A scoping review of statistical methods in studies of biomarker-related treatment heterogeneity for breast cancer.

BACKGROUND: Many scientific papers are published each year and substantial resources are spent to develop biomarker-based tests for precision oncology. However, only a handful of tests is currently used in daily clinical practice, since development is challenging. In this situation, the application of adequate statistical methods is essential, but little is known about the scope of methods used. METHODS: A PubMed search identified clinical studies among women with breast cancer comparing at least two different treatment groups, one of which chemotherapy or endocrine treatment, by levels of at least one biomarker. Studies presenting original data published in 2019 in one of 15 selected journals were eligible for this review. Clinical and statistical characteristics were extracted by three reviewers and a selection of characteristics for each study was reported. RESULTS: Of 164 studies identified by the query, 31 were eligible. Over 70 different biomarkers were evaluated. Twenty-two studies (71%) evaluated multiplicative interaction between treatment and biomarker. Twenty-eight studies (90%) evaluated either the treatment effect in biomarker subgroups or the biomarker effect in treatment subgroups. Eight studies (26%) reported results for one predictive biomarker analysis, while the majority performed multiple evaluations, either for several biomarkers, outcomes and/or subpopulations. Twenty-one studies (68%) claimed to have found significant differences in treatment effects by biomarker level. Fourteen studies (45%) mentioned that the study was not designed to evaluate treatment effect heterogeneity. CONCLUSIONS: Most studies evaluated treatment heterogeneity via separate analyses of biomarker-specific treatment effects and/or multiplicative interaction analysis. There is a need for the application of more efficient statistical methods to evaluate treatment heterogeneity in clinical studies.

Preoperative Inflammatory Markers in Liver Resection for Colorectal Liver Metastases: A National Registry-Based Study.

BACKGROUND: Preoperative inflammatory markers were shown to be associated with prognosis following surgery for hepato-pancreato-biliary cancer. Yet little evidence exists about their role in patients with colorectal liver metastases (CRLM). This study aimed to examine the association between selected preoperative inflammatory markers and outcomes of liver resection for CRLM. METHODS: Data from the Norwegian National Registry for Gastrointestinal Surgery (NORGAST) was used to capture all liver resections performed in Norway within the study period (November 2015-April 2021). Preoperative inflammatory markers were Glasgow prognostic score (GPS), modified Glasgow prognostic score (mGPS) and C-reactive protein to albumin ratio (CAR). The impact of these on postoperative outcomes, as well as on survival were studied. RESULTS: Liver resections for CRLM were performed in 1442 patients. Preoperative GPS ≥ 1 and mGPS ≥ 1 were present in 170 (11.8%) and 147 (10.2%) patients, respectively. Both were associated with severe complications but became non-significant in the multivariable model. GPS, mGPS, CAR were significant predictors for overall survival in the univariable analysis, but only CAR remained such in the multivariable model. When stratified by the type of surgical approach, CAR was a significant predictor for survival after open but not laparoscopic liver resections. CONCLUSIONS: GPS, mGPS and CAR have no impact on severe complications after liver resection for CRLM. CAR outperforms GPS and mGPS in predicting overall survival in these patients, especially following open resections. The prognostic significance of CAR in CRLM should be tested against other clinical and pathology parameters relevant for prognosis.

Current and future diagnostic and treatment strategies for patients with invasive lobular breast cancer.

BACKGROUND: Invasive lobular breast cancer (ILC) is the second most common type of breast cancer after invasive breast cancer of no special type (NST), representing up to 15% of all breast cancers. DESIGN: Latest data on ILC are presented, focusing on diagnosis, molecular make-up according to the European Society for Medical Oncology Scale for Clinical Actionability of molecular Targets (ESCAT) guidelines, treatment in the early and metastatic setting and ILC-focused clinical trials. RESULTS: At the imaging level, magnetic resonance imaging-based and novel positron emission tomography/computed tomography-based techniques can overcome the limitations of currently used imaging techniques for diagnosing ILC. At the pathology level, E-cadherin immunohistochemistry could help improving inter-pathologist agreement. The majority of patients with ILC do not seem to benefit as much from (neo-)adjuvant chemotherapy as patients with NST, although chemotherapy might be required in a subset of high-risk patients. No differences in treatment efficacy are seen for anti-human epidermal growth factor receptor 2 (HER2) therapies in the adjuvant setting and cyclin-dependent kinases 4 and 6 inhibitors in the metastatic setting. The clinical utility of the commercially available prognostic gene expression-based tests is unclear for patients with ILC. Several ESCAT alterations differ in frequency between ILC and NST. Germline BRCA1 and PALB2 alterations are less frequent in patients with ILC, while germline CDH1 (gene coding for E-cadherin) alterations are more frequent in patients with ILC. Somatic HER2 mutations are more frequent in ILC, especially in metastases (15% ILC versus 5% NST). A high tumour mutational burden, relevant for immune checkpoint inhibition, is more frequent in ILC metastases (16%) than in NST metastases (5%). Tumours with somatic inactivating CDH1 mutations may be vulnerable for treatment with ROS1 inhibitors, a concept currently investigated in early and metastatic ILC. CONCLUSION: ILC is a unique malignancy based on its pathological and biological features leading to differences in diagnosis as well as in treatment response, resistance and targets as compared to NST.

Prognosis of pregnancy-associated breast cancer: inferior outcome in patients diagnosed during second and third gestational trimesters and lactation.

PURPOSE: Pregnancy-associated breast cancer, although most commonly defined as breast cancer diagnosed during pregnancy or ≤1 year following delivery, knows a variety of definitions, likely related to the diversity of reported clinicopathological features and prognosis. More insight into the different breast cancer subgroups during pregnancy, time after delivery and the postpartum period is therefore warranted. METHODS: Patients with breast cancer diagnosed during pregnancy or ≤6 months postdelivery were included, and subdivided according to gestational trimester, and postpartum patients according to lactational status. Subgroups were compared to matched non-PABC patients, to investigate the influence of pregnancy and lactation on clinical course and outcome. RESULTS: Overall, 662 PABC patients were included (median age 34 years, median follow-up 6.5 years). PABC patients showed an advanced stage at diagnosis and an inferior 5-years-OS (75.4% vs. 83.2%, p = 0.000) compared to 1392 matched non-PABC patients. In subgroup analysis, first trimester PABC patients showed a significantly lower tumor size and stage as compared to other trimesters. Patients diagnosed during the first trimester and postpartum non-lactating patients had a relatively good OS (81.3% and 77.9%, respectively) versus patients diagnosed during the second and third trimesters and during lactation (OS 60.0%, 64.9% and 65.6%, respectively, p = 0.003). CONCLUSION: In this large (uniquely specified) PABC cohort, an inferior outcome was found for patients diagnosed within the second and third gestational trimesters and during lactation. These findings indicate that PABC is clinically a heterogeneous group of breast cancer patients that should be redefined based on trimester of diagnosis and lactational status.

Limiting systemic endocrine overtreatment in postmenopausal breast cancer patients with an ultralow classification of the 70-gene signature.

PURPOSE: Guidelines recommend endocrine treatment for estrogen receptor-positive (ER+) breast cancers for up to 10 years. Earlier data suggest that the 70-gene signature (MammaPrint) has potential to select patients that have an excellent survival without chemotherapy and limited or no tamoxifen treatment. The aim was to validate the 70-gene signature ultralow-risk classification for endocrine therapy decision making. METHODS: In the IKA trial, postmenopausal patients with non-metastatic breast cancer had been randomized between no or limited adjuvant tamoxifen treatment without receiving chemotherapy. For this secondary analysis, FFPE tumor material was obtained of ER+HER2- patients with 0-3 positive lymph nodes and tested for the 70-gene signature. Distant recurrence-free interval (DRFI) long-term follow-up data were collected. Kaplan-Meier curves were used to estimate DRFI, stratified by lymph node status, for the three predefined 70-gene signature risk groups. RESULTS: A reliable 70-gene signature could be obtained for 135 patients. Of the node-negative and node-positive patients, respectively, 20% and 13% had an ultralow-risk classification. No DRFI events were observed for node-negative patients with an ultralow-risk score in the first 10 years. The 10-year DRFI was 90% and 66% in the low-risk (but not ultralow) and high-risk classified node-negative patients, respectively. CONCLUSION: These survival analyses indicate that the postmenopausal node-negative ER+HER2- patients with an ultralow-risk 70-gene signature score have an excellent 10-year DRFI after surgery with a median of 1 year of endocrine treatment. This is in line with published results of the STO-3-randomized clinical trial and supports the concept that it is possible to reduce the duration of endocrine treatment in selected patients.

Revascularization of human ovarian grafts is equally efficient from both sides of the cortex tissue.

RESEARCH QUESTION: Does revascularization of human ovarian grafts in a mouse model occur with equal efficiency from both sides of the cortex tissue? DESIGN: Twenty-four frozen-thawed ovarian cortex pieces from 12 women were transplanted to immunodeficient mice, for 8 days to analyse graft revascularization using immunohistochemical detection of murine CD31, or for 8 weeks to evaluate follicle density (follicles/mm3). The CD31-positive vessel area and density were quantified using a custom-designed application. Three regions of interest (ROI) were defined in each tissue section: the cortical side, the centre and the medullary side. Vessels were subdivided into three categories according to size: microvessels (<300 µm2), small vessels (300-1000 µm2) and large vessels (>1000-3000 µm2). RESULTS: No significant difference in the mean percentage of the CD31-positive vessel area was found between the three ROI (cortical side: 3.9% ± 0.2%; centre: 3.5% ± 0.2%; medullary side: 4.0% ± 0.3%; P = 0.17), but a significantly lower density of vessels was found in the centre of the human ovarian grafts compared with the cortical and medullary sides (cortical side: 323 ± 14 vessels/mm2; centre: 240 ± 12 vessels/mm2; medullary side: 301 ± 18 vessels/mm2; P < 0.001). Microvessels comprised 89-91% of all vessels in the three ROI. Follicle density in ungrafted cortex pieces was 51.8 ± 17.3 and 14.7 ± 3.7 follicles/mm3 after 8 weeks of xenografting, resulting in a follicle survival rate of 28%. CONCLUSIONS: Host revascularization was established equally efficiently from both sides of transplanted human ovarian cortex, suggesting that transplantation techniques ensuring revascularization from both sides of the ovarian graft could potentially facilitate faster graft revascularization.

Assessment of structural chromosomal instability phenotypes as biomarkers of carboplatin response in triple negative breast cancer: the TNT trial.

BACKGROUND: In the TNT trial of triple negative breast cancer (NCT00532727), germline BRCA1/2 mutations were present in 28% of carboplatin responders. We assessed quantitative measures of structural chromosomal instability (CIN) to identify a wider patient subgroup within TNT with preferential benefit from carboplatin over docetaxel. PATIENTS AND METHODS: Copy number aberrations (CNAs) were established from 135 formalin-fixed paraffin-embedded primary carcinomas using Illumina OmniExpress SNP-arrays. Seven published [allelic imbalanced CNA (AiCNA); allelic balanced CNA (AbCNA); copy number neutral loss of heterozygosity (CnLOH); number of telomeric allelic imbalances (NtAI); BRCA1-like status; percentage of genome altered (PGA); homologous recombination deficiency (HRD) scores] and two novel [Shannon diversity index (SI); high-level amplifications (HLAMP)] CIN-measurements were derived. HLAMP was defined based on the presence of at least one of the top 5% amplified cytobands located on 1q, 8q and 10p. Continuous CIN-measurements were divided into tertiles. All nine CIN-measurements were used to analyse objective response rate (ORR) and progression-free survival (PFS). RESULTS: Patients with tumours without HLAMP had a numerically higher ORR and significantly longer PFS in the carboplatin (C) than in the docetaxel (D) arm [56% (C) versus 29% (D), PHLAMP,quiet = 0.085; PFS 6.1 months (C) versus 4.1 months (D), Pinteraction/HLAMP = 0.047]. In the carboplatin arm, patients with tumours showing intermediate telomeric NtAI and AiCNA had higher ORR [54% (C) versus 20% (D), PNtAI,intermediate = 0.03; 62% (C) versus 33% (D), PAiCNA,intermediate = 0.076]. Patients with high AiCNA and PGA had shorter PFS in the carboplatin arm [3.4 months (high) versus 5.7 months (low/intermediate); and 3.8 months (high) versus 5.6 months (low/intermediate), respectively; Pinteraction/AiCNA = 0.027, Padj.interaction/AiCNA = 0.125 and Pinteraction/PGA = 0.053, Padj.interaction/PGA = 0.176], whilst no difference was observed in the docetaxel arm. CONCLUSIONS: Patients with tumours lacking HLAMP and demonstrating intermediate CIN-measurements formed a subgroup benefitting from carboplatin relative to docetaxel treatment within the TNT trial. This suggests a complex and paradoxical relationship between the extent of genomic instability in primary tumours and treatment response in the metastatic setting.

Pregnancy-associated breast cancer: nationwide Dutch study confirms a discriminatory aggressive histopathologic profile.

PURPOSE: Breast cancer is the most common type of malignancy in pregnant women, occurring approximately once in every 3000 pregnancies. Pregnancy-associated breast cancer (PABC) is commonly defined as breast cancer diagnosed during or within one year after pregnancy, and it accounts for up to 6.9% of all breast cancers in women younger than 45 years old. Whether these cancers arise before or during pregnancy, and whether they are stimulated by the high hormonal environment of pregnancy, is currently unknown. This study assesses the histopathological profile of PABC in a large Dutch population-based cohort. METHODS: We identified 744 patients with PABC (in this cohort defined as breast cancer diagnosed during or within 6 months after pregnancy) diagnosed between 1988 and 2019, in the nationwide Dutch Pathology Registry (PALGA). An age-matched PALGA cohort of unselected breast cancer patients (≤ 45 years), diagnosed between 2013 and 2016, was used as a control. Histopathologic features of both cohorts were compared. RESULTS: The median age of PABC patients was 34.3 years old (range 19-45 years) and most breast cancers were diagnosed during pregnancy (74.2%). As compared to age-matched controls, PABC patients had tumors of higher Bloom-Richardson grade (grade I: 1.5% vs. 12.4%, grade II: 16.9% vs. 31.3%, grade III: 80.3% vs. 39.5%, p < 0.0001). Furthermore, estrogen (ER)- and progesterone (PR)-receptor expression was less frequently reported positive (ER: 38.9% vs. 68.2% and PR: 33.9% vs. 59.0%, p < 0.0001), while a higher percentage of PABC tumors overexpressed HER2 (20.0% vs. 10.0%, p < 0.0001). The most observed intrinsic subtype in PABC was triple-negative breast cancer (38.3% vs. 22.0%, p < 0.0001), whereas hormone-driven cancers were significantly less diagnosed (37.9% vs. 67.3%, p < 0.0001). CONCLUSION: This study, based on a large population-based cohort of 744 PABC Dutch patients, underlines the more aggressive histopathologic profile compared to age-matched breast cancer patients ≤ 45 years. Further in-depth genetic analysis will be performed to unravel the origin of this discriminating phenotype. It definitely calls for timely detection and optimal treatment of this small but delicate subgroup of breast cancer patients.

A real or apparent decrease in glomerular filtration rate in patients using olaparib?

PURPOSE: Olaparib is a poly (ADP-ribose) polymerase (PARP) inhibitor indicated for ovarian and metastatic breast cancer. Increased serum creatinine levels have been observed in patients taking olaparib, but the underlying mechanism is unknown. This study aimed to investigate if patients receiving olaparib have increased creatinine levels during olaparib treatment and whether this actually relates to a declined glomerular filtration rate (GFR). METHODS: We retrospectively identified patients using olaparib at the Netherlands Cancer Institute - Antoni van Leeuwenhoek (NKI-AVL) from 2012 until 2020. Patients with at least one plasma or serum sample available at baseline/off treatment and during olaparib treatment were included. Cystatin C levels were measured, creatinine levels were available and renal function was determined by calculating the estimated glomerular filtration rate (eGFR) using the Creatinine Equation (CKD-EPI 2009) and the Cystatin C Equation (CKD-EPI 2012). RESULTS: In total, 66 patients were included. Olaparib treatment was associated with a 14% increase in median creatinine from 72 (inter quartile range (IQR): 22) µmol/L before/off treatment to 82 (IQR: 20) µmol/L during treatment (p < 0.001) and a 13% decrease in median creatinine-derived eGFR from 86 (IQR: 26) mL/min/1.73 m2 before/off treatment to 75 (IQR: 29) mL/min/1.73 m2 during treatment (p < 0.001). Olaparib treatment had no significant effect on median cystatin C levels (p = 0.520) and the median cystatin C-derived eGFR (p = 0.918). CONCLUSIONS: This study demonstrates that olaparib likely causes inhibition of renal transporters leading to a reversible and dose-dependent increase in creatinine and does not affect GFR, since the median cystatin C-derived eGFR was comparable before/off treatment and during treatment of olaparib. Using the creatinine-derived eGFR can give an underestimation of GFR in patients taking olaparib. Therefore, an alternative renal marker such as cystatin C should be used to accurately calculate eGFR in patients taking olaparib.

Non-pharmacological interventions for stuttering in children six years and younger.

BACKGROUND: Stuttering, or stammering as it is referred to in some countries, affects a child's ability to speak fluently. It is a common communication disorder, affecting 11% of children by four years of age. Stuttering can be characterized by sound, part word or whole word repetitions, sound prolongations, or blocking of sounds or airflow. Moments of stuttering can also be accompanied by non-verbal behaviours, including visible tension in the speaker's face, eye blinks or head nods. Stuttering can also negatively affect behavioural, social and emotional functioning. OBJECTIVES: Primary objective To assess the immediate and long-term effects of non-pharmacological interventions for stuttering on speech outcomes, communication attitudes, quality of life and potential adverse effects in children aged six years and younger. Secondary objective To describe the relationship between intervention effects and participant characteristics (i.e. child age, IQ, severity, sex and time since stuttering onset) at pretest. SEARCH METHODS: We searched CENTRAL, MEDLINE, Embase, PsycINFO, nine other databases and two trial registers on 16 September 2020, and Open Grey on 20 October 2020. There were no limits in regards to language, year of publication or type of publication. We also searched the reference lists of included studies and requested data on unpublished trials from authors of published studies. We handsearched conference proceedings and programmes from relevant conferences. SELECTION CRITERIA: We included randomized controlled trials (RCTs) and quasi-RCTs that assessed non-pharmacological interventions for stuttering in young children aged six years and younger. Eligible comparators were no intervention, wait list or management as usual. DATA COLLECTION AND ANALYSIS: We used standard methodological procedures expected by Cochrane. MAIN RESULTS: We identified four eligible RCTs, all of which compared the Lidcombe Program to a wait-list control group. In total, 151 children aged between two and six years participated in the four included studies. In the Lidcombe Program, the parent and their child visit a speech and language therapist (SLT) in a clinic. One study conducted clinic visits by telephone. In each clinic visit, parents were taught how to conduct treatment at home. Two studies took place in Australia, one in New Zealand and one in Germany. Two studies were conducted for nine months, one for 16 weeks and one for 12 weeks. The frequency of clinic visits and practice sessions at home varied within the programme. One study was partially funded by the Rotary Club, Wiesbaden, Germany; and one was funded by the National Health and Medical Research Council of Australia. One study did not report funding sources and another reported that they did not receive any funding for the trial.  All four studies reported the outcome of stuttering frequency. One study also reported on speech efficiency, defined as articulation rate. No studies reported the other predetermined outcomes of this review, namely stuttering severity; communication attitudes; emotional, cognitive or psychosocial domains; or adverse effects.  The Lidcombe Program resulted in a lower stuttering frequency percentage syllables stuttered (% SS) than a wait-list control group at post-test, 12 weeks, 16 weeks and nine months postrandomization (mean difference (MD) -2.16, 95% confidence interval (CI) -3.48 to -0.84, 4 studies, 151 participants; P = 0.001; very low-certainty evidence).  However, as the Lidcombe Program is designed to take one to two years to complete, none of the participants in these studies had finished the complete intervention programme at any of the data collection points. We assessed stuttering frequency to have a high risk of overall bias due to high risk of bias in at least one domain within three of four included studies, and to have some concern of overall bias in the fourth, due to some concern in at least one domain. We found moderate-certainty evidence from one study showing that the Lidcombe Program may increase speech efficiency in young children. Only one study reported outcomes at long-term follow-up. The long-term effect of intervention could not be summarized, as the results for most of the children in the control group were missing. However, a within-group comparison was performed between the mean % SS at randomization and the mean % SS at the time of extended follow-up, and showed a significant reduction in frequency of stuttering.  AUTHORS' CONCLUSIONS: This systematic review indicates that the Lidcombe Program may result in lower stuttering frequency and higher speech efficiency than a wait-list control group in children aged up to six years at post-test. However, these results should be interpreted with caution due to the very low and moderate certainty of the evidence and the high risk of bias identified in the included studies. Thus, there is a need for further studies from independent researchers, to evaluate the immediate and long-term effects of other non-pharmacological interventions for stuttering compared to no intervention or a wait-list control group.

Exploring Conformational Dynamics of the Extracellular Venus flytrap Domain of the GABAB Receptor: A Path-Metadynamics Study.

γ-Aminobutyric acid (GABA) is the main inhibitory neurotransmitter in the central nervous system (CNS). Dysfunctional GABAergic neurotransmission is associated with numerous neurological and neuropsychiatric disorders. The GABAB receptor (GABAB-R) is a heterodimeric class C G protein-coupled receptor (GPCR) comprised of GABAB1a/b and GABAB2 subunits. The orthosteric binding site for GABA is located in the extracellular Venus flytrap (VFT) domain of the GABAB1a/b. Knowledge about molecular mechanisms and druggable receptor conformations associated with activation is highly important to understand the receptor function and for rational drug design. Currently, the conformational changes of the receptor upon activation are not well described. On the basis of other class C members, the VFT is proposed to fluctuate between an open/inactive and closed/active state and one of these conformations is stabilized upon ligand binding. In the present study, we investigated the dynamics of the GABAB1b-R VFT in the apo form by combining unbiased molecular dynamics with path-metadynamics. Our simulations confirmed the open/inactive and closed/active state as the main conformations adopted by the receptor. Sizeable energy barriers were found between stable minima, suggesting a relatively slow interconversion. Previously undisclosed metastable states were also identified, which might hold potential for future drug discovery efforts.

Reduced hepatic metallothionein expression in first trimester fetuses in response to intrauterine smoking exposure: a consequence of low maternal zinc levels?

STUDY QUESTION: Does maternal smoking in early pregnancy affect metallothionein 1 and 2 (MT1 and MT2) mRNA and protein expression in first trimester placenta or embryonic/fetal liver? SUMMARY ANSWER: In the first trimester, MT protein expression is seen only in liver, where smoking is associated with a significantly reduced expression. WHAT IS KNOWN ALREADY: Zinc homeostasis is altered by smoking. Smoking induces MT in the blood of smokers properly as a result of the cadmium binding capacities of MT. In term placenta MT is present and smoking induces gene and protein expression (MT2 in particular), but the MT presence and response to smoking have never been examined in first trimester placenta or embryonic/fetal tissues. STUDY DESIGN, SIZE, DURATION: Cross sectional study where the presence of MT mRNA and protein was examined at the time of the abortion. The material was collected with informed consent after surgical intervention and frozen immediately. For protein expression analysis, liver tissue originating from smoking exposed n = 10 and unexposed n = 12 pregnancies was used. For mRNA expression analyses, placental tissue originating from smokers n = 19 and non-smokers n = 23 and fetal liver tissue from smoking exposed n = 16 and smoking unexposed pregnancies n = 13, respectively, were used. PARTICIPANTS/MATERIALS, SETTING, METHODS: Tissues were obtained from women who voluntarily and legally chose to terminate their pregnancy between gestational week 6 and 12. Western blot was used to determine the protein expression of MT, and real-time PCR was used to quantify the mRNA expression of MT2A and eight MT1 genes alongside the expression of key placental zinc transporters: zinc transporter protein-1 (ZNT1), Zrt-, Irt-related protein-8 and -14 (ZIP8 and ZIP14). MAIN RESULTS AND THE ROLE OF CHANCE: A significant reduction in the protein expression of MT1/2 in liver tissue (P = 0.023) was found by western blot using antibodies detecting both MT forms. Overall, a similar tendency was observed on the mRNA level although not statistically significant. Protein expression was not present in placenta, but the mRNA regulation suggested a down regulation of MT as well. A suggested mechanism based on the known role of MT in zinc homeostasis could be that the findings reflect reduced levels of easily accessible zinc in the blood of pregnant smokers and hence a reduced MT response in smoking exposed fetal/embryonic tissues. LIMITATIONS AND REASONS FOR CAUTION: Smoking was based on self-reports; however, our previous studies have shown high consistency regarding cotinine residues and smoking status. Passive smoking could interfere but was found mainly among smokers. The number of fetuses was limited, and other factors such as medication and alcohol might affect the findings. Information on alcohol was not consistently obtained, and we cannot exclude that it was more readily obtained from non-users. In the study, alcohol consumption was reported by a limited number (less than 1 out of 5) of women but with more smokers consuming alcohol. However, the alcohol consumption reported was typically limited to one or few times low doses. The interaction between alcohol and smoking is discussed in the paper. Notably we would have liked to measure zinc status to test our hypothesis, but maternal blood samples were not available. WIDER IMPLICATIONS OF THE FINDINGS: Zinc deficiency-in particular severe zinc deficiency-can affect pregnancy outcome and growth. Our findings indicate that zinc homeostasis is also affected in early pregnancy of smokers, and we know from pilot studies that even among women who want to keep their babies, the zinc status is low. Our findings support that zinc supplements should be considered in particular to women who smoke. STUDY FUNDING/COMPETING INTEREST(S): We thank the Department of Biomedicine for providing laboratory facilities and laboratory technicians and the Lundbeck Foundation and Læge Sofus Carl Emil Friis og Hustru Olga Doris Friis Legat for financial support. The authors have no competing interests to declare. TRIAL REGISTRATION NUMBER: N/A.

Variation in use of open and laparoscopic distal pancreatectomy and associated outcome metrics in a universal health care system.

BACKGROUND: Universal health care (UHC) should ensure equal access to and use of surgery, but few studies have explored variation in UHC systems. The objective was to describe practice of distal pancreatectomy in Norway covered exclusively by an UHC. METHODS: Data on all patients undergoing distal pancreatectomy from the Norwegian Patient Register over a 5-year period. Age- and gender-adjusted population-based resection rates (adj. per million/yr) for distal pancreatectomy were analysed across 4 regions and outcomes related to splenic salvage rate, hospital stay, reoperation, readmissions and 90-day mortality risk between regions. Risk is reported as odds ratio (OR) with 95% confidence interval (c.i.). RESULTS: Regional difference exist in terms of absolute numbers, with the majority of procedures done in one region (n = 331; 59.7%). Regional variation persisted for age- and gender-adjusted population-rates, with highest rate at 23.8/million/yr and lowest rate at 13.5/mill/yr (for a 176% relative difference; or an absolute difference of +10.3 resections/million/yr). Overall, a lapDP instead of an open DP was 3.5 times more likely in SouthEast compared to all other regions combined (lapDP rate: 83% vrs 24%, respectively; OR 15.4, 95% c.i. 10.1-23.5; P < 0.001). The splenic salvage rate was lower in SouthEast (19.9%) compared to all other regions (average 26.5%; highest in Central-region at 37.0%; P = 0.010 for trend). Controlled for other factors in multivariate regression, 'region' of surgery remained significantly associated with laparoscopic access. CONCLUSION: Despite a universal health care system, considerable variation exists in resection rates, use of laparoscopy and splenic salvage rates across regions.

Multiple isotope tracers in fur keratin discriminate between mothers and offspring.

RATIONALE: Isoscape origin models for mammals may be impaired by fractionation and routing of isotopes during lactation. Here, we tested if the stable carbon, nitrogen and hydrogen ratios of juvenile bats differ from those of their mothers and if derived isotopic dietary niches and geographical assignments vary accordingly between mothers and juveniles. METHODS: During the post-lactation period, we collected fur of juvenile and female common noctule bats (Nyctalus noctula) from the same maternity roost. Using a combination of elemental analysis and stable isotope ratio mass spectrometry, we measured the hydrogen, carbon and nitrogen isotope ratios in fur keratin. The hydrogen isotope ratios were measured for the non-exchangeable portion of hydrogen in keratin. The derived isotopic niches and isoscape origin models were compared between mothers and juveniles. RESULTS: The fur keratin of juveniles was enriched by 1.6‰ in 15 N and depleted by 2.9‰ in 13 C compared with that of the mothers. In addition, the hydrogen isotope ratios were 13.4‰ lower in the fur keratin of juveniles than in that of mothers. The estimated isotopic niches of nursing females and juveniles were not overlapping and differed in size. Overall, the isoscape origin models projected juveniles as being from a more northern origin than the mothers; yet both models suggested the study site as a likely place of origin. CONCLUSIONS: Our results suggest that isotope ratio data of juvenile bats should not be used for transfer functions in isoscape origin models because of isotopic routing and discrimination during lactation. Not accounting for age effects may increase the inaccuracy of geographical assignments in mammals when based on stable hydrogen isotopes.

A nationwide cohort study of resection rates and short-term outcomes in open and laparoscopic distal pancreatectomy.

BACKGROUND: Distal pancreatectomy (DP) is increasingly done by laparoscopy but data from routine practise are scarce. We describe practise in a national cohort. METHODS: Data from the Norwegian Patient Register of all patients undergoing DP from 2012 to 2016. National resection rates were analysed. Short-term outcomes include length of stay, reoperation, readmissions and 90-day mortality. Risk is reported as odds ratio (OR) with 95% confidence interval (c.i.). RESULTS: Of 554 procedures, 327 (59%) were laparoscopic. Median age was 66 years (iqr 55-72) and 52% were women. Resection rates increased during the period for all DP (from 1.76 to 2.39 per 100.000/yr), and significantly for laparoscopic DP (adjusted R-square 0.858; P = 0.015). Elderly patients had more resection (r2 = 0.11; P = 0.019). Splenectomy (n = 427; 77%) was less likely with laparoscopy (laparoscopy 72% vs open 84%, respectively; OR 0.64, 95% c.i. 0.42-0.97; P = 0.035). Multivisceral resections occurred more often in open DP (5.3% vs 1.2% for laparoscopy, OR 4.51, 1.44-14.2; P = 0.008). Reoperation occurred in 34 (6%), readmission in 109 (20%), and mortality in 8 (1.4%). Hospital stay was shorter for laparoscopic DP. CONCLUSION: Use of DP increases in the population, particularly in the elderly, with use of laparoscopic access and an association with a reduced hospital stay.

The effect of centralization on short term outcomes of pancreatoduodenectomy in a universal health care system.

BACKGROUND: Centralization of pancreatic resections is advocated due to a volume-outcome association. Pancreatic surgery is in Norway currently performed only in five teaching hospitals. The aim was to describe the short-term outcomes after pancreatoduodenectomy (PD) within the current organizational model and to assess for regional disparities. METHODS: All patients who underwent PD in Norway between 2012 and 2016 were identified. Mortality (90 days) and relaparotomy (30 days) were assessed for predictors including demographic data and multi-visceral or vascular resection. Aggregated length-of-stay and national and regional incidences of the procedure were also analysed. RESULTS: A total of 930 patients underwent PD during the study period. In-hospital mortality occurred in 20 patients (2%) and 34 patients (4%) died within 90 days. Male gender, age, multi-visceral resection and relaparotomy were independent predictors of 90-day mortality. Some 131 patients (14%) had a relaparotomy, with male gender and multi-visceral resection as independent predictors. There was no difference between regions in procedure incidence or 90-day mortality. There was a disparity within the regions in the use of vascular resection (p = 0.021). CONCLUSION: The short-term outcomes after PD in Norway are acceptable and the 90-day mortality rate is low. The outcomes may reflect centralization of pancreatic surgery.

Variability and repeatability of noctule bat migration in Central Europe: evidence for partial and differential migration.

Each year, large numbers of bats move across Europe between their summer and winter areas, yet even though many of them are endangered and legally protected, we are unaware about many aspects of their migratory behaviour. Here, taking Nyctalus noctula as a model species, we used stable hydrogen isotopic values in fur ( δ2Hf) as an endogenous marker to shed light on the migratory behaviour of more than 1000 bats from hibernacula across Central Europe. Specifically, we asked the following questions: how flexible is migration in temperate zone bats? Which general migration pattern do noctule bats follow? How repeatable and thus predictable is the migratory behaviour of individuals? Do morphological correlates of migration occur in bats? Our study confirmed that noctule bats engage in partial and female-biased migration across Europe, suggesting the strongest migration pressures for northern populations. Further, we revealed a combination of partial and differential migration patterns with highly variable migration distances which lead to a pronounced mixing of different source populations in hibernacula where mating occurs. Most individuals were consistent in their migration strategy over time, i.e. 86% could be repeatedly assigned to either long-distance or regional origin across years. This is consistent with our finding that the between-individual component explained 84% of the variation in δ2Hf values, suggesting specialized individual migratory behaviours and a strong natal philopatry. We discovered a positive correlation between forearm length and migration distance and support for sex-specific effects of migration on body condition. Our study elucidated migration patterns over large geographical scales, demonstrating that considerable numbers of migratory bats originating from distant populations depend on hibernacula across Central Europe, calling for international conservation management.

An Antiestrogenic Activity Score for tamoxifen and its metabolites is associated with breast cancer outcome.

PURPOSE: Endoxifen concentrations have been associated with breast cancer recurrence in tamoxifen-treated patients. However, tamoxifen itself and other metabolites also show antiestrogenic anti-tumor activity. Therefore, the aim of this study was to develop a comprehensive Antiestrogenic Activity Score (AAS), which accounts for concentration and antiestrogenic activity of tamoxifen and three metabolites. An association between the AAS and recurrence-free survival was investigated and compared to a previously published threshold for endoxifen concentrations of 5.97 ng/mL. PATIENTS AND METHODS: The antiestrogenic activities of tamoxifen, (Z)-endoxifen, (Z)-4-hydroxytamoxifen, and N-desmethyltamoxifen were determined in a cell proliferation assay. The AAS was determined by calculating the sum of each metabolite concentration multiplied by an IC50 ratio, relative to tamoxifen. The AAS was calculated for 1370 patients with estrogen receptor alpha (ERα)-positive breast cancer. An association between AAS and recurrence was investigated using Cox regression and compared with the 5.97 ng/mL endoxifen threshold using concordance indices. RESULTS: An AAS threshold of 1798 was associated with recurrence-free survival, hazard ratio (HR) 0.67 (95% confidence interval (CI) 0.47-0.96), bias corrected after bootstrap HR 0.69 (95% CI 0.48-0.99). The concordance indices for AAS and endoxifen did not significantly differ; however, using the AAS threshold instead of endoxifen led to different dose recommendations for 5.2% of the patients. CONCLUSIONS: Endoxifen concentrations can serve as a proxy for the antiestrogenic effect of tamoxifen and metabolites. However, for the aggregate effect of tamoxifen and three metabolites, defined by an integrative algorithm, a trend towards improving treatment is seen and moreover, is significantly associated with breast cancer recurrence.