Prediagnostic circulating levels of sex hormones and survival in esophageal adenocarcinoma.

Sex hormonal differences may contribute to the strong male predominance in esophageal adenocarcinoma (EAC), but whether sex hormone levels influence survival in EAC is unstudied. Our study aimed to assess associations between prediagnostic sex hormone levels and survival in EAC. In a population-based cohort study, 244 male EAC patients from the Janus Serum Bank Cohort in Norway were followed up through 2018. Associations between prediagnostic serum levels of 12 sex hormone measures and disease-specific mortality were assessed using multivariable Cox regression, providing hazard ratios (HR) with 95% confidence intervals (CI) adjusted for age, calendar year, body mass index, tobacco smoking, physical activity and surgical resection. Higher levels of sex hormone-binding globulin (SHBG) indicated decreased disease-specific mortality (HR 0.68, 95% CI 0.44-1.07, highest vs lowest tertile). In stratified analyses by surgery, such associations remained in nonoperated patients (HR 0.58, 95% CI 0.35-0.96, highest vs lowest tertile), but not in operated patients. Higher levels of follicle-stimulating hormone (FSH) were associated with increased disease-specific mortality in an exposure-response pattern; HRs for the middle and highest tertiles vs the lowest tertile were 1.35 (95% CI 0.89-2.05) and 1.61 (95% CI 1.06-2.43), respectively. No clear associations were observed with serum levels of dehydroepiandrosterone sulfate, luteinizing hormone, prolactin, testosterone, 17-OH-progesterone, progesterone, estradiol, androstenedione, testosterone:estradiol ratio or free testosterone index. These findings suggest that higher endogenous levels of SHBG and lower levels of FSH may increase the survival in EAC. The other 10 examined sex hormone measures may not influence the survival.

Circulating Sex Hormone Levels and Risk of Esophageal Adenocarcinoma in a Prospective Study in Men.

OBJECTIVES: Sex hormones have been hypothesized to explain the strong male predominance in esophageal adenocarcinoma, but evidence is needed. This study examined how circulating sex hormone levels influence future risk of esophageal adenocarcinoma. METHODS: This case-control study was nested in a prospective Norwegian cohort (Janus Serum Bank Cohort), including 244 male patients with esophageal adenocarcinoma and 244 male age-matched control participants. Associations between prediagnostic circulating levels of 12 sex hormones and risk of esophageal adenocarcinoma were assessed using conditional logistic regression. In addition, a random-effect meta-analysis combined these data with a similar prospective study for 5 sex hormones. RESULTS: Decreased odds ratios (ORs) of esophageal adenocarcinoma were found comparing the highest with lowest quartiles of testosterone (OR = 0.44, 95% confidence interval [CI] 0.22-0.88), testosterone:estradiol ratio (OR = 0.37, 95% CI 0.19-0.72), and luteinizing hormone (OR = 0.50, 95% CI 0.30-0.98), after adjustment for tobacco smoking and physical activity. These associations were attenuated after further adjustment for body mass index (OR = 0.56, 95% CI 0.27-1.13 for testosterone; OR = 0.46, 95% CI 0.23-0.91 for testosterone:estradiol ratio; OR = 0.55, 95% CI 0.29-1.08 for luteinizing hormone). No associations were observed for sex hormone-binding globulin, dehydroepiandrosterone sulfate, follicle-stimulating hormone, prolactin, 17-OH progesterone, progesterone, androstenedione, or free testosterone index. The meta-analysis showed an inverse association between testosterone levels and risk of esophageal adenocarcinoma (pooled OR for the highest vs lowest quartile = 0.60, 95% CI 0.38-0.97), whereas no associations were identified for androstenedione, sex hormone-binding globulin, estradiol, or testosterone:estradiol ratio. DISCUSSION: Higher circulating testosterone levels may decrease the risk of esophageal adenocarcinoma in men.

Competitive learning suggests circulating miRNA profiles for cancers decades prior to diagnosis.

MicroRNAs are regulators of gene expressionand may be key markers in liquid biopsy.Early diagnosis is an effective means to increase patients' overall survival. We generated genome-wide miRNA profiles from serum of patients and controls from the population-based Janus Serum Bank (JSB) and analysed them by bioinformatics and artificial intelligence approaches. JSB contains sera from 318,628 originally healthy persons, more than 96,000 of whom developed cancer. We selected 210 serum samples from patients with lung, colon or breast cancer at three time points prior to diagnosis (up to 32 years prior to diagnosis with median 5 years interval between TPs), one time-point after diagnosis and from individually matched controls. The controls were matched on age and year of all pre-diagnostic sampling time-points for the corresponding case. Using ANOVA we report 70 significantly deregulated markers (adjusted p-value<0.05). The driver for the significance was the diagnostic time point (miR-575, miR-6821-5p, miR-630 with adjusted p-values<10-10). Further, 91miRNAs were differently expressed in pre-diagnostic samples as compared to controls (nominal p < 0.05). Self-organized maps (SOMs)indicated larges effects in lung cancer samples while breast cancer samples showed the least pronounced changes. SOMsalsohighlighted cancer and time point specific miRNA dys-regulation. Intriguingly, a detailed breakdown of the results highlighted that 51% of all miRNAs were highly specific, either for a time-point or a cancer entity. Pathway analysis highlighted 12 pathways including Hipo signalling and ABC transporters.Our results indicate that tumours may be indicated by serum miRNAs decades prior the clinical manifestation.

Circulating isoflavone and lignan concentrations and prostate cancer risk: a meta-analysis of individual participant data from seven prospective studies including 2,828 cases and 5,593 controls.

Phytoestrogens may influence prostate cancer development. This study aimed to examine the association between prediagnostic circulating concentrations of isoflavones (genistein, daidzein, equol) and lignans (enterolactone and enterodiol) and the risk of prostate cancer. Individual participant data were available from seven prospective studies (two studies from Japan with 241 cases and 503 controls and five studies from Europe with 2,828 cases and 5,593 controls). Because of the large difference in circulating isoflavone concentrations between Japan and Europe, analyses of the associations of isoflavone concentrations and prostate cancer risk were evaluated separately. Prostate cancer risk by study-specific fourths of circulating concentrations of each phytoestrogen was estimated using multivariable-adjusted conditional logistic regression. In men from Japan, those with high compared to low circulating equol concentrations had a lower risk of prostate cancer (multivariable-adjusted OR for upper quartile [Q4] vs. Q1 = 0.61, 95% confidence interval [CI] = 0.39-0.97), although there was no significant trend (OR per 75 percentile increase = 0.69, 95 CI = 0.46-1.05, ptrend = 0.085); Genistein and daidzein concentrations were not significantly associated with risk (ORs for Q4 vs. Q1 = 0.70, 0.45-1.10 and 0.71, 0.45-1.12, respectively). In men from Europe, circulating concentrations of genistein, daidzein and equol were not associated with risk. Circulating lignan concentrations were not associated with the risk of prostate cancer, overall or by disease aggressiveness or time to diagnosis. There was no strong evidence that prediagnostic circulating concentrations of isoflavones or lignans are associated with prostate cancer risk, although further research is warranted in populations where isoflavone intakes are high.

Sources to variability in circulating human miRNA signatures.

An increasing number of studies propose circulating microRNAs (miRNAs) as biomarkers for a large number of human diseases including cancer, cardiovascular diseases, neurologic pathologies and others. To further validate miRNA as biomarkers it is indispensable to understand the variability of circulating miRNAs in healthy individuals. We determined the longitudinal miRNomes of 90 serum samples from the Janus Serum Bank in Norway, which have been stored between 23 and 40 y at -25 °Celsius. We profiled 3 serum samples with microarrays for 30 individuals, each. For each individual the samples were collected with a time interval of approximately 5 y. This design allowed insights into inter-individual variability, age dependent miRNA variability and the impact of storage length and pre-processing. A significant proportion of the miRNome was affected by the age of the blood donor and a not negligible, albeit small, part of the miRNome by the storage time. A substantial part of miRNAs was differentially abundant between individuals, independent of the time when samples were collected. Stepwise filtering of the 529 miRNAs that were detected in the serum samples showed 168 miRNAs with differential abundance depending on the time point analyzed, 56 miRNAs differentially abundant between individuals, and 169 miRNAs with an abundance depending on the sampling procedure. While these groups of miRNAs contain generally interesting and biologically important miRNAs, the remaining 135 miRNAs constitute very promising biomarker candidates as they show an overall low variability between healthy individuals, a likewise overall low variability across a longer life span, and a high independence of the sampling process and the storage length.

Effect of multiple freeze-thaw cycles on selected biochemical serum components.

BACKGROUND: To maintain the best performance a frozen serum sample should be thawed once to prevent repeated freeze-thaw cycles. Archival biobanks often have one tube of a sample available, causing repeated freeze-thaw cycles when the sample is used in multiple research projects. In this study, we investigated potential effects of freeze-thaw cycles on several biochemical components in serum. METHODS: Serum from 40 fasting donors of both genders, aged 30-60 years, were frozen at -25 °C. Aliquots of the 40 different samples went through 1, 2, 3, 4, 5 and 10 thaws, respectively. They were analyzed after 3 month of storage for 15 serum components including electrolytes and metabolites, proteins and enzymes, lipids, hormones and vitamins. One-way analyses of variance (ANOVA) with repeated measurements and equivalence tests were used to examine differences in component levels. RESULTS: Albumin, aspartate-aminotransferase (ASAT), cholesterol, creatinine, C-reactive protein, glucose, immunoglobulin G, potassium, testosterone, triglycerides, urea and vitamin B12 levels did not show significant difference for pairwise comparisons after 10 repeated thaws. Although albumin, ASAT, bilirubin, potassium, sodium, testosterone and thyroid stimulating hormone (TSH) showed overall statistically significant changes in serum levels, only bilirubin, sodium and TSH were significant for the pairwise comparisons investigated. Clinical significance were shown for albumin, ASAT, bilirubin, sodium and testosterone. CONCLUSIONS: Twelve components (albumin, ASAT, cholesterol, creatinine, C-reactive protein, glucose, immunoglobulin G, potassium, testosterone, triglycerides, urea and vitamin B12) were robust to 10 repeated thaws compared to baseline level. Three components (bilirubin, sodium and TSH) showed statistical significant difference for pairwise comparisons, however, TSH was not clinically affected.

Longitudinal biobanks-based study on the joint effects of infections, nutrition and hormones on risk of prostate cancer.

Background To evaluate the individual and combined effects of enterolactone, vitamin D, free testosterone, Chlamydia trachomatis and HPV-18 on the risk of prostate cancer in a large population-based biochemical material that combined three Nordic serum sample banks. Material and methods A joint cohort of 209 000 healthy men was followed using cancer registry linkages. From this cohort altogether 699 incident cases of prostate cancer were identified. Four controls were selected by incidence density sampling and matching for country, age and date of the blood sampling. Complete data for all investigated exposures was available for 483 eligible cases and 1055 eligible controls. Multivariate regression analyses were performed to investigate the solitary and combined effects. Results The solitary effects were small. Significantly increased risk [rate ratio 1.6 (95% CI 1.0-2.5)] was found in those seronegative for C. trachomatis infection. The joint effect in risk levels of enterolactone and vitamin D was antagonistic [observed rate ratio (RR) 1.4 (1.0-2.1), expected RR 2.0 (1.0-4.1)] as well as that of HPV-18 and C. trachomatis [observed RR 1.9 (0.8-4.5), expected RR 9.9 (1.1-87.0)]. Conclusion A large follow-up study combining data from several previously investigated exposures to investigate joint effects found no evidence that exposure to two risk factors would increase the risk of prostate cancer from that expected on basis of exposure to one risk factor. If anything, the results were consistent with antagonistic interactions.

HE4 as an Early Detection Biomarker of Epithelial Ovarian Cancer: Investigations in Prediagnostic Specimens From the Janus Serumbank.

OBJECTIVES: Epithelial ovarian cancer is characterized by nonspecific signs and clinical symptoms arising at late stages. Early detection is therefore important and may significantly improve the survival rate. Cancer antigen 125 (CA125) has been the most extensively studied serum biomarker in epithelial ovarian cancer, but low specificity limits its usefulness. A relatively novel biomarker, human epididymis protein 4 (HE4), has shown promise in early detection of the disease. The aim of this study was to investigate how early the tumor marker increases before diagnosis. METHODS/MATERIALS: A nested case-control design was used to evaluate the performance of HE4 and CA125 in prediagnostic serum samples from the Janus Serumbank. Serial specimens from 120 women with invasive epithelial ovarian cancer were compared with healthy controls. Serum level of CA125, HE4, and cotinine was measured. Spearman correlation and multiple linear regression analyses were used to investigate impact of smoking, age, storage time, and lag time (time from sampling until date of diagnosis). RESULTS: Spearman correlation showed a strong positive correlation between HE4 and smoking in both cases and controls. Multiple linear regression analyses for pairwise differences between case and control showed that serum level of HE4 and CA125 was significantly increased (P = 0.002 and P < 0.001, respectively) 2 years before diagnosis and that CA125 also was significantly increased up to 4 years before diagnosis (P = 0.002). CONCLUSIONS: The present study showed that a difference between cases and controls in serum concentration of HE4 seemed to be increased 2 years before diagnosis and that CA125 was increased until 4 years before diagnosis.

Prospective study of genital human papillomaviruses and nonmelanoma skin cancer.

Genital high-risk human papillomaviruses (HPVs) cause cervical cancer and are also found in a small proportion of nonmelanoma skin cancers (NMSCs). We used cancer registry linkages to follow the 856,000 serum donors included in the Southern Sweden Microbiology Biobank or the Janus Biobank in Norway, for incident skin cancers occurring up to 30 years after serum donation. Serum samples taken before diagnosis of squamous cell carcinoma (SCC) (N = 633), basal cell carcinoma (BCC) (N = 1990) or other NMSC (N = 153) and matched samples from control donors were tested for antibodies to the genital HPV types 16 and 18. Both HPV 16 and 18 were associated with increased risk for SCC [odds ratio (OR) 1.6, 95% confidence interval (CI) 1.1-2.6 and OR 1.7, 95% CI 1.1-2.5, respectively] and other NMSC (OR 2.3, 95% CI 1.0-5.2 and OR 3.5, 95% CI 1.4-8.7, respectively), but not for BCC. Tumor blocks from HPV16 or 18 seropositive cases were tested with real-time polymerase chain reaction for presence of HPV16 or 18 DNA. No HPV18 DNA was found and only four of 79 SCC cases (two of which were from the perineum/perianal area), one of 221 BCC cases and zero of five cases with other NMSC contained HPV16 DNA. In conclusion, we found prospective evidence that HPV16 and 18 antibodies associate with SCC and other NMSC risk, but not with BCC risk. As only a small proportion of seropositive subjects had evidence of the corresponding HPV DNA in the tumor, most of this excess risk is likely to be due to confounders associated with genital HPV infection.

Prospective study of human papillomavirus seropositivity and risk of nonmelanoma skin cancer.

Cutaneous human papillomaviruses (HPVs) have been associated with squamous cell carcinoma (SCC) in case-control studies, but there are limited data from prospective studies assessing whether virus exposure predicts risk of future cancer development. Two major biobanks, the Southern Sweden Microbiology Biobank (1971-2003) and the Janus Biobank (1973-2003) in Norway, containing samples from 850,000 donors, were searched for incident skin cancer for up to 30 years using registry linkages. Altogether, 2,623 donors with samples taken before diagnosis of SCC or basal cell carcinoma (BCC) of the skin were identified. Prediagnostic samples and samples from 2,623 matched controls were tested for antibodies against 33 types of HPV. Baseline seropositivity to HPV types in genus ß species 2 was associated with SCC risk (odds ratio = 1.3, 95% confidence interval: 1.1, 1.7); this was also the case for samples taken more than 18 years before diagnosis (odds ratio = 1.8, 95% confidence interval: 1.1, 2.8). Type-specific persistent seropositivity entailed elevated point estimates for SCC risk for 29 HPV types and decreased point estimates for only 3 types. After multiple hypothesis adjustment, HPV 76 was significantly associated with SCC risk and HPV 9 with BCC risk. In summary, seropositivity for certain HPV types was associated with an increased risk for future development of SCC and BCC.

Kinetic modeling of storage effects on biomarkers related to B vitamin status and one-carbon metabolism.

BACKGROUND: Biomarkers and metabolites related to B vitamin function and one-carbon metabolism have been studied as predictors of chronic diseases in studies based on samples stored in biobanks. For most biomarkers, stability data are lacking or fragmentary. METHODS: Degradation and accumulation kinetics of 32 biomarkers were determined at 23 °C in serum and plasma (EDTA, heparin, and citrate) collected from 16 individuals and stored for up to 8 days. In frozen serum (-25 °C), stability was studied cross-sectionally in 650 archival samples stored for up to 29 years. Concentration vs time curves were fitted to monoexponential, biexponential, linear, and nonlinear models. RESULTS: For many biomarkers, stability was highest in EDTA plasma. Storage effects were similar at room temperature and at -25 °C; notable exceptions were methionine, which could be recovered as methionine sulfoxide, and cystathionine, which decreased in frozen samples. Cobalamin, betaine, dimethylglycine, sarcosine, total homocysteine, total cysteine, tryptophan, asymetric and symmetric dimethyl argenine, creatinine, and methylmalonic acid were essentially stable under all conditions. Most B vitamins (folate and vitamins B2 and B6) were unstable; choline increased markedly, and some amino acids also increased, particularly in serum. The kynurenines showed variable stability. For many biomarkers, degradation (folate and flavin mononucleotide) or accumulation (pyridoxal, riboflavin, choline, amino acids) kinetics at room temperature were non-first order. CONCLUSIONS: Data on stability and deterioration kinetics for individual biomarkers are required to optimize procedures for handling serum and plasma, and for addressing preanalytical bias in epidemiological and clinical studies.

Stability of testosterone measured in male archival serum samples by two different methods.

OBJECTIVE: To investigate testosterone stability in archival serum samples stored for etiological cancer research, and compare two methods for testosterone measurements. DESIGN AND MEASUREMENTS: Four sets of 130 serum samples were randomly selected from male blood donors, aged 40-49 years at the time of blood draw. The sets had been stored at -25°C for 1 month, 4, 17 and 29 years, respectively, and were analyzed for testosterone, sex hormone binding globuline, follicle stimulating hormone, luteinizing hormone, sodium, albumin and cotinine. Testosterone was measured by two methods, an electrochemiluminescence immunoassay, and a liquid chromatography tandem mass spectrometry method. RESULTS: The mean level of testosterone in the samples with the longest storage time (29 years) was substantially higher than that of the fresh samples. The two techniques gave approximately equal results for testosterone values in the range 5-27.5 nmol/L, close to normal range. CONCLUSIONS: The high mean levels of testosterone in the oldest samples suggest a downward trend over the last three decades, as any degradation during storage would tend to give the opposite result. For archival serum samples, both electrochemiluminescence immunoassay and liquid chromatography tandem mass spectrometry are applicable methods for measurement of testosterone within the expected reference range.

Stable serum miRNA profiles as potential tool for non-invasive lung cancer diagnosis.

Circulating microRNAs in human serum have increasingly been recognized as stable markers for cancer detection. However, there is still a lack of miRNome wide studies over a long period of time with respect to pathogenic processes. We obtained serum samples from the janus serum bank collected prior and after diagnosis of lung cancer. We analyzed the abundance of 904 miRNAs in serum from eight cancer patients at three time points and from six healthy control individuals. Based on the identified miRNA signatures, hierarchical clustering and a self-organizing map identified three major clusters including one cluster containing most of the of the pre-diagnostic samples, a second cluster with mainly post-diagnostic samples, and a third cluster with mainly control samples. Correlation analyses showed that although the profiles were generally stable over several years, most obvious changes of the miRNA pattern seem to occur at a time close to diagnosis. Our findings support the idea that a developing lung cancer might be detectable years prior to diagnosis through a specific miRNA signature and that this signature changes during tumor development.

A Simple and Cost-Effective Method for Measuring Hemolysis in Biobank Serum Specimens.

Background: During sampling and processing, blood samples can be affected by hemolysis. Information is lacking regarding hemolysis for biobank samples. There is a need for a method that can easily measure hemoglobin as an indicator of hemolysis in stored samples before they are included in research projects. In this study we present a simple method for estimating hemolysis and investigate the effect of centrifugation speeds and temperatures on sample turbidity that commonly interferes with measurements. Methods: Using a variation of the Beer-Lambert law, we quantified the hemoglobin concentration in 75 long-term stored samples at a wavelength of 414 nm with a NanoDrop™ 8000 spectrophotometer. Owing to interference from turbidity, the samples underwent different treatments post-thawing: centrifugation at 10,000 and 20,000 g at two different temperatures (4°C and 19°C) for 15 minutes. In addition, freshly collected serum samples (n = 20) underwent a single freeze-thaw cycle, with hemoglobin measured prefreeze, post-thaw, and postcentrifugation. Kruskal-Wallis rank sum test groups and pairwise Wilcoxon rank test were used for statistical analysis. Results: A strong effect of centrifugation on the turbidity was shown for the long-term stored samples, however, this effect was independent of the temperature or centrifugation speeds. Centrifugation at 20,000 g for 15 minutes at 19°C reduced the turbidity up to 50%. A single freeze-thaw cycle in the fresh samples increased the optical density at 414 nm slightly, indicating a false increase of hemoglobin concentration. The following centrifugation reduced the concentration to less than the initial sample measurements, suggesting the presence of interference immediately after sampling. Conclusion: We describe here a simple and cost-effective NanoDrop-based method for measuring hemolysis levels intended for use in biobank facilities. We found that centrifugation, but not temperature, is a crucial step to reduce interference from turbidity.

Prediagnostic Serum 25-Hydroxyvitamin D and Mortality Among Bladder Cancer Patients in the Janus Serum Bank Cohort.

PURPOSE: Circulating 25-hydroxyvitamin D (25(OH)D) is inversely associated with overall cancer mortality and selected cancers, while for urothelial bladder cancer (BC) this relationship is unclear. We aimed to examine the association between 25(OH)D and BC mortality. MATERIALS AND METHODS: We used prediagnostic serum from 378 BC cases within the population-based Janus Cohort. Cox regression models estimated hazard ratios (HRs), with 95% confidence intervals (CIs), for the association between 25(OH)D and BC-specific and all-cause mortality. Restricted cubic splines were assessed to examine non-linear risk associations. Analyses were stratified by tumor invasiveness (non-muscle invasive BC (NMIBC) and muscle invasive BC (MIBC)). Additionally, the association between 25(OH)D and all-cause mortality was assessed for 378 cancer-free matched controls. RESULTS: 25(OH)D deficiency (<50 nmol/L) was associated with higher BC-specific mortality (HR 1.87, 95% CI 1.10-3.20), when compared with insufficient levels (50-74 nmol/L). Stratification by tumor invasiveness revealed that this result was evident for NMIBC only, both with respect to BC-specific mortality (HR 2.84, 95% CI 1.14-7.12) and all-cause mortality (HR 1.97, 95% CI 1.06-3.65). No association between 25(OH)D levels and all-cause mortality was found in cancer-free controls. CONCLUSION: 25(OH)D deficiency (<50 nmol/L) prior to a BC diagnosis was associated with increased risk of BC-specific mortality, when compared to insufficient levels (50-74 nmol/L). The results were evident among NMIBC patients only, suggesting a more critical role of vitamin D deficiency in an early stage of the disease.

Vitamin D and Vitamin D-binding protein and risk of bladder cancer: A nested case-control study in the Norwegian Janus Serum Bank Cohort.

BACKGROUND: High circulating levels of vitamin D (25(OH)D) are suggested to reduce the risk of urinary bladder cancer (BC), but the evidence is weak, and several studies lack sufficient adjustment for potential confounders (e.g., smoking, body mass index (BMI), and physical activity). Moreover, few studies have investigated the role of vitamin D-binding protein (DBP) in this context. We conducted a matched nested case-control study including 378 cases and 378 controls within the Norwegian population-based Janus cohort, using serum collected 5-41 years prior to diagnosis, to study 25(OH)D and BC risk, by taking circulating DBP into account. METHODS: Cox regression models were used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs), for 25(OH)D, DBP, and the molar ratio of 25(OH)D:DBP, an estimate of unbound (free) 25(OH)D levels. We adjusted for smoking (status and pack-years), BMI, physical activity, education and (mutually) for 25(OH)D and DBP. Restricted cubic splines were employed to examine nonlinear associations. RESULTS: High optimal levels of circulating 25(OH)D (≥100 nmol/L) (HR 0.35, 95% CI 0.19-0.64) were associated with decreased BC risk, when compared with insufficient concentrations (50-74 nmol/L). This association was less pronounced for optimal levels (75-99 nmol/L) (HR = 0.69, 95% CI 0.47-1.01). Moreover, estimated free 25(OH)D, was associated with decreased BC risk for molar ratio 17-21 (HR 0.66, 95% CI 0.44-0.97) and ≥22 (HR 0.50, 95% CI 0.29-0.82), compared to molar ratio 11-16. The HR function for BC risk was not linear, rather reversed u-shaped, with the highest HR at 62.5 nmol/L and 13.5 molar ratio, respectively. CONCLUSION: High levels of total and estimated free 25(OH)D were associated with reduced risk of BC, compared with insufficient concentrations. DBP was not associated with BC risk. We did not observe any impact of DBP or any of the studied lifestyle factors on the association between 25(OH)D and BC.

Analytical recovery of folate and its degradation products in human serum stored at -25 degrees C for up to 29 years.

Epidemiological studies on folate and chronic diseases often involve the use of frozen serum stored in biorepositories for decades. Folate instability may attenuate associations between folate status and study endpoints. In this cross-sectional study, we retrieved serum samples stored at -25 degrees C for 0, 4, 6, 17, or 29 y in the Janus biobank. Samples were obtained from a total of 650 men aged 40-49 y at the time of blood collection and were evenly distributed according to storage time. Folate was determined by a liquid chromatography tandem MS (LC-MS/MS) assay that measures 5-methyltetrahydrofolate (5mTHF), its oxidation product 4-alpha-hydroxy-5-methyltetrahydrofolate (hmTHF), and other folate species; by a Lactobacillus rhamnosus microbiological assay; and by LC-MS/MS as p-aminobenzoylglutamate (pABG) equivalents after oxidation and mild acid hydrolysis of the folate species. Concentrations of 5mTHF and microbiologically active folate were lower in samples that had been subjected to long-term storage and the data were consistent with a decrease of 3.2 and 2.8%/y, respectively. hmTHF was detected in all specimens but did not accumulate upon long-term storage (>4 y). Folate measured as pABG declined at a slow rate of 0.98%/y and approximately 80% of the folate was recovered after 29 y of storage. B-vitamin status did not differ between individuals delivering samples at different time points, as assessed by measuring total homocysteine, methylmalonic acid, and serum vitamin B-12. In conclusion, folate is substantially degraded in serum frozen for decades but can to a large extent be recovered as pABG equivalents. The pABG assay appears to be the method of choice for the determination of folate status in archival serum samples.

Lifestyle associated factors and risk of urinary bladder cancer: A prospective cohort study from Norway.

A number of lifestyle associated factors, such as high body mass index (BMI), low physical activity, and related metabolic disorders, are associated with increased risk of cancer at several sites. For urinary bladder cancer (BC), such studies show inconsistent results, which could result from inadequate adjustment for smoking and occupational exposure. In the population-based Janus Cohort (n = 292 851), we investigated the independent and combined impact of BMI, physical activity, blood pressure, and blood lipids on the risk of BC, by thorough adjustment for smoking and potential occupational exposure. We used cox proportional hazard regression to estimate hazard ratios (HRs) with 95% confidence intervals (CIs) for the associations between the lifestyle associated factors and BC risk. The associations observed were dependent on smoking status and gender. Among men, diastolic blood pressure (DBP) (HR 1.07, 95% CI 1.02-1.12) and systolic blood pressure (SBP) (HR 1.04, 95% CI 1.01-1.07) were positively associated with BC risk. Stratification by smoking status revealed a positive association between DBP and BC risk in never smokers (HR 1.14, 95% CI 1.00-1.30), while no association was seen for current and former smokers. A risk score, integrating information across the lifestyle factors was positively associated with BC risk in men (ptrend  = 0.043). In women, physical activity was associated with a decreased BC risk, but only among never smokers (HR 0.65, 95% CI 0.45-0.94). In conclusion, relations between lifestyle associated factors and BC risk were most evident in never smokers, suggesting that smoking dominates the relation in current smokers.

Ultralow amounts of DNA from long-term archived serum samples produce quality genotypes.

While genotyping studies are scavenging for suitable samples to analyze, large serum collections are currently left unused as they are assumed to provide insufficient amounts of DNA for array-based genotyping. Long-term stored serum is considered to be difficult to genotype since preanalytical treatments and storage effects on DNA yields are not well understood. Successful genotyping of such samples has the potential to activate large biobanks for future genome-wide association studies (GWAS). We aimed to evaluate genotyping of ultralow amounts of DNA from samples stored up to 45 years in the Janus Serum Bank with two commercially available platforms. 64 samples, with various preanalytical treatments, were genotyped on the Axiom Array from Thermo Fisher Scientific and a subset of 24 samples with slightly higher yield were genotyped on the HumanCoreExome array from Illumina. Our results showed that about 80% of the serum samples produced call rates with the Axiom arrays that would be satisfactory in GWAS. The mean DNA yield was 5.8 ng as measured with PicoGreen, 3-6% of recommended yield. The failed samples had on average lower input amounts of DNA. All serum samples genotyped on the HumanCoreExome with a standard and FFPE protocol produced GWAS satisfactory call rates, with mean 97.57% and 98.35% call rates, respectively. The mean yield was 10.65 ng, 6% of the recommendations. Successful array-based genotyping of ultralow DNA yields from serum samples stored up to 45 years is possible. These results demonstrate the potential to activate large serum biobank collections for future studies.

Identification and Validation of Leucine-rich α-2-glycoprotein 1 as a Noninvasive Biomarker for Improved Precision in Prostate Cancer Risk Stratification.

BACKGROUND: More accurate risk assessments are needed to improve prostate cancer management. OBJECTIVE: To identify blood-based protein biomarkers that provided prognostic information for risk stratification. DESIGN SETTING AND PARTICIPANTS: Mass spectrometry was used to identify biomarker candidates from blood, and validation studies were performed in four independent cohorts retrospectively collected between 1988 and 2015. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: The primary outcome objectives were progression-free survival, prostate cancer-specific survival (PCSS), and overall survival. Statistical analyses to assess survival and model performance were performed. RESULTS AND LIMITATION: Serum leucine-rich α-2-glycoprotein 1 (LRG1) was found to be elevated in fatal prostate cancer. LRG1 provided prognostic information independent of metastasis and increased the accuracy in predicting PCSS, particularly in the first 3 yr. A high LRG1 level is associated with an average of two-fold higher risk of disease-progression and mortality in both high-risk and metastatic patients. However, our study design, with a retrospective analysis of samples spanning several decades back, limits the assessment of the clinical utility of LRG1 in today's clinical practice. Thus, independent prospective studies are needed to establish LRG1 as a clinically useful biomarker for patient management. CONCLUSIONS: High blood levels of LRG1 are unfavourable in newly diagnosed high-risk and metastatic prostate cancer, and LRG1 increased the accuracy of risk stratification of prostate cancer patients. PATIENT SUMMARY: High blood levels of leucine-rich α-2-glycoprotein 1 are unfavourable in newly diagnosed high-risk and metastatic prostate cancer.