Nathalie C Støer

Cancer Registry of Norway · Department of Research

Background It is important to monitor the association between menopausal hormone therapy (HT) use and breast cancer (BC) risk with contemporary estimates, and specifically focus on HT types and new drugs. Methods We estimated hazard ratios (HR) of BC risk according to HT type, administration route and individual drugs, overall and stratified by bo...

Objectives We aimed to describe the trajectories of cognitive and physical symptoms before, during, and after a positive- or negative SARS-CoV-2 test and in untested controls. Design A prospective cohort study. Setting Norway, 27 March 2020 to 6 July 2022 Participants A total of 146 065 volunteers were recruited. Of these, 120 605 participants (mea...

Aspirin and non-aspirin non-steroidal anti-inflammatory (NSAID) drugs have been associated with survival in women with a history of epithelial ovarian cancer (EOC). Studies to date are generally limited to self-reported exposure data and with limited data by disease histotype. We conducted a registry-based cohort study including EOC incidence and d...

Objectives To examine the association between low-dose aspirin use and risk of colorectal cancer (CRC). Methods In this nationwide cohort study, we identified individuals aged ≥50 years residing for 6 months or more in Norway in 2004-2018, and obtained data from national registers on drug prescriptions, cancer occurrence, and sociodemographic fact...

Introduction/Background Endometrial cancer (EC) is the most common gynaecological cancer in Norway, with rising incidence. There is a strong need for primary and secondary prevention strategies. While non-steroidal anti-inflammatory drugs (NSAIDs) have been shown to improve survival in other cancers, data in patients with EC is conflicting. Method...

Background Previous studies assessed the prognostic effect of aspirin, statins, and metformin in breast cancer (BC) patients, with inconclusive results. Methods We performed a nationwide population-based cohort study to evaluate if post-diagnostic use of low-dose aspirin, statins, and metformin was associated with BC-specific survival. Women aged...

Objectives: Epidemiological studies have reported an association between antimuscarinics and reduced risk of cancer, including lung cancer (LC). However, the potential association between antimuscarinic use and LC prognosis has not previously been assessed. In a large population-based cohort, we aimed to investigate the association between the use...

Human papillomavirus (HPV) vaccine effectiveness may differ between settings. Here we present the first real‐world effectiveness study of HPV vaccination on high‐grade cervical lesions from Norway, among women who received HPV vaccine outside the routine program. We performed an observational study of all Norwegian women born 1975 to 1996 and retri...

Several studies evaluated the association between aspirin use and risk of breast cancer (BC), with inconsistent results. We identified women aged ≥ 50 years residing in Norway between 2004 and 2018, and linked data from nationwide registries; including the Cancer Registry of Norway, the Norwegian Prescription Database, and national health surveys....

Background: The possible protective effect of aspirin on risk of colorectal cancer (CRC) is still highly debated. Methods: We used data from Bowel Cancer Screening in Norway, a trial randomizing individuals from general population, aged 50-74 years, to flexible sigmoidoscopy or faecal immunochemical test (FIT), to study the association between a...

Background Night shift work may acutely disrupt the circadian rhythm, with possible carcinogenic effects. Prostate cancer has few established risk factors though night shift work, a probable human carcinogen, may increase the risk. We aimed to study the association between night shift work and chlorinated degreasing agents (CDAs) as possible endocr...

Background Neoadjuvant chemotherapy (NAC) before radical cystectomy is associated with pathological downstaging (DS) and improved overall survival (OS) in patients with muscle-invasive bladder cancer (MIBC). Population-based studies have not unequivocally shown improved survival. The aim of this population-based study was to evaluate the effect of...

Leon A.M. Berge, Tom K. Grimsrud, Ronnie Babigumira, Nathalie C. Støer, Nita K. Shala, Marit B. Veierød and Jo S. Stenehjem: Cancer epidemiology in practice: Working notes on cancer history-based selection and censoring

Background The association between use of β-blockers and breast cancer (BC) prognosis has been investigated in several observational studies, with conflicting results. We performed a nationwide cohort study and a meta-analysis to investigate the association, and assess if it varied between molecular subtypes of BC. Methods We identified women aged...

New evidence on the association between use of menopausal hormone therapy and increased risk of cutaneous melanoma (CM) is emerging. In the Australian Longitudinal Study on Women's Health, we followed 18,850 postmenopausal women for a median of 13.2 years, and observed 356 incident CMs. We found an indication of an association between use of unoppo...

BACKGROUND The availability of mobile phones has made the dissemination of health-related information easy and accessible. With gamification, mobile apps can nudge people to make informed health choices, including attending cervical cancer screening. OBJECTIVE This matched retrospective cohort study examined the association between exposure to the...

Background The wide availability of mobile phones has made it easy to disseminate health-related information and make it accessible. With gamification, mobile apps can nudge people to make informed health choices, including attending cervical cancer screening. Objective This matched retrospective cohort study examined the association between exposu...

Background The prognosis of pancreatic cancer is poor and new treatment strategies are urgently needed. To identify non-cancer drugs that could be re-purposed for cancer, we investigated the association between the use of selected drugs and cancer-specific mortality in a nationwide cohort of pancreatic cancer patients. Material and methods The stu...

Funding sources: none. Conflicts of interest: the authors declare they have no conflicts of interest. Data availability: The data that support the findings of this study are available upon reasonable request from the Norwegian Women and Cancer study (https://uit.no/research/nowac). The data are not publicly available owing to privacy or ethical res...

This cohort study examines self-reported memory problems 8 months after COVID-19 infection.

Purpose Assessing the clinical importance of an exposure effect on a quality of life (QoL) score often requires quantifying the effect in terms of a difference in scores. Using the linear regression model (LRM) for this purpose assumes the ordinal score is a proxy for an underlying continuous variable, but the analysis offers no assessment for the...

We assessed associations between metformin use and survival in a nationwide Norwegian cohort of lung cancer (LC) patients. The study linked 22,324 LC patients from the Cancer Registry of Norway diagnosed 2005–2014 with the Norwegian Prescription Database. We estimated associations of pre- and post-diagnostic metformin use with overall survival (OS)...

Previous studies of serum 25-hydroxyvitamin D (25(OH)D) in relation to melanoma have shown conflicting results. We conducted a nested case–control study of 708 cases and 708 controls, using prediagnostically collected serum, to study 25(OH)D and melanoma risk in the population-based Janus Serum Bank Cohort. Stratified Cox regression was used to est...

Background: Population-based pharmaco-epidemiologic studies are used to assess postmarketing drug safety and discover beneficial effects of off-label drug use. We conducted a drug-wide association study (DWAS) to screen for associations between prescription drugs and cancer risk. Methods: This registry-based, nested case-control study, 1:10 matc...

Background: The change in two measurements of a continuous outcome can be modelled directly with a linear regression model, or indirectly with a random effects model (REM) of the individual measurements. These methods are susceptible to model misspecifications, which are commonly addressed by applying monotonic transformations (e.g., Box-Cox trans...

Background: The association between use of menopausal hormone therapy and risk of cutaneous melanoma is highly debated. We investigated the issue in a Finnish nationwide cohort of women ages 50 years or older.Methods: All women who had purchased hormone therapy between 1994 and 2007 were identified from the national Medical Reimbursement Registry...

黑色素瘤是最严重的皮肤癌,2012年,在世界范围内其导致232,000例新发癌症病例及55,000例死亡。黑色素瘤最重要的风险因素是日光紫外线辐射、室内日光浴、皮肤白皙、有许多痣(色素痣)和雀斑、浅色头发及皮肤日晒反应。女性性激素(如雌激素和孕激素)也表明对黑色素瘤的出现有作用,这是因为黑色素瘤在女性中绝经期前较男性更常见,然而在绝经期后恰恰相反。研究激素与出现黑色素瘤的风险的相关性的一种方法是研究与女性生育史相关的因素,即所谓的生育因素,例如,初潮年龄(第一次月经来潮)、月经周期、绝经年龄及从初潮到绝经的时间、子女人数、首次和末次生育年龄及哺乳总时长。在挪威女性与癌症(NOWAC)研究中,作者研究了生育因素与黑色素瘤风险的总体、身体局部和黑色素瘤亚型方面的相关性。NOWAC成立于1991年...

Melanoma is the most severe form of skin cancer and in 2012 it accounted for 232,000 new cancer cases and 55,000 deaths worldwide. The most important risk factors for melanoma are exposure to ultraviolet radiation from the sun, indoor tanning, fair skin complexion, the presence of many nevi (moles) and freckles, light hair and skin reaction to sun....

Background: Although criticisms regarding the dichotomisation of continuous variables are well known, applying logit model to dichotomised outcomes is the convention because the odds ratios are easily obtained and they approximate the relative risks (RRs) for rare events. Methods: To avoid dichotomisation when estimating RR, the marginal standar...

Background: Romania has had one of the highest rates of cervical cancer incidence and mortality in Europe for decades. Data on the high-risk human papillomavirus (hrHPV) prevalence within the Romanian population are crucial for cervical cancer intervention in high risk groups. The aim of this study was to determine the prevalence of hrHPV infectio...

Is Leisure-time Physical Activity before Pregnancy associated with risk of hyperemesis gravidarum during pregnancy? OWE KATRINE M1,2, STØER NATHALIE1,2,3, WOLD BORGNY H4, MAGNUS MARIA C.2,5,6, NYSTAD WENCHE2, VIKANES ÅSE V.7 1 Norwegian National Advisory Unit on Women’s Health, Oslo University Hospital, Oslo, Norway. 2 Norwegian Institute of Pub...

Introduction: Women who experience severe nausea and vomiting in early pregnancy are less likely to participate in leisure-time physical activity (LTPA) during pregnancy. Whether LTPA before pregnancy is associated with hyperemesis gravidarum (HG) has not yet been studied. The aim of the study was to estimate associations between prepregnancy LTPA...

The rank-ordered logit (rologit) model was recently introduced as a robust approach for analysing continuous outcomes, with the linear exposure effect estimated by scaling the rank-based log-odds estimate. Here we extend the application of the rologit model to continuous outcomes with ties and ordinal outcomes treated as imperfectly-observed contin...

Introduction Surveillance of unintended effects of pharmaceuticals (pharmacovigilance or drug safety) is crucial, as knowledge of rare or late side effects is limited at the time of the introduction of new medications into the market. Side effects of drugs may involve increased or decreased risk of cancer, but these typically appear after a long in...

Background The association between reproductive factors and risk of cutaneous melanoma (CM) is unclear. We investigated this issue in the Norwegian Women and Cancer (NOWAC) cohort study. Objectives To examine the association between the reproductive factors age at menarche, menstrual cycle length, parity, age at first and last birth, menopausal st...

From 2015, Norway has implemented high‐risk human papilloma virus (hrHPV) testing in primary screening for cervical cancer. Women aged 34–69 years, living in four counties, have been pseudo‐randomly assigned (1:1 randomization) to either hrHPV testing every 5 years (followed by cytology if hrHPV is positive), or cytology testing every 3 years (foll...

Background To quantify temporal trends in age-standardized rates of disease, the convention is to fit a linear regression model to log-transformed rates because the slope term provides the estimated annual percentage change. However, such log-transformation is not always appropriate. Methods We propose an alternative method using the rank-ordered...

黑色素瘤是挪威增长最快的癌症;2016年,2114名男性和女性被诊断为患该疾病。这种癌症通常能够在早期确诊,如果您密切关注皮肤的变化,将能够在早期检测出癌症。但是,转移性黑色素瘤(扩散到身体的其他部位)是一种难以治愈的严重疾病,挪威每年有超过300人死于黑色素瘤。肿瘤厚度(称为Breslow厚度)是患上黑色素瘤后能否存活的重要因素;诊断时肿瘤较薄的患者会比肿瘤较厚的患者生存时间更长。在挪威的一项新研究中,研究人员探索了某些因素(称为人体测量因素‐比如身体质量指数(BMI)、人体皮肤表面积(BSA)、身高、体重和体重变化)与Breslow厚度的整体关联,并按照解剖部位及组织学亚型(黑色素瘤类型)进行了分析。入选研究组(被称为基于Janus人口的1972–2003年群体)的近30万挪威男性和女性...

Melanoma is the most rapidly increasing cancer form in Norway, and in 2016, 2114 men and women were diagnosed with the disease. This form of cancer is often diagnosed at an early stage, and if you follow changes in your skin you will be able to detect the cancer at an early stage. Melanoma with metastasis (spreading elsewhere in the body), however,...

For time-to-event data, the study sample is commonly selected using the nested case–control design in which controls are selected at the event time of each case. An alternative sampling strategy is to sample all controls at the same (pre-specified) time, which can either be at the last event time or further out in time. Such controls are the long-t...

Background Breslow thickness is the most important prognostic factor of localized cutaneous melanoma (CM), but associations with anthropometric factors have been sparsely and incompletely investigated. Objectives To examine pre‐diagnostic body mass index (BMI), body surface area (BSA), height, weight and weight change in relation to Breslow thickn...

Background: It is not uncommon for investigators to conduct further analyses of subgroups, using data collected in a nested case-control design. Since the sampling of the participants is related to the outcome of interest, the data at hand are not a representative sample of the population, and subgroup analyses need to be carefully considered for...

The control of confounding is an area of extensive epidemiological research, especially in the field of causal inference for observational studies. Matched cohort and case-control study designs are commonly implemented to control for confounding effects without specifying the functional form of the relationship between the outcome and confounders....

Objectives With the present study, we aimed to investigate the association between menopausal hormone therapy (HT) and risk of colorectal cancer (CRC). Setting Cohort study based on the linkage of Norwegian population-based registries. Participants We selected 466822 Norwegian women, aged 55–79, alive and residing in Norway as of 1 January 2004,...

The association between use of menopausal hormone therapy (HT) and occurrence of skin malignant melanoma (SMM) is controversial. We investigated the issue in a nationwide cohort of 684,696 Norwegian women, aged 45-79 years, followed from 2004-2008. The study was based on linkage between Norwegian population registries. Multivariable Poisson regress...

To investigate in detail the effect of infection or vaccination on the human immune system, ELISpot assays are used to simultaneously test the immune response to a large number of peptides of interest. Scientists commonly use “peptide pools”, where, instead of an individual peptide, a test well contains a group of peptides. Since the response from...

Objective: A number of observational studies have shown an inverse association between circulating 25-hydroxyvitamin D and total mortality, but a reverse J-shaped association has also been reported. In a large nested case-control study, serum-25-hydroxyvitamin D (s-25(OH)D) was positively associated with incident prostate cancer. Based on the same...

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Reuse of controls from nested case-control designs can increase efficiency in many situations, for instance with competing risks or in other multiple endpoints situations. The matching between cases and controls must be broken when controls are to be used for other endpoints. A weighted analysis can then be performed to take care of the biased samp...

Hyperemesis gravidarum is a serious condition affecting 0.8-2.3 % of pregnant women and can be regarded as a restricted period of famine. Research concerning potential long-term consequences of the condition for the offspring, is limited, but lack of nutrition in-utero has been associated with chronic disease in adulthood, including some cancers. T...

Reproductive factors have been shown to influence cancer risk. Several pathological conditions during pregnancy have also been associated with subsequent increased cancer risk in the mother. Hyperemesis gravidarum (hyperemesis) is an early pregnancy condition characterized by severe nausea and vomiting resulting in weight loss and metabolic disturb...

Nested case-control designs are inevitably less efficient than full cohort designs, and it is important to use available information as efficiently as possible. Reuse of controls by inverse probability weighting may be one way to obtain efficiency improvements, and it can be particularly advantageous when two or more endpoints are analyzed in the s...

Objective To study associations between hyperemesis gravidarum (HG) and birth outcomes. DesignPopulation-based cohort study. SettingNorway. SampleSingleton births in the Norwegian Birth Registry, 1967-2009 (n=2270363). Methods Multiple logistic regression was applied to study associations between HG and dichotomous outcomes; multiple linear regress...

Hyperemesis gravidarum (HG) characterized by excessive nausea and vomiting in early pregnancy, is reported to be associated with increased risks for low birthweight (LBW), preterm birth (PTB), small-for-gestational-age (SGA) and perinatal death. Conflicting results in previous studies underline the necessity to study HG's potential effect on pregna...

Studies have suggested a link between placental weight, placental weight-to-birth weight ratio (PW/BW) and adult health. Hyperemesis gravidarum (HG) may also have implications for adult health. No studies on HG and placental characteristics have been identified. We therefore explored the relationship between HG, placental weight and the PW/BW-ratio...

Objective: To study associations between Helicobacter pylori exposure and severe hyperemesis gravidarum (HG) among immigrant women in Norway by exploring IgG seropositivity and H. pylori antigens in faeces. Additionally, we investigated whether cytotoxin-associated gene A product (CagA) and vacuolating cytotoxin A (VacA) seropositivity modulated t...

Reuse of controls in a nested case-control (NCC) study has not been considered feasible since the controls are matched to their respective cases. However, in the last decade or so, methods have been developed that break the matching and allow for analyses where the controls are no longer tied to their cases. These methods can be divided into two gr...