regular users. METHODS: We conducted Monte Carlo simulations examining whether the reported estimates are compatible with an assumption of no effect of mobile phone use on glioma risk when the various forms of biases present in the Interphone study are accounted for. Four scenarios of sources of error in self-reported mobile phone use were considered, along with selection bias. Input parameters used for simulations were those obtained from Interphone validation studies on reporting accuracy and from using a nonresponse questionnaire. RESULTS: We found that the scenario simultaneously modeling systematic and random reporting errors produced a J-shaped relationship perfectly compatible with the observed relationship from the main Interphone study with a simulated spurious increased relative risk among heaviest users (odds ratio = 1.91) compared with never regular users. The main determinant for producing this J shape was higher reporting error variance in cases compared with controls, as observed in the validation studies. Selection bias contributed to the reduced risks as well. CONCLUSIONS: Some uncertainty remains, but the evidence from the present simulation study shifts the overall assessment to making it less likely that heavy mobile phone use is causally related to an increased glioma risk.

Mobile phone use and brain tumour risk - COSMOS, a prospective cohort study.

BACKGROUND: Each new generation of mobile phone technology has triggered discussions about potential carcinogenicity from exposure to radiofrequency electromagnetic fields (RF-EMF). Available evidence has been insufficient to conclude about long-term and heavy mobile phone use, limited by differential recall and selection bias, or crude exposure assessment. The Cohort Study on Mobile Phones and Health (COSMOS) was specifically designed to overcome these shortcomings. METHODS: We recruited participants in Denmark, Finland, the Netherlands, Sweden, and the UK 2007-2012. The baseline questionnaire assessed lifetime history of mobile phone use. Participants were followed through population-based cancer registers to identify glioma, meningioma, and acoustic neuroma cases during follow-up. Non-differential exposure misclassification was reduced by adjusting estimates of mobile phone call-time through regression calibration methods based on self-reported data and objective operator-recorded information at baseline. Hazard ratios (HR) and 95% confidence intervals (CI) for glioma, meningioma, and acoustic neuroma in relation to lifetime history of mobile phone use were estimated with Cox regression models with attained age as the underlying time-scale, adjusted for country, sex, educational level, and marital status. RESULTS: 264,574 participants accrued 1,836,479 person-years. During a median follow-up of 7.12 years, 149 glioma, 89 meningioma, and 29 incident cases of acoustic neuroma were diagnosed. The adjusted HR per 100 regression-calibrated cumulative hours of mobile phone call-time was 1.00 (95 % CI 0.98-1.02) for glioma, 1.01 (95 % CI 0.96-1.06) for meningioma, and 1.02 (95 % CI 0.99-1.06) for acoustic neuroma. For glioma, the HR for ≥ 1908 regression-calibrated cumulative hours (90th percentile cut-point) was 1.07 (95 % CI 0.62-1.86). Over 15 years of mobile phone use was not associated with an increased tumour risk; for glioma the HR was 0.97 (95 % CI 0.62-1.52). CONCLUSIONS: Our findings suggest that the cumulative amount of mobile phone use is not associated with the risk of developing glioma, meningioma, or acoustic neuroma.

Early mortality in children with cancer in Denmark and Sweden: The role of social background in a setting with universal healthcare.

Socioeconomic differences in overall survival from childhood cancer have been shown previously, but the underlying mechanisms remain unclear. We aimed to investigate if social inequalities were seen already for early mortality in settings with universal healthcare. From national registers, all children diagnosed with cancer at ages 0-19 years, during 1991-2014, in Sweden and Denmark, were identified, and information on parental social characteristics was collected. We estimated odds ratios (OR) and 95% confidence intervals (CI) of early mortality (death within 90 days after cancer diagnosis) by parental education, income, employment, cohabitation, and country of birth using logistic regression. For children with acute lymphoblastic leukaemia (ALL), clinical characteristics were obtained. Among 13,926 included children, 355 (2.5%) died within 90 days after diagnosis. Indications of higher early mortality were seen among the disadvantaged groups, with the most pronounced associations observed for maternal education (ORadj_Low_vs_High 1.65 [95% CI 1.22-2.23]) and income (ORadj_Q1(lowest)_vs_Q4(highest) 1.77 [1.25-2.49]). We found attenuated or null associations between social characteristics and later mortality (deaths occurring 1-5 years after cancer diagnosis). In children with ALL, the associations between social factors and early mortality remained unchanged when adjusting for potential mediation by clinical characteristics. In conclusion, this population-based cohort study indicated differences in early mortality after childhood cancer by social background, also in countries with universal healthcare. Social differences occurring this early in the disease course requires further investigation, also regarding the timing of diagnosis.

Suicide attempt and death by suicide among parents of young individuals with cancer: A population-based study in Denmark and Sweden.

BACKGROUND: The psychological toll on parents of a child receiving a cancer diagnosis is known to be high, but there is a knowledge gap regarding suicidal behavior among these parents. The aim of this study was to investigate the risk of suicide attempt and death by suicide in relation to having a child with cancer. METHODS AND FINDINGS: We performed a binational population-based and sibling-controlled cohort study, including all parents with a child diagnosed with cancer in Denmark (1978 to 2016) or Sweden (1973 to 2014), 10 matched unexposed parents per exposed parent (population comparison), and unaffected full siblings of the exposed parents (sibling comparison). Suicide attempt was identified through the Patient Register and the Psychiatric Central Register in Denmark and the Patient Register in Sweden, whereas death by suicide was identified through the Danish Causes of Death Register and the Swedish Causes of Death Register. In population comparison, we used Cox regression to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) of suicide attempt and death by suicide associated with cancer diagnosis of a child, adjusting for sex, age, country of residence, calendar year, marital status, highest attained educational level, household income, history of cancer, history of psychiatric disorder, and family history of psychiatric disorder. The sibling comparison was performed to assess the role of familial confounding in the studied associations. The population comparison consisted of 106,005 exposed parents and 1,060,050 matched unexposed parents, with a median age of 56 at cohort entry and 46.9% male. During the median follow-up of 7.3 and 7.2 years, we observed 613 (incidence rate [IR], 58.8 per 100,000 person-years) and 5,888 (IR, 57.1 per 100,000 person-years) cases of first-onset suicide attempt among the exposed and unexposed parents, respectively. There was an increased risk of parental suicide attempt during the first years after a child's cancer diagnosis (HR, 1.15; 95% CI, [1.03, 1.28]; p = 0.01), particularly when the child was 18 or younger at diagnosis (HR, 1.25; 95% CI, [1.08, 1.46]; p = 0.004), when the child was diagnosed with a highly aggressive cancer (HR, 1.60; 95% CI, [1.05, 2.43]; p = 0.03), or when the child died due to cancer (HR, 1.63; 95% CI, [1.29, 2.06]; p < 0.001). The increased risk did not, however, maintain thereafter (HR, 0.86; 95% CI: [0.75, 0.98]; p = 0.03), and there was no altered risk of parental death by suicide any time after the child's cancer diagnosis. Sibling comparison corroborated these findings. The main limitation of the study is the potential residual confounding by factors not shared between full siblings. CONCLUSIONS: In this study, we observed an increased risk of parental suicide attempt during the first years after a child's cancer diagnosis, especially when the child was diagnosed during childhood, or with an aggressive or fatal form of cancer. There was, however, no altered risk of parental death by suicide at any time after a child's cancer diagnosis. Our findings suggest extended clinical awareness of suicide attempt among parents of children with cancer, especially during the first few years after cancer diagnosis.

Educational attainment in survivors of childhood cancer in Denmark, Finland, and Sweden.

BACKGROUND: Survivors of childhood cancer may face difficulties at school. We investigated whether childhood cancer affects attainment of upper secondary education, in a register-based cohort study from Denmark, Finland, and Sweden, where we limit bias from selection and participation. METHODS: From the national cancer registers, we identified all long-term survivors of childhood cancer diagnosed aged 0-14 years in 1971-2005 (n = 7629), compared them to matched population comparisons (n = 35,411) and siblings (n = 6114), using odds ratios (OR) and 95% confidence intervals (CI). RESULTS: Overall, 6127 survivors (80%) had attained upper secondary education by age 25, compared to 84% among comparison groups. Elevated OR for not attaining this level were mainly confined to survivors of central nervous system (CNS) tumours (ORSurv_PopComp2.05, 95%CI: 1.83-2.29). Other risk groups were survivors who had spent more time in hospital around cancer diagnosis and those who had hospital contacts in early adulthood, particularly psychiatric. Survivors of all cancer types were less likely to have attained upper secondary education without delay. CONCLUSIONS: Although survivors of childhood cancer experienced delays in their education, many had caught up by age 25. Except for survivors of CNS tumours, survivors attained upper secondary education to almost the same extent as their peers.

Risk of head and neck cancer in relation to blood inflammatory biomarkers in the Swedish AMORIS cohort.

Background: Inflammation is critically involved in the development of human cancer, and blood inflammatory biomarkers have been proposed to indicate the risk of different cancer types. Methods: Using the Swedish Apolipoprotein-Related Mortality Risk (AMORIS) Cohort (N=812,073), we first performed a time-to-event analysis to evaluate the association of the baseline level of 12 blood inflammatory biomarkers measured during 1985-1996 with the subsequent risk of head and neck cancer (HNC) identified through the nationwide Swedish Cancer Register until end of 2020. A nested case-control study was further conducted to demonstrate the longitudinal trends of the studied biomarkers during the 30-year period prior to diagnosis of HNC. Results: In the time-to-event analysis, we identified a total of 2,510 newly diagnosed HNC cases. There was an increased risk of HNC per standard deviation (SD) increase of haptoglobin (hazard ratio [HR]: 1.25; 95% confidence interval [CI]: 1.21-1.30), leukocytes (HR: 1.22; 95%CI: 1.17-1.28), sedimentation rate (HR: 1.17; 95%CI: 1.07-1.29), and monocytes (HR: 1.34; 95%CI: 1.07-1.68) at baseline, after adjustment for age, sex, fasting status, occupational status, and country of birth. In contrast, there was a decreased risk of HNC per SD increase of lymphocytes in % (HR: 0.85; 95%CI: 0.73-0.99) and lymphocyte-to-monocyte ratio (LMR) (HR: 0.81; 95%CI: 0.69-0.95) at baseline. In the nested case-control study using repeatedly measured biomarker levels, we found that individuals with HNC had consistently higher levels of haptoglobin, leukocytes, sedimentation rate, and monocytes, as well as consistently lower levels of lymphocytes in % and LMR, during the 30-year period prior to diagnosis, compared to controls. Conclusion: Based on a cohort of more than half a million participants with up to 35 years of follow-up, our findings provide solid evidence supporting the presence of alterations in blood inflammatory biomarkers during the decades before diagnosis of HNC.

Parental occupational exposure to metals and risk of cancer in the offspring: A register-based case-control study from Sweden.

BACKGROUND: Cancer risks in the offspring of mothers and fathers exposed to metals are unknown. We estimated the relative risks of childhood cancer, overall and by type, associated with parental occupational exposure to arsenic, cadmium, chromium, nickel, and lead. METHODS: We conducted a nested case-control study (1960-2015) of children born in Sweden aged 0-19 years diagnosed with cancer (National Cancer Register) matched 25:1 to controls on birth year and sex. We obtained parental occupational data around their birth from censuses and a nationwide register and identified exposure to each metal (yes/no, or higher/lower/no exposure) using the Swedish job-exposure matrix (SWEJEM). Adjusted odds ratios (OR) and 95% confidence intervals (CIs) were estimated separately for maternal and paternal exposures using conditional logistic regression. RESULTS: We compared 9653 cases to 1,72,194 controls in maternal and 12,521 cases to 2,74,434 controls in paternal analyses, respectively. We found a 38% increased risk of cancer associated with maternal occupational exposure to arsenic (OR 1.38 [95% CI 1.06, 1.82]), likely driven by higher risks for lymphoma (OR 1.52 [0.73, 3.15]), central nervous system (CNS) (OR 1.49 [0.88, 2.54]) and other solid malignancies (OR 1.74 [1.14, 2.65]). There were also indications of higher risks of lymphoma in children of mothers exposed to nickel and iron, and of CNS tumours due to chromium exposure. No associations were observed from paternal occupational exposure to any of the metals. CONCLUSIONS: We found evidence of increased risks of cancer in children of mothers but not fathers occupationally exposed to arsenic and potentially other metals.

Neurocutaneous Syndromes, Perinatal Factors, and the Risk of Childhood Cancer in Sweden.

Importance: Neurocutaneous syndromes are associated with cancer predisposition and sometimes associated with perinatal factors. A better understanding of the association between neurocutaneous syndromes, perinatal factors, and childhood cancer is key for earlier cancer detection. Objective: To evaluate the association of neurocutaneous syndromes and perinatal factors with childhood cancer risk in a cohort of Swedish children. Design, Setting, and Participants: In this nationwide cohort study, all children and adolescents up to age 20 years, from 1973 to 2015, were identified through the Swedish National Medical Birth Register (MBR), provided they had information on both biological parents. Analyses were conducted from April 2021 through May 2023. Exposures: Diagnoses of neurocutaneous syndromes were obtained from the MBR, National Patient Register, and Cause of Death register. Perinatal factors (birth weight, gestational age, birth weight by gestational age, 5-minute Apgar score, and head circumference) were obtained from the MBR. Main Outcomes and Measures: Childhood cancer risk (<20 years at diagnosis; identified from the National Cancer Register), including leukemia, lymphoma, and central nervous system (CNS) tumors. Results: Among 4 173 108 included children (2 143 133 [51.4%] male, median [IQR] follow-up 20 [9.7-20] years), 1783 had neurofibromatosis type 1 (NF1), 444 tuberous sclerosis, 63 von Hippel-Lindau disease, and 39 ataxia-telangiectasia. An increased cancer risk was observed among children with any neurocutaneous syndrome (HR, 34.9; 95% CI, 30.8-39.6) and was particularly pronounced for CNS tumors (HR, 111.7; 95% CI, 96.8-128.8), except among children with ataxia-telangiectasia, where the increased risk was associated with lymphomas (HR, 233.1; 95% CI, 75.0-724.1). Leukemia risk was increased only among children with NF1 (HR, 4.1; 95% CI, 1.7-9.8). Several perinatal factors, including high birth weight, being born large for gestational age, preterm birth, low 5-minute Apgar score, and large head circumference had lesser associations with childhood cancer. Adjusting for neurocutaneous syndromes did not affect these associations. Conclusions and Relevance: In this nationwide cohort study, neurocutaneous syndromes were associated with an increased risk of childhood cancer, especially CNS tumors. Several perinatal factors had lesser associations with childhood cancer, independently of the presence of neurocutaneous syndromes. Other biological mechanisms likely underlie the association between perinatal factors and childhood cancer.

Income disparities between adult childhood cancer survivors and their peers-A register-based cohort study from the SALiCCS research programme.

BACKGROUND: Childhood cancer survivors face various adverse consequences. This Nordic register-based cohort study aimed to assess whether survivors of childhood cancer are more likely to have low income than their peers. METHODS: We identified 17,392 childhood cancer survivors diagnosed at ages 0 to 19 between 1971 and 2009 with 83,221 age-, sex-, and country-matched population comparisons. Annual disposable income at ages 20 to 50 years was retrieved from statistical offices (for 1990-2017) and categorized into low income and middle/high income. The number of transitions between income categories were assessed using binomial regression analyses. RESULTS: The prevalence of annual low income among childhood cancer survivors was 18.1% and 15.6% among population comparisons (risk ratio [RR] 1.17; 95% confidence interval [CI] 1.16-1.18). Compared to population comparisons, childhood cancer survivors were 10% (95% CI 8%-11%) less likely to transition from low to middle/high income and 12% (10%-15%) more likely to transition from middle/high to low income during follow-up. Among those initially in the low income category, survivors were 7% (95% CI 3%-11%) more likely to remain in the low income category. If the initial category was middle/high income, childhood cancer survivors were 10% (95% CI 8%-11%) less likely to remain in the middle/high income and 45% (37%-53%) more likely to transition to the low income category permanently. CONCLUSIONS: Childhood cancer survivors are at higher risk for low income in adulthood than their peers. These disparities might be reduced by continued career counseling along with support in managing within the social security system.

Risk of All-Cause Dementia, Alzheimer Disease, and Vascular Dementia in Breast Cancer Survivors: A Longitudinal Register-Based Study.

Background and Objectives: Now more than two-thirds of cancer survivors are aged 65 years or older, but evidence about their long-term health is thin. Cancer and its treatments have been linked to accelerated aging, so there is a concern that aging cancer survivors have an increased risk of age-related diseases, including dementia. Methods: We examined the risk of dementia among 5-year breast cancer survivors using a matched cohort study design. We included breast cancer survivors aged 50 years and older at diagnosis (n = 26,741) and cancer-free comparison participants (n = 249,540). Women eligible for inclusion in the study were those born 1935-1975 and registered in the Swedish Total Population Register between January 1, 1991, and December 31, 2015. We defined breast cancer survivors as women with an initial breast cancer diagnosis between 1991 and 2005 who survived 5 or more years after their first diagnosis. We assessed all-cause dementia, Alzheimer disease (AD), and vascular dementia (VaD) using International Classification of Diseases codes. Survival analyses were conducted using age-adjusted subdistribution hazard models accounting for competing risk of death. Results: We did not observe an association between breast cancer survivorship and risk of all-cause dementia, AD, or VaD. However, in models stratified by age at cancer diagnosis, women diagnosed with cancer after age 65 years had a higher risk of all-cause dementia (subdistribution hazard ratio [SHR] = 1.30, 95% CI 1.07-1.58), AD (SHR = 1.35, 95% CI 1.05-1.75), and VaD (SHR = 1.64, 95% CI 1.11-2.43) in models adjusted for age, education, and country of origin. Discussion: Older breast cancer survivors who survive cancer have a higher risk for dementia than their peers without a cancer diagnosis, in contrast to earlier studies showing that prevalent or incident cancer is associated with a lower risk of dementia. With the older adult population growing rapidly and because cancer and dementia are 2 of the most common and debilitating diseases among older adults, it is critical that we understand the link between the 2.

Frailty Among Breast Cancer Survivors: Evidence From Swedish Population Data.

Incidence and survival of breast cancer, the most common cancer among women, have been increasing, leaving survivors at risk of aging-related health conditions. In this matched cohort study, we examined frailty risk with the Hospital Frailty Risk Score among breast cancer survivors (n = 34,900) and age-matched comparison subjects (n = 290,063). Women born in 1935-1975, registered in the Swedish Total Population Register (1991-2015), were eligible for inclusion. Survivors had a first breast cancer diagnosis in 1991-2005 and survived ≥5 years after initial diagnosis. Death date was determined by linkage to the National Cause of Death Registry (through 2015). Cancer survivorship was weakly associated with frailty (subdistribution hazard ratio (SHR) = 1.04, 95% confidence interval (CI): 1.00, 1.07). In age-stratified models, those diagnosed at younger ages (<50 years) had higher risk of frailty (SHR = 1.12, 95% CI: 1.00, 1.24) than those diagnosed at ages 50-65 (SHR = 1.03, 95% CI: 0.98, 1.07) or >65 (SHR = 1.09, 95% CI: 1.02, 1.17) years. Additionally, there was increased risk of frailty for diagnoses in 2000 or later (SHR = 1.15, 95% CI: 1.09, 1.21) compared with before 2000 (SHR = 0.97, 95% CI: 0.93, 1.17). This supports work from smaller samples showing that breast cancer survivors have increased frailty risk, particularly when diagnosed at younger ages.

The Risk of Cholesteatoma in Individuals With First-degree Relatives Surgically Treated for the Disease.

Importance: Cholesteatoma in the middle ear is not regarded as a hereditary disease, but case reports of familial clustering exist in the literature, as well as observed familial cases in the clinical work. However, the knowledge regarding cholesteatoma as a hereditary disease is lacking in the literature. Objective: To assess the risk of cholesteatoma in individuals with a first-degree relative surgically treated for the same disease. Design, Setting, and Participants: In this nested case-control study in the Swedish population between 1987 and 2018 of first-time cholesteatoma surgery identified from the Swedish National Patient Register, 2 controls per case were randomly selected from the population register through incidence density sampling, and all first-degree relatives for cases and controls were identified. Data were received in April 2022, and analyses were conducted between April and September 2022. Exposure: Cholesteatoma surgery in a first-degree relative. Main Outcomes and Measures: The main outcome was first-time cholesteatoma surgery. The association between having a first-degree relative with cholesteatoma and the risk of cholesteatoma surgery in the index persons was estimated by odds ratios (ORs) and 95% CIs through conditional logistic regression analysis. Results: Between 1987 and 2018, 10 618 individuals with a first-time cholesteatoma surgery (mean [SD] age at surgery, 35.6 [21.5] years; 6302 [59.4%] men) were identified in the Swedish National Patient Register. The risk of having a cholesteatoma surgery was almost 4 times higher in individuals having a first-degree relative surgically treated for the disease (OR, 3.9; 95% CI, 3.1-4.8), but few cases were exposed overall. Among the 10 105 cases with at least 1 control included in the main analysis, 227 (2.2%) had at least 1 first-degree relative treated for cholesteatoma, while the corresponding numbers for controls were 118 of 19 553 control patients (0.6%). The association was stronger for individuals under the age of 20 years at first surgery (OR, 5.2; 95% CI, 3.6-7.6) and for a surgery involving the atticus and/or mastoid region (OR, 4.8; 95% CI, 3.4-6.2). There was no difference in the prevalence of having a partner with cholesteatoma between cases and controls (10 cases [0.3%] and 16 controls [0.3%]; OR, 0.92; 95% CI, 0.41-2.05), which implies that increased awareness does not explain the association. Conclusions and Relevance: In this Swedish case-control study using nationwide register data with high coverage and completeness, the findings suggest that the risk of cholesteatoma in the middle ear is strongly associated with a family history of the condition. Family history was nevertheless quite rare and can therefore only explain a limited number of all cases; these families could be an important source for information regarding the genetic background for cholesteatoma disease.

Use of Nonsteroidal Anti-Inflammatory Drugs and Risk of Breast Cancer: Evidence from a General Female Population and a Mammographic Screening Cohort in Sweden.

A link has been proposed between the use of nonsteroidal anti-inflammatory drugs (NSAIDs) and the risk of breast cancer. There is, however, insufficient data regarding the subtype and stage of breast cancer, and few studies have assessed the interaction between the use of NSAIDs and breast density or previous breast disorders. There is also a lack of data from population-based studies. We first conducted a nested case-control study within the general female population of Sweden, including 56,480 women with newly diagnosed breast cancer during 2006-2015 and five breast cancer-free women per case as controls, to assess the association of NSAID use with the risk of incident breast cancer, focusing on subtype and stage of breast cancer as well as the interaction between NSAID use and previous breast disorders. We then used the Karolinska Mammography Project for Risk Prediction of Breast Cancer (Karma) cohort to assess the interaction between NSAID use and breast density in relation to the risk of breast cancer. Conditional logistic regression was used to estimate the hazard ratio (HR) and a 95% confidence interval (CI) was used for breast cancer in relation to the use of aspirin and non-aspirin NSAIDs. In the nested case-control study of the general population, exclusive use of aspirin was not associated with the risk of breast cancer, whereas exclusive use of non-aspirin NSAIDs was associated with a modestly higher risk of stage 0-2 breast cancer (HR: 1.05; 95% CI: 1.02-1.08) but a lower risk of stage 3-4 breast cancer (HR 0.80; 95% CI: 0.73-0.88). There was also a statistically significant interaction between the exclusive use of NSAIDs and previous breast disorders (p for interaction: <0.001). In the analysis of Karma participants, the exclusive use of non-aspirin NSAIDs was associated with a lower risk of breast cancer among women with a breast dense area of >40 cm2 (HR: 0.72; 95% CI: 0.59-0.89). However, the possibility of finding this by chance cannot be ruled out. Overall, we did not find strong evidence to support an association between the use of NSAIDs and the risk of breast cancer.

Blood metabolic biomarkers and the risk of head and neck cancer: An epidemiological study in the Swedish AMORIS Cohort.

Multiple studies have investigated the role of carbohydrate and lipid metabolism on the risk of head and neck cancer (HNC), with however conflicting results. We performed a study of 561,388 individuals of the Swedish AMORIS Cohort with blood test results on nine biomarkers for carbohydrate, lipid, and apolipoprotein metabolism during 1985-1996. We examined the associations of these biomarkers with the future risk of HNC through 2020 and demonstrated the temporal changes of these biomarkers during the decades before cancer diagnosis. We found that there was a positive association between blood level of glucose, total cholesterol (TC), triglycerides (TG), and Apoprotein A-I (ApoA-I) and the risk of HNC. Per standard deviation increase, the hazard ratio (HR) was 1.05 (95% confidence interval [CI] 1.02-1.09) for glucose, 1.09 (95% CI 1.05-1.13) for TC, 1.13 (95% CI 1.08-1.17) for TG, and 1.11 (95% CI 1.04-1.19) for ApoA-I. The associations were primarily noted for squamous cell carcinoma but not adenocarcinoma. Compared to controls, patients with HNC, primarily squamous cell carcinoma, showed constantly higher levels of glucose, TC, TG, and ApoA-I during the 30 years before diagnosis. In conclusion, findings of the study add new and high-quality evidence to the early involvement of carbohydrate and lipid metabolism in the oncogenesis of human cancer.

Carbohydrate, Lipid, and Apolipoprotein Biomarkers in Blood and Risk of Thyroid Cancer: Findings from the AMORIS Cohort.

Background: Previous studies have examined the link between blood metabolic biomarkers and risk of thyroid cancer, with inconclusive results. We performed a cohort study based on the Swedish Apolipoprotein-Related Mortality Risk (AMORIS) Cohort, including 561,388 individuals undergoing health examinations during 1985−1996 with a follow-up of >30 years. Methods: Newly diagnosed cases of thyroid cancer were identified from the Swedish Cancer Register. We assessed the associations of nine blood biomarkers of carbohydrate, lipid, and apolipoprotein metabolism measured at the time of health examinations with the subsequent risk of thyroid cancer and demonstrated the temporal trend of these biomarkers during the 30 years before diagnosis of thyroid cancer. Results: After multivariable adjustment, there was a lower risk of thyroid cancer, per standard deviation increase in total cholesterol (TC; HR 0.91; 95%CI 0.82−0.99) and HDL-C (HR 0.86; 95%CI 0.75−0.99). During the 20 to 30 years before diagnosis, patients with thyroid cancer, as a group, demonstrated constantly lower levels of TC and HDL-C, compared to controls. Further, patients with thyroid cancer demonstrated declining levels of these biomarkers during the ten years before diagnosis, whereas controls demonstrated stable or increasing levels. Conclusions: Taken together, we found blood levels of TC and HDL-C to be associated with the risk of thyroid cancer and that there was a declining level of metabolic biomarkers during the 10 years before diagnosis of thyroid cancer.

Heritability of nervous system tumors: a sibling-based design.

Background: The contribution of genetic and environmental factors to susceptibility to nervous system tumors remains unclear. We performed a quantitative genetic study using a sibling design to estimate the heritability of nervous system tumors, as well as the proportion of the risk of these tumors, which is attributable to environmental factors. Methods: We conducted a population-based cohort study using Swedish National Register data. All individuals born in Sweden during 1950-2010 with available information on both biological parents were included. A Multi-Generation Register was used to identify family clusters, including both full- and half-siblings. Initially, one index person was randomly selected from each cluster containing only full siblings and one sibling was randomly assigned to this index person. Subsequently, within each of the remaining clusters of full- and half-siblings, an index person was randomly selected, and a half-sibling was randomly assigned to this index person. Among the randomly selected siblings, cases of nervous system tumors were identified using the cancer registry. Quantitative genetic models were used to estimate the proportion of the variance in nervous system tumors attributable to additive genetic factors, shared environment, and individual-specific environment. Results: The heritability of nervous system tumors was estimated to be 29% (95% confidence interval (CI) = 19%-39%), while the contribution of the non-shared environment to the variance of nervous system tumors was estimated to be 71% (95% CI = 61%-81%). The shared environmental parameter was estimated as zero in the full model. Conclusion: The variation in susceptibility to nervous system tumors is predominantly attributable to non-shared environmental factors, followed by genetic factors.