Initial management and survival of patients with primary metastatic bladder cancer before the immunotherapy era: a population-based study from Norway.

Before immunotherapy became part of the management of metastatic bladder cancer (mBC), systemic anti-cancer treatment comprised primarily of platinum-based chemotherapy. The objective of this study was to describe the characteristics, the initial management, overall survival (OS) and hospitalisations of patients with mBC before 2018 when immunotherapy for mBC was introduced in Norway.  Material and methods: It is a nationwide population-based study of primary mBC patients (diagnosed 2008-16). Descriptive statistics were applied and stratified for four initial management options (≤150 days after BC diagnosis): chemotherapy, major local treatment (cystectomy/pelvic radiotherapy), multimodal treatment (chemotherapy and local) and no anti-cancer treatment beyond transurethral resection of bladder tumour (untreated). Group differences were evaluated by Chi-square and Kruskal-Wallis test; OS was estimated with Kaplan-Meier. Results: Of the 305 patients included, 76 (25%) patients had chemotherapy, 46 (15%) patients had major local treatment, 21 (7%) patients had multimodal treatment and 162 (53%) patients were untreated.  Median OS ranged from 2.3 months (untreated) to 9.8 months (chemotherapy). Patients who received treatment had a higher rate of hospitalisation, with a median stay of three to four times that of untreated patients. Conclusion: Before immunotherapy, more than 50% of patients with primary mBC did not receive any initial anti-cancer therapy and had a poor survival. Patients treated with chemotherapy had inferior median OS compared to those treated with comparable systemic strategies in contemporary trials. Our results provide a basis for future research on treatment and survival after the introduction of immunotherapy for mBC, aiming to improve the care and outcome of patients with mBC.

Time trends in systemic treatment for patients with metastatic prostate cancer: a national cohort study.

BACKGROUND: Several new systemic treatments for primary metastatic prostate cancer patients (mPCa) were introduced in the last decade for both hormone-sensitive (mHSPC) and castration-resistant prostate cancer (mCRPC). However, little is known about the introduction of these treatments in clinical practice. In this national cohort study, we described users and non-users of systemic treatment beyond androgen deprivation therapy (ADT). We also explored whether there was a shift in treatment patterns after the introduction of Docetaxel for mHSPC patients. MATERIALS AND METHODS: All patients registered in the Cancer Registry of Norway with mPCa diagnosed in 2010-18 were included. Data on systemic therapy (Docetaxel, Abiraterone, Enzalutamide, Cabazitaxel, and Radium-223) were provided from the Norwegian Prescription Database, the Norwegian Patient Registry, and the Norwegian Control and Payment of Health Reimbursement Database. Descriptive results about patient and disease characteristics were presented using frequencies and proportions, means and standard deviations, or medians and interquartile ranges. RESULTS: Of the 2770 patients included in this study, 48% received systemic treatment beyond ADT. The proportion of patients receiving systemic treatment increased during the study period. Systemic treatment users were younger, in better general condition, and had more aggressive tumors than non-users. A treatment shift was observed after 2015, with 48% of patients receiving systemic treatment (mainly Docetaxel) in the mHSPC phase compared to 4% of those diagnosed 2010-14. No significant treatment differences were observed across health regions. CONCLUSIONS: An increasing proportion of patients received systemic treatment during the period 2010-18. However, less than 50% of patients in our study received systemic treatment. In accordance with updated guidelines, Docetaxel was introduced after 2015 with an increasing proportion of patients receiving systemic treatment as mHSPC. Further studies should address the disease course and treatment given to patients who do not receive systemic treatment.

Low-dose aspirin, statins, and metformin and survival in patients with breast cancers: a Norwegian population-based cohort study.

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 ≥ 50 years and diagnosed with BC in 2004-2017, who survived ≥ 12 months after diagnosis (follow-up started 12 months after diagnosis), were identified in the Cancer Registry of Norway. The Norwegian Prescription Database provided information on prescriptions. Multivariable Cox proportional hazard models were used to estimate hazard ratios (HR) and 95% confidence intervals (CI) for the association between post-diagnostic use and BC-specific survival, overall and by oestrogen receptor (ER) status. RESULTS: A total of 26,190 patients were included. Of these, 5324 (20%), 7591 (29%), and 1495 (6%) were post-diagnostic users of low-dose aspirin, statins, and metformin, respectively. The median follow-up was 6.1 years, and 2169 (8%) patients died from BC. HRs for use, compared to no use, were estimated at 0.96 (95% CI 0.85-1.08) for low-dose aspirin (ER+: HR = 0.97, 95% CI 0.83-1.13; ER-: HR = 0.97, 95% CI 0.73-1.29, p value for interaction = 0.562), 0.84 (95% CI 0.75-0.94) for statins (ER+: HR = 0.95, 95% CI 0.82-1.09; ER-: HR = 0.77, 95% CI 0.60-1.00, p value for interaction = 0.259), and 0.70 (95% CI 0.51-0.96) for metformin (compared to use of non-metformin antidiabetics) (ER+: HR = 0.67, 95% CI 0.45-1.01; ER-: HR = 1.62, 95% CI 0.72-3.62, p value for interaction = 0.077). CONCLUSION: We found evidence supporting an association between post-diagnostic use of statins and metformin and survival, in patients with BC. Our findings indicate potential differences according to ER status.

Survival trends for patients with primary metastatic prostate cancer before and after the introduction of new antitumor drugs.

BACKGROUND: During the past two decades, new antitumor drugs (Abiraterone, Enzalutamide, Radium-223, Cabazitaxel, and Docetaxel) have been introduced for treatment of prostate cancer with distant metastases (mPCa). Each drug have demonstrated a survival gain in studies, but little is known about the impact in a general population of mPCa patients. In this study we assessed survival before and after introduction of the new drugs for Norwegian mPCa patients. METHODS: Survival was assessed in 5542 patients with primary mPCa. The patients were diagnosed between 2004 and 2018, identified in the Norwegian Cancer Registry. We also analyzed a subgroup of 2738 patients possibly eligible for treatment with new drugs (age <80 years, WHO performance status ≤2 and not dead within 3 months from diagnosis). We estimated overall (OS) and cause-specific survival (CSS) across three diagnostic time periods reflecting to the drugs' introduction in Norway: Before (2004-2009), "in between" (2010-2014) and after the introduction (2015-2018). We used Kaplan-Meier survival analysis and multivariable Cox regression. RESULTS: Median OS increased from 2.3 years in 2004-2009 to 3.3 years in 2015-2018. 3-year OS improved from 41% in 2004-2009 to 51% in 2015-2018. An earlier diagnostic period, a more advanced T stage, higher ISUP grade group, lower WHO status and higher PSA levels were associated with a lower CSS. Similar results was found for the subgroup. CONCLUSIONS: Median OS of mPCa has increased by one year since 2004 for mPCa patients in Norway. Survival improvement persisted after adjustment for recognized prognostic factors and may be related to the introduction of new drugs in Norway.

Downstaging and survival after Neoadjuvant chemotherapy for bladder cancer in Norway; a population-based study.

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 NAC on DS and OS in Norwegian patients with MIBC. METHODS: Patients in the Cancer Registry of Norway undergoing radical cystectomy (2008-2015) with or without NAC diagnosed with MIBC between 2008 and 2012 were included. Follow-up data were available until 31 December 2019. Logistic regression estimated the odds of DS with NAC, and a Cox model investigated the effect of DS on OS. Cox models, a mediator analysis and an instrumental variable approach were used to investigate the effect of NAC on OS. RESULTS: A total of 575 patients were included. NAC was administered to 82 (14%) patients. Compared to cystectomy only, NAC increased the proportion (43% vs. 22%) and the odds of DS (OR 2.51, CI 1.37-4.60, p = 0.003). Independent of NAC, the proportion of pN0 was higher in patients with DS (89% vs. 60%) and DS yielded a 78% mortality risk reduction (HR 0.22, CI 0.15-0.34, p = 1.9∙10-12), compared to patients without DS. We did not find an association between NAC and OS, neither by Cox regression (HR 1.16, CI 0.80-1.68, p = 0.417) nor by an instrumental variable approach (HR = 0.56, CI = 0.07-4.57, p = 0.586). The mediation analysis (p = 0.026) confirmed an indirect effect of NAC on OS through DS. Limitations include limited information of the primary tumour, details of NAC treatment and treatment indications. CONCLUSIONS: NAC increases the probability of DS and is indirectly associated to OS. DS is related to the absence of regional lymph node metastases and is associated with an OS benefit. Improved staging and biomarkers are needed to identify patients most likely to achieve DS and to benefit from NAC.

Primary versus secondary muscle-invasive bladder cancer: survival after curative treatment.

PURPOSE: To assess if cancer-specific survival (CSS) following curative intent treatment (CIT) for muscle-invasive bladder cancer (MIBC) differs between patients presenting with MIBC (primary) and patients presenting with non-muscle-invasive bladder cancer who progress to MIBC (secondary). METHODS: This study uses data from the Cancer Registry of Norway on patients initially diagnosed with bladder cancer in 2008-2012 and treated with radical cystectomy (RC) or radiotherapy (RT). To ensure a clinically relevant population, we selected patients with a pre-treatment histology confirming muscle-invasion. Survival models were applied to evaluate differences in observed and adjusted CSS by type of MIBC and stratified by type of CIT. Adjustment was made for age group, sex, previous cancer, diagnostic hospital's academic status and geographical region, and type of CIT. RESULTS: We identified 650 eligible patients: 589 (91%) primary MIBC and 61 (9%) secondary MIBC. A total of 556 (86%) patients underwent RC and 94 (14%) RT. The 5-year CSS for primary MIBC was 56% and 59% for secondary MIBC (p = 0.68). The type of MIBC did not impact the risk of bladder cancer death (HR = 0.85, CI = 0.55-1.33, p = 0.48), nor when stratified for CIT (RC: HR = 0.93, CI = 0.57-1.53, p = 0.78); RT: HR = 0.71, CI = 0.24-2.16, p = 0.55). CONCLUSION: This first nation-wide population-based study comparing CSS between primary and secondary MIBC showed no significant difference in survival regardless of type of CIT. Continued surveillance of patients with non-muscle-invasive bladder cancer is necessary to detect early progression to MIBC. Future studies should include molecular and genetic characteristics in addition to detailed clinicopathologic information.

Tumor cell invasion in blood vessels assessed by immunohistochemistry is related to decreased survival in patients with bladder cancer treated with radical cystectomy.

BACKGROUND: Lymphovascular invasion (VI) is an established prognostic marker for many cancers including bladder cancer. There is a paucity of data regarding whether the prognostic significance of lymphatic invasion (LVI) differs from blood vessel invasion (BVI). The aim was to examine LVI and BVI separately using immunohistochemistry (IHC), and investigate their associations with clinicopathological characteristics and prognosis. A secondary aim was to compare the use of IHC with assessing VI on standard HAS (hematoxylin-azophloxine-saffron) sections without IHC. METHODS: A retrospective, population -based series of 292 invasive bladder cancers treated with radical cystectomy (RC) with curative intent at Vestfold Hospital Trust, Norway were reviewed. Traditional histopathological markers and VI based on HAS sections were recorded. Dual staining using D2-40/CD31 antibodies was performed on one selected tumor block for each case. RESULTS: The frequency of LVI and BVI was 32 and 28%, respectively. BVI was associated with features such as higher pathological stages, positive regional lymph nodes, bladder neck involvement and metastatic disease whereas LVI showed weaker or no associations. Both BVI and LVI independently predicted regional lymph node metastases, LVI being the slightly stronger factor. BVI, not LVI predicted higher pathological stages. BVI showed reduced recurrence free (RFS) and disease specific (DSS) survival in uni-and multivariable analyses, whereas LVI did not. On HAS sections, VI was found in 31% of the cases. By IHC, 51% were positive, corresponding to a 64% increased sensitivity in detecting VI. VI assessed without IHC was significantly associated with RFS and DSS in univariable but not multivariable analysis. CONCLUSIONS: Our findings indicate that BVI is strongly associated with more aggressive tumor features. BVI was an independent prognostic factor in contrast to LVI. Furthermore, IHC increases VI sensitivity compared to HAS.

The use of reTURB in T1 bladder cancer: a Norwegian population-based study.

AIM: To evaluate the use of repeat transurethral resection of the bladder (reTURB) in stage T1 bladder cancer and its impact on treatment and survival in a Norwegian population-based cohort. MATERIAL AND METHODS: 1130 patients registered at the Cancer Registry of Norway between 2008 and 2012 with primary urothelial T1 cancer were included. Information on surgical and medical procedures was provided by the Norwegian Patient Registry. Descriptive statistics were used to evaluate characteristics of patients receiving reTURB or not within 12 weeks from primary TURB (primTURB). Survival models identified risk factors and estimated cause-specific survival rates (CSS) adjusted for sex, age, WHO grade, concomitant cis and detrusor muscle at primTURB and treatment. RESULTS: The 648 (57%) T1 patients with reTURB were significantly younger and had more WHO high grade tumors compared to those without reTURB. Of 275 patients without detrusor muscle at primTURB 114 (41%) had no reTURB. Of reTURB patients, 45 (7%) had muscle invasive tumor, 110 (17%) T1 and 378 (58%) Ta, cis or T0. Two-thirds of 81 patients receiving early cystectomy after reTURB had T1 or muscle invasive bladder cancer at reTURB. ReTURB did not impact adjusted CSS, but patients with T1 at reTURB had significantly lower CSS than those with < T1 conditions. CONCLUSIONS: Almost half of the T1 patients did not undergo reTURB as recommended in guidelines. We show that reTURB makes the histology result more reliable with impact on both treatment and survival. Our results support the use of reTURB as recommended by EAU guidelines.

Use of Immunomodulating Drugs and Risk of Cutaneous Melanoma: A Nationwide Nested Case-Control Study.

PURPOSE: Cutaneous melanoma is among the fastest growing malignancies in Norway and ultraviolet radiation (UVR) exposure is the primary environmental risk factor. Immunomodulating drugs can increase skin photosensitivity and suppress immune responses, and by such mechanisms influence melanoma risk. We, therefore, aimed to examine the associations between use of immunomodulating drugs and melanoma risk, at a nationwide population level. PATIENTS AND METHODS: In the Cancer Registry of Norway, we identified all cases aged 18-85 with a first primary cutaneous melanoma diagnosed in 2007-2015 (n=12,106). These were matched to population controls from the Norwegian National Registry 1:10 (n=118,564), on sex and year of birth using risk set sampling. Information on prescribed drugs (2004-2015) was obtained by linkage to the Norwegian Prescription Database (NorPD). Conditional logistic regression was used to estimate rate ratios (RRs) and 95% confidence intervals (CIs) for associations between use of immunomodulating drugs (immunosuppressants and corticosteroids) and melanoma risk, adjusted for ambient UVR and other drug use. RESULTS: Compared with ≤1 prescription, use of ≥8 prescriptions of immunosuppressants was associated with increased risk of melanoma (RR 1.50, 95% CI 1.27, 1.77). Similar associations were found for subgroups of immunosuppressants: drugs typically prescribed to organ transplant recipients (OTRs) (RR 2.02, 95% CI 1.35, 3.03) and methotrexate (RR 1.27, 95% CI 1.04, 1.55). Similar results were found for high levels of cumulative doses and across all histological subtypes. Use of corticosteroids was not associated with melanoma risk. CONCLUSION: We found a positive association between use of immunosuppressants and melanoma risk, with the highest risk seen for drugs prescribed to OTRs. Knowledge about this risk increase is important for physicians and users of these drugs, for intensified surveillance, awareness and cautious sun exposure.

Use of Antidepressants and Risk of Cutaneous Melanoma: A Prospective Registry-Based Case-Control Study.

PURPOSE: Melanoma is the cancer with the most rapidly rising incidence rate in Norway. Although exposure to ultraviolet radiation (UVR) is the major environmental risk factor, other factors may also contribute. Antidepressants have cancer inhibiting and promoting side effects, and their prescription rates have increased in parallel with melanoma incidence. Thus, we aimed to prospectively examine the association between use of antidepressants and melanoma by using nation-wide data from the Cancer Registry of Norway, the National Registry, the Norwegian Prescription Database and the Medical Birth Registry of Norway. PATIENT AND METHODS: All cases aged 18-85 with a primary cutaneous invasive melanoma diagnosed during 2007-2015 (n=12,099) were matched to population controls 1:10 (n=118,467) by sex and year of birth using risk-set sampling. We obtained information on prescribed antidepressants and other potentially confounding drug use (2004-2015). Conditional logistic regression was used to estimate adjusted rate ratios (RRs) and 95% confidence intervals (CIs) for the association between overall and class-specific use of antidepressants and incident melanoma. RESULTS: Compared with ≤1 prescription, ≥8 prescriptions of antidepressants overall were negatively associated with melanoma (RR 0.81 CI 0.75-0.87). Class-specific analyses showed decreased RRs for selective serotonin reuptake inhibitors (RR 0.82 CI 0.73-0.93) and mixed antidepressants (RR 0.77 CI 0.69-0.86). The negative association was found for both sexes, age ≥50 years, residential regions with medium and highest ambient UVR exposure, all histological subtypes, trunk, upper and lower limb sites and local disease. CONCLUSION: Use of antidepressants was associated with decreased risk of melanoma. There are at least two possible explanations for our results; cancer-inhibiting actions induced by the drug and less UVR exposure among the most frequent users of antidepressants.

Identification of potential carcinogenic and chemopreventive effects of prescription drugs: a protocol for a Norwegian registry-based study.

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 induction period. This fact, together with low incidences of many cancer types, limits the usefulness of traditional pharmacovigilance strategies, primarily based on spontaneous reporting of adverse events, to identify associations between drug use and cancer risk. Postmarketing observational pharmacoepidemiological studies are therefore crucial in the evaluation of drug-cancer associations. METHODS AND ANALYSIS: The main data sources in this project will be the Norwegian Prescription Database and the Cancer Registry of Norway. The underlying statistical model will be based on a multiple nested case-control design including all adult (~200 000) incident cancer cases within the age-range 18-85 years from 2007 through 2015 in Norway as cases. 10 cancer-free population controls will be individually matched to these cases with respect to birth year, sex and index date (date of cancer diagnosis). Drug exposure will be modelled as chronic user/non-user by counting prescriptions, and cumulative use by summarising all dispensions' daily defined doses over time. Conditional logistic regression models adjusted for comorbidity (National Patient Register), socioeconomic parameters (Statistics Norway), concomitant drug use and, for female cancers, reproduction data (Medical Birth Registry), will be applied to identify drug-use-cancer-risk associations. ETHICS AND DISSEMINATION: The study is approved by the regional ethical committee and the Norwegian data protection authority. Results of the initial screening step and analysis pipeline will be described in a key paper. Subsequent papers will report the evaluation of identified signals in replication studies. Results will be published in peer-reviewed journals, at scientific conferences and through press releases.

Cardiovascular, antidepressant and immunosuppressive drug use in relation to risk of cutaneous melanoma: a protocol for a prospective case-control study.

INTRODUCTION: The incidence of cutaneous melanoma (hereafter melanoma) has increased dramatically among fair-skinned populations worldwide. In Norway, melanoma is the most rapidly growing type of cancer, with a 47% increase among women and 57% among men in 2000-2016. Intermittent ultraviolet exposure early in life and phenotypic characteristics like a fair complexion, freckles and nevi are established risk factors, yet the aetiology of melanoma is multifactorial. Certain prescription drugs may have carcinogenic side effects on the risk of melanoma. Some cardiovascular, antidepressant and immunosuppressive drugs can influence certain biological processes that modulate photosensitivity and immunoregulation. We aim to study whether these drugs are related to melanoma risk. METHODS AND ANALYSIS: A population-based matched case-control study will be conducted using nation-wide registry data. Cases will consist of all first primary, histologically verified melanoma cases diagnosed between 2007 and 2015 identified in the Cancer Registry of Norway (14 000 cases). Ten melanoma-free controls per case (on date of case melanoma diagnosis) will be matched based on sex and year of birth from the National Registry of Norway. For the period 2004-2015, and by using the unique personal identification numbers assigned to all Norwegian citizens, the case-control data set will be linked to the Norwegian Prescription Database for information on drugs dispensed prior to the melanoma diagnosis, and to the Medical Birth Registry of Norway for data regarding the number of child births. Conditional logistic regression will be used to estimate associations between drug use and melanoma risk, taking potential confounding factors into account. ETHICS AND DISSEMINATION: The project is approved by the Regional Committee for Medical Research Ethics in Norway and by the Norwegian Data Protection Authority. The study is funded by the Southeastern Norway Regional Health Authority. Results will be published in peer-reviewed journals and disseminated further through scientific conferences, news media and relevant patient interest groups.

A correction for sample overlap in genome-wide association studies in a polygenic pleiotropy-informed framework.

BACKGROUND: There is considerable evidence that many complex traits have a partially shared genetic basis, termed pleiotropy. It is therefore useful to consider integrating genome-wide association study (GWAS) data across several traits, usually at the summary statistic level. A major practical challenge arises when these GWAS have overlapping subjects. This is particularly an issue when estimating pleiotropy using methods that condition the significance of one trait on the signficance of a second, such as the covariate-modulated false discovery rate (cmfdr). RESULTS: We propose a method for correcting for sample overlap at the summary statistic level. We quantify the expected amount of spurious correlation between the summary statistics from two GWAS due to sample overlap, and use this estimated correlation in a simple linear correction that adjusts the joint distribution of test statistics from the two GWAS. The correction is appropriate for GWAS with case-control or quantitative outcomes. Our simulations and data example show that without correcting for sample overlap, the cmfdr is not properly controlled, leading to an excessive number of false discoveries and an excessive false discovery proportion. Our correction for sample overlap is effective in that it restores proper control of the false discovery rate, at very little loss in power. CONCLUSIONS: With our proposed correction, it is possible to integrate GWAS summary statistics with overlapping samples in a statistical framework that is dependent on the joint distribution of the two GWAS.

Lack of Association among Peptidyl Arginine Deiminase Type 4 Autoantibodies, PADI4 Polymorphisms, and Clinical Characteristics in Rheumatoid Arthritis.

OBJECTIVE: We aimed to jointly investigate the role of antipeptidyl arginine deiminase type 4 antibodies (anti-PAD4) and polymorphisms in the PADI4 gene together with clinical variables in rheumatoid arthritis (RA). METHODS: Serum IgG autoantibodies to human recombinant PAD4 were identified by DELFIA technique in 745 patients with RA (366 available from previous studies). Genotyping of PADI4 was performed using TaqMan assays in 945 patients and 1118 controls. Clinical data, anticitrullinated protein antibodies (ACPA) status, shared epitope status, and a combined genetic risk score were also available. RESULTS: Anti-PAD4 antibodies were detected in 193 (26%) of 745 patients with RA; 149 (77%) of these were also ACPA-positive. No association was observed between anti-PAD4 status and clinical characteristics, PADI4 polymorphisms, or genetic risk scores after stratification for ACPA status. CONCLUSION: Taken together, the results from these combined serological, genetic, and clinical analyses suggest that anti-PAD4 appears to be a bystander autoantibody with no current clinical utility in RA.

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

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

Vitamin D, obesity and leptin in relation to bladder cancer incidence and survival: prospective protocol study.

INTRODUCTION: Bladder cancer (BC) (including renal pelvis, ureter and urethra) is one of the most common urogenital cancers and the fourth most frequent cancer in men in the USA. In Norway, the incidence of BC has increased over the last decades. The age-standardised incidence rates per 100 000 for 2011-2015 were 53.7 in men and 16.5 in women. Compared to the 5-year period 2006-2010, the percentage increase in incidence was 6.1% in men and 12.3% in women. The recurrence rate of BC is over 50%, the highest recurrence rate of any malignancy. Smoking and occupational exposure to aromatic amines are recognised as the major risk factors. Recently, low-serum level of 25-hydroxy vitamin D (25(OH)D) and obesity have been suggested to increase the BC risk, and leptin, which is important in weight regulation, may be involved in bladder carcinogenesis. More knowledge on potential risk factors for BC is necessary for planning and implementing primary prevention measures. METHODS AND ANALYSES: Cohort and nested case-control studies will be carried out using the population-based Janus Serum Bank Cohort consisting of prediagnostic sera, clinical measurement data (body height and weight, body surface area and weight change over time, blood pressure, cholesterol and triglycerides) and self-reported information on lifestyle factors (smoking, physical activity). Participants were followed from cohort inclusion (1972-2003) through 2014. The cohort will be linked to the Cancer Registry of Norway (cancer data), the National Cause of Death Registry (date and cause of death), National Population Registry (vital status) and Statistic Norway (education and occupation). Serum samples will be analysed for 25(OH)D, vitamin D binding protein, leptin, albumin, calcium and parathyroid hormone. Cox regression and conditional logistic regression models and mediation analysis will be used to estimate association between the exposures and BC. ETHICS AND DISSEMINATION: The study has been approved by the Regional Committee for Medical Research Ethics and is funded by the Norwegian Cancer Society. Results will be published in peer-reviewed journals, at scientific conferences and through press releases.

Intra-individual changes in DNA methylation not mediated by cell-type composition are correlated with aging during childhood.

BACKGROUND: Several studies have reported age-associated changes in DNA methylation in the first few years of life and in adult populations, but the extent of such changes during childhood is less well studied. The goals of this study were to investigate to what degree intra-individual changes in DNA methylation are associated with aging during childhood and dissect the methylation changes directly associated with aging from the effect mediated through variation in cell-type composition (CTC). RESULTS: We performed reduced representation bisulfite sequencing (RRBS) in peripheral whole-blood samples collected at 2, 10, and 16 years of age. We identified age-associated longitudinal changes in DNA methylation at 346 CpGs in 178 genes. Analyses separating the effect mediated by CTC variability across age identified 26 CpGs located in 12 genes that associated directly with age. Hence, the CTC changes across age appear to act as a mediator of the observed DNA methylation associated with age. The results were replicated using EpiTYPER in a second sample set selected from the same cohort. Gene ontology analyses revealed enrichment of transcriptional regulation and developmental processes. Further, comparisons of the mean DNA methylation differences between the time points reveal greater differences between 2 to 10 years and 10 to 16 years, suggesting that the identified age-associated DNA methylation patterns manifests in early childhood. CONCLUSIONS: This study reveals insights into the epigenetic dynamics associated with aging early in life. Such information could ultimately provide clues and point towards molecular pathways that are susceptible to aging-related disease-associated epigenetic dysregulation.

Cell type specific DNA methylation in cord blood: A 450K-reference data set and cell count-based validation of estimated cell type composition.

Epigenome-wide association studies of prenatal exposure to different environmental factors are becoming increasingly common. These studies are usually performed in umbilical cord blood. Since blood comprises multiple cell types with specific DNA methylation patterns, confounding caused by cellular heterogeneity is a major concern. This can be adjusted for using reference data consisting of DNA methylation signatures in cell types isolated from blood. However, the most commonly used reference data set is based on blood samples from adult males and is not representative of the cell type composition in neonatal cord blood. The aim of this study was to generate a reference data set from cord blood to enable correct adjustment of the cell type composition in samples collected at birth. The purity of the isolated cell types was very high for all samples (>97.1%), and clustering analyses showed distinct grouping of the cell types according to hematopoietic lineage. We explored whether this cord blood and the adult peripheral blood reference data sets impact the estimation of cell type composition in cord blood samples from an independent birth cohort (MoBa, n = 1092). This revealed significant differences for all cell types. Importantly, comparison of the cell type estimates against matched cell counts both in the cord blood reference samples (n = 11) and in another independent birth cohort (Generation R, n = 195), demonstrated moderate to high correlation of the data. This is the first cord blood reference data set with a comprehensive examination of the downstream application of the data through validation of estimated cell types against matched cell counts.

Maternal plasma folate impacts differential DNA methylation in an epigenome-wide meta-analysis of newborns.

Folate is vital for fetal development. Periconceptional folic acid supplementation and food fortification are recommended to prevent neural tube defects. Mechanisms whereby periconceptional folate influences normal development and disease are poorly understood: epigenetics may be involved. We examine the association between maternal plasma folate during pregnancy and epigenome-wide DNA methylation using Illumina's HumanMethyl450 Beadchip in 1,988 newborns from two European cohorts. Here we report the combined covariate-adjusted results using meta-analysis and employ pathway and gene expression analyses. Four-hundred forty-three CpGs (320 genes) are significantly associated with maternal plasma folate levels during pregnancy (false discovery rate 5%); 48 are significant after Bonferroni correction. Most genes are not known for folate biology, including APC2, GRM8, SLC16A12, OPCML, PRPH, LHX1, KLK4 and PRSS21. Some relate to birth defects other than neural tube defects, neurological functions or varied aspects of embryonic development. These findings may inform how maternal folate impacts the developing epigenome and health outcomes in offspring.