Enabling personalized perioperative risk prediction by using a machine-learning model based on preoperative data

Preoperative risk assessment is essential for shared decision-making and adequate perioperative care. Common scores provide limited predictive quality and lack personalized information. The aim of this study was to create an interpretable machine-learning-based model to assess the patient's individual risk of postoperative mortality based on preoperative data to allow analysis of personal risk factors. After ethical approval, a model for prediction of postoperative in-hospital mortality based on preoperative data of 66,846 patients undergoing elective non-cardiac surgery between June 2014 and March 2020 was created with extreme gradient boosting. Model performance and the most relevant parameters were shown using receiver operating characteristic (ROC-) and precision-recall (PR-) curves and importance plots. Individual risks of index patients were presented in waterfall diagrams. The model included 201 features and showed good predictive abilities with an area under receiver operating characteristic (AUROC) curve of 0.95 and an area under precision-recall curve (AUPRC) of 0.109. The feature with the highest information gain was the preoperative order for red packed cell concentrates followed by age and c-reactive protein. Individual risk factors could be identified on patient level. We created a highly accurate and interpretable machine learning model to preoperatively predict the risk of postoperative in-hospital mortality. The algorithm can be used to identify factors susceptible to preoperative optimization measures and to identify risk factors influencing individual patient risk.

How robust are the STRONGER and STIL-STRONGER studies?

In 2020, the Sugammadex vs Neostigmine for Reversal of Neuromuscular Blockade and Postoperative Pulmonary Complications (STRONGER) study provided evidence for the first time that use of sugammadex is associated with fewer postoperative pulmonary complications than use of neostigmine. In a recent publication in the British Journal of Anaesthesia, a secondary analysis of the same data, the Association Between Neuromuscular Blockade Reversal Agent Choice and Postoperative Pulmonary Complications (STIL-STRONGER) study, has produced similar evidence of the advantages of sugammadex over neostigmine in high-risk and older patients undergoing prolonged, elective surgery. Here we consider the implications of the detailed statistical analysis used in these two studies and how its limitations could possibly have enhanced the statistical differences between the two drugs with respect to postoperative pulmonary complications.

PITX2 DNA-Methylation: Predictive versus Prognostic Value for Anthracycline-Based Chemotherapy in Triple-Negative Breast Cancer Patients

Background

PITX2 DNA methylation has been shown to predict outcomes in high-risk breast cancer patients after anthracycline-based chemotherapy. To determine its prognostic versus predictive value, the impact of PITX2 DNA methylation on outcomes was studied in an untreated cohort vs. an anthracycline-treated triple-negative breast cancer (TNBC) cohort.

Material and Methods

The percent DNA methylation ratio (PMR) of paired-like homeodomain transcription factor 2 (PITX2) was determined by a validated methylation-specific real-time PCR test. Patient samples of routinely collected archived formalin-fixed paraffin-embedded (FFPE) tissue and clinical data from 144 TNBC patients of 2 independent cohorts (i.e., 66 untreated patients and 78 patients treated with anthracycline-based chemotherapy) were analyzed.

Results

The risk of 5- and 10-year overall survival (OS) increased continuously with rising PITX2 DNA methylation in the anthracycline-treated population, but it increased only slightly during 10-year follow-up time in the untreated patient population. PITX2 DNA methylation with a PMR cutoff of 2 did not show significance for poor vs. good outcomes (OS) in the untreated patient cohort (HR = 1.55; p = 0.259). In contrast, the PITX2 PMR cutoff of 2 identified patients with poor (PMR >2) vs. good (PMR ≤2) outcomes (OS) with statistical significance in the anthracycline-treated cohort (HR = 3.96; p = 0.011). The results in the subgroup of patients who did receive anthracyclines only (no taxanes) confirmed this finding (HR = 5.71; p = 0.014).

Conclusion

In this hypothesis-generating study PITX2 DNA methylation demonstrated predominantly predictive value in anthracycline treatment in TNBC patients. The risk of poor outcome (OS) correlates with increasing PITX2 DNA methylation.

Polyscore of autonomic parameters for risk stratification of the elderly general population: the Polyscore study

Aims

Present society is constantly ageing and elderly frequently suffer from conditions that are difficult and/or costly to treat if detected late. Effective screening of the elderly is therefore needed so that those requiring detailed clinical work-up are identified early. We present a prospective validation of a screening strategy based on a Polyscore of seven predominantly autonomic, non-invasive risk markers.

Methods and results

Within a population-based survey in Germany (INVADE study), participants aged ≥60 years were enrolled between August 2013 and February 2015. Seven prospectively defined Polyscore components were obtained during 30-min continuous recordings of electrocardiogram, blood pressure, and respiration. Out of 1956 subjects, 168 were excluded due to atrial fibrillation, implanted pacemaker, or unsuitable recordings. All-cause mortality over a median 4-year follow-up was prospectively defined as the primary endpoint. The Polyscore divided the investigated population (n = 1788, median age: 72 years, females: 58%) into three predefined groups with low (n = 1405, 78.6%), intermediate (n = 326, 18.2%), and high risk (n = 57, 3.2%). During the follow-up, 82 (4.6%) participants died. Mortality in the Polyscore-defined risk groups was 3.4%, 7.4%, and 17.5%, respectively (P < 0.0001). The Polyscore-based mortality prediction was independent of Framingham score, diabetes, chronic kidney disease, and major stroke and/or myocardial infarction history. It was particularly effective in those aged <75 years (n = 1145).

Conclusion

The Polyscore-based mortality risk assessment from short-term non-invasive recordings is effective in the elderly general population, especially those aged 60–74 years. Implementation of a comprehensive Polyscore screening of this age group is proposed to advance preventive medical care.

Prognostic and predictive value of PD-L1 expression and tumour infiltrating lymphocytes (TiLs) in locally advanced NSCLC treated with simultaneous radiochemotherapy in the randomized, multicenter, phase III German Intergroup lung Trial (GILT)

OBJECTIVES

Immune checkpoint inhibition after radiochemotherapy (RTCT) has become a new standard of care for locally advanced non-small cell lung cancer with programmed death-ligand 1 (PD-L1) expression. However, little is known about the prognostic role of immune response markers in this setting. We analysed PD-L1 expression and tumour infiltrating lymphocytes (TiLs) in tumour biopsies from the multicenter German Intergroup Lung Trial (GILT), which previously randomised patients with stage III NSCLC to RTCT with or without consolidation chemotherapy.

MATERIALS AND METHODS

We retrospectively analyzed tumour biopsies from patients treated in the GILT trial. PD-L1 expression was analysed using the Ventana SP263 assay and TiL score (low, intermediate, high) and pattern (excluded, inflamed, desert) were assessed. The primary endpoint of the biomarker analysis was PFS in patients with PD-L1 ≥ 1% vs. PD-L1 < 1% NSCLC. Secondary endpoints explored the prognostic relevance of additional PD-L1 expression levels and TiL score and pattern.

RESULTS

Biopsies were available from 92 patients treated with RTCT. Patients with available tumor tissue did not differ significantly from the whole study population. PD-L1 scores from 78 samples were available for analysis. There was no difference in PFS in the PD-L1 < 1% vs. PD-L1 ≥ 1% subgroups. TiL score was available in 66 patients. Patients with high TiL score showed favourable overall survival compared to the low TiL subgroup. This trend was most pronounced in those patients treated with consolidative chemotherapy.

CONCLUSION

In this analysis, PD-L1 expression did not correlate with PFS following RTCT. However, patients with TiLs > 10% were found to have longer overall survival, especially for those patients treated with consolidation chemotherapy after the end of RTCT. Further analyses to explore the prognostic and predictive relevance of TiLs in the context of consolidative checkpoint inhibition with durvalumab are required.

SARS-CoV-2 serology increases diagnostic accuracy in CT-suspected, PCR-negative COVID-19 patients during pandemic

Background

In the absence of PCR detection of SARS-CoV-2 RNA, accurate diagnosis of COVID-19 is challenging. Low-dose computed tomography (CT) detects pulmonary infiltrates with high sensitivity, but findings may be non-specific. This study assesses the diagnostic value of SARS-CoV-2 serology for patients with distinct CT features but negative PCR.

Methods

IgM/IgG chemiluminescent immunoassay was performed for 107 patients with confirmed (group A: PCR + ; CT ±) and 46 patients with suspected (group B: repetitive PCR-; CT +) COVID-19, admitted to a German university hospital during the pandemic’s first wave. A standardized, in-house CT classification of radiological signs of a viral pneumonia was used to assess the probability of COVID-19.

Results

Seroconversion rates (SR) determined on day 5, 10, 15, 20 and 25 after symptom onset (SO) were 8%, 25%, 65%, 76% and 91% for group A, and 0%, 10%, 19%, 37% and 46% for group B, respectively; (p < 0.01). Compared to hospitalized patients with a non-complicated course (non-ICU patients), seroconversion tended to occur at lower frequency and delayed in patients on intensive care units. SR of patients with CT findings classified as high certainty for COVID-19 were 8%, 22%, 68%, 79% and 93% in group A, compared with 0%, 15%, 28%, 50% and 50% in group B (p < 0.01). SARS-CoV-2 serology established a definite diagnosis in 12/46 group B patients. In 88% (8/9) of patients with negative serology > 14 days after symptom onset (group B), clinico-radiological consensus reassessment revealed probable diagnoses other than COVID-19. Sensitivity of SARS-CoV-2 serology was superior to PCR > 17d after symptom onset.

Conclusions

Approximately one-third of patients with distinct COVID-19 CT findings are tested negative for SARS-CoV-2 RNA by PCR rendering correct diagnosis difficult. Implementation of SARS-CoV-2 serology testing alongside current CT/PCR-based diagnostic algorithms improves discrimination between COVID-19-related and non-related pulmonary infiltrates in PCR negative patients. However, sensitivity of SARS-CoV-2 serology strongly depends on the time of testing and becomes superior to PCR after the 2^nd week following symptom onset.

Microbiota alteration at different stages in gastric lesion progression: a population-based study in Linqu, China

In addition to Helicobacter pylori (H.pylori), gastric microbiota may be involved in carcinogenesis process. However, the longitudinal study to assess changes in the gastric microbiota associated with the development of gastric carcinogenesis is still limited. The aim of this study is to explore dynamic microbial alterations in gastric cancer (GC) development based on a 4-year endoscopic follow-up cohort in Linqu County, China. Microbial alterations were investigated by deep sequencing of the microbial 16S ribosomal RNA gene in 179 subjects with various gastric lesions, and validated in paired gastric biopsies prospectively collected before and after lesion progression and in non-progression controls. Significant differences were found in microbial diversity and community structure across various gastric lesions, with 62 candidate differential taxa between at least two lesion groups. Further validations identified Helicobacter, Bacillus, Capnocytophaga and Prevotella to be associated with lesion progression-to-dysplasia (DYS)/GC (all P < 0.05), especially for subjects progressing from intestinal metaplasia (IM) to DYS/GC. The combination of the four genera in a microbial dysbiosis index showed a significant difference after lesion progression-to-DYS/GC compared to controls (P = 0.027). The panel including the four genera identified subjects after progression-to-DYS/GC with an area under the receiver-operating curve (AUC) of 0.941. Predictive significance was found before lesion progression-to-DYS/GC with an AUC = 0.776 and an even better AUC (0.927) for subjects progressing from IM to DYS/GC. Microbiota may play different roles at different stages in gastric carcinogenesis. A panel of bacterial genera associated with gastric lesions may help to assess gastric microbial dysbiosis and show potential predictive values for lesion progression. Our findings provide new clues for the microbial mechanism of H.pylori-associated carcinogenesis.

Effect of Helicobacter pylori on gastrointestinal microbiota: a population-based study in Linqu, a high-risk area of gastric cancer

OBJECTIVE

Gastrointestinal microbiota may be involved in Helicobacter pylori-associated gastric cancer development. The aim of this study was to explore the possible microbial mechanisms in gastric carcinogenesis and potential dysbiosis arising from H. pylori infection.

DESIGN

Deep sequencing of the microbial 16S ribosomal RNA gene was used to investigate alterations in paired gastric biopsies and stool samples in 58 subjects with successful and 57 subjects with failed anti-H. pylori treatment, relative to 49 H. pylori negative subjects.

RESULTS

In H. pylori positive subjects, richness and Shannon indexes increased significantly (both p<0.001) after successful eradication and showed no difference to those of negative subjects (p=0.493 for richness and p=0.420 for Shannon index). Differential taxa analysis identified 18 significantly altered gastric genera after eradication. The combination of these genera into a Microbial Dysbiosis Index revealed that the dysbiotic microbiota in H. pylori positive mucosa was associated with advanced gastric lesions (chronic atrophic gastritis and intestinal metaplasia/dysplasia) and could be reversed by eradication. Strong coexcluding interactions between Helicobacter and Fusobacterium, Neisseria, Prevotella, Veillonella, Rothia were found only in advanced gastric lesion patients, and were absent in normal/superficial gastritis group. Changes in faecal microbiota included increased Bifidobacterium after successful H. pylori eradication and more upregulated drug-resistant functional orthologs after failed treatment.

CONCLUSION

H. pylori infection contributes significantly to gastric microbial dysbiosis that may be involved in carcinogenesis. Successful H. pylori eradication potentially restores gastric microbiota to a similar status as found in uninfected individuals, and shows beneficial effects on gut microbiota.

Microbiota-associated risk factors for C. difficile acquisition in hospitalized patients: A prospective, multicentric study

BACKGROUND

Asymptomatic C. difficile colonization is believed to predispose to subsequent C. difficile infection (CDI). While emerging insights into the role of the commensal microbiota in mediating colonization resistance against C. difficile have associated CDI with specific microbial components, corresponding prospectively collected data on colonization with C. difficile are largely unavailable.

METHODS

C. difficile status was assessed by GDH EIA and real-time PCR targeting the toxin A (tcdA) and B (tcdB) genes. 16S V3 and V4 gene sequencing results from fecal samples of patients tested positive for C. difficile were analyzed by assessing alpha and beta diversity, LefSe, and the Piphillin functional inference approach to estimate functional capacity.

RESULTS

1506 patients were recruited into a prospective observational study (DRKS00005335) upon admission into one of five academic hospitals. 936 of them provided fecal samples on admission and at discharge and were thus available for longitudinal analysis. Upon hospital admission, 5.5% (83/1506) and 3.7% (56/1506) of patients were colonized with toxigenic (TCD) and non-toxigenic C. difficile (NTCD), respectively. During hospitalization, 1.7% (16/936) acquired TCD. Risk factors for acquisition of TCD included pre-existing lung diseases, lower GI endoscopy and antibiotics. Species protecting against hospital-related C. difficile acquisition included Gemmiger spp., Odoribacter splanchnicus, Ruminococcus bromii and other Ruminococcus spp.. Metagenomic pathway analysis identified steroid biosynthesis as the most underrepresented metabolic pathway in patients who later acquire C. difficile colonization.

CONCLUSIONS

Gemmiger spp., Odoribacter splanchnicus, Ruminococcus bromii and other Ruminococci were associated with a decreased risk of C. difficile acquisition.

Fixed or adjustable sling in the treatment of male stress urinary incontinence: results from a large cohort study

Background

Fixed and adjustable male slings for the treatment of male urinary stress incontinence became increasingly popular during the last decade. Although fixed slings are recommended for the treatment of mild to moderate stress urinary incontinence, there is still a lack of evidence regarding the precise indication for an adjustable male sling. Furthermore, there is still no evidence that one type of male sling is superior to another. However, both, adjustable and fixed slings, are commonly utilized in daily clinical practice. This current investigation aims to evaluate the differences between fixed and adjustable male slings regarding indications, complication rates and functional outcome in the treatment of male stress urinary incontinence in current clinical practice.

Methods

A total of 294 patients with a fixed and 176 patients with an adjustable male sling were evaluated in a multicenter single arm cohort trial. Data collection was performed retrospectively according the medical record. Functional outcome was prospectively analyzed by standardized, validated questionnaires. Descriptive statistics was performed to present patient characteristics, complication rates and functional outcome. A chi2-test for categorical and independent t-test for continuous variables was performed to identify heterogeneity between the groups and to correlate preoperative characteristics with the outcome. A P value <0.05 was considered statistically significant.

Results

Patients with higher degree of urinary incontinence (P<0.001) and risk factors such as history of pelvic irradiation (P<0.001) or prior surgery for urethral stricture (P=0.032) were more likely to receive an adjustable MS. Complication rates were comparable except for infection (P=0.009, 0 vs. 2.3%) and pain (P=0.001, 1.7% vs. 11.3%) which occurred more frequently in adjustable slings. Functional outcome according validated questionnaires demonstrated no differences between fixed and adjustable male slings.

Conclusions

Adjustable male slings are more frequently utilized in patients with higher degree of incontinence and risk factors compared to fixed slings. No differences could be identified between functional outcome which may imply an advantage for adjustability. However, pain and infection rates were significantly higher in adjustable MS and should be considered in the decision process for sling type.

Abstract P3-08-65: PITX2 DNA methylation: A prognostic/predictive biomarker for anthracycline-based chemotherapy

Background: Published data on the basis of a research-use-only PITX2 methylation assay using fresh-frozen tissue showed that the PITX2 DNA methylation may be a predictive marker for response to (neo) adjuvant anthracycline-based chemotherapy in breast cancer patients, including high-risk lymph node positive, estrogen receptor-positive, HER2-negative breast cancer and triple-negative breast cancer (TNBC). A retrospective study showed that high-risk ER-positive patients with a high PITX2 methylation ratio (PMR&gt;12) had a poor outcome after anthracycline-based chemotherapy [HR 2,28; 95%-Cl 1,49 - 3,49; p&lt;0.001, median DFS 71 months] compared to patients with low PITX2 methylation ratios [PMR≤12, median DFS 105 months]. Nevertheless, the question regarding the prognostic versus predictive value of PITX2 methylation for anthracycline therapy remained unanswered so far. Within an exploratory study using archived tissue specimen, this question was addressed by comparing the impact of PITX2 methylation on outcome in an untreated versus treated TNBC population. Methods: Patient samples and clinical data from 144 TNBC patients of 2 cohorts were analyzed: 1) 66 untreated patients from the Karolinska Institute in Sweden (primary diagnosis 1971-1976) and 2) 78 patients treated with anthracycline-based chemotherapy from the Comprehensive Cancer Center TUM in Germany (primary diagnosis 1996 to 2014). The main eligibility criteria were as follows: ER-negative, PR-negative, HER2-negative breast cancer (TNBC); no endocrine therapy; untreated collective: no further therapy besides surgery and radiation therapy; treated collective: surgery followed by anthracycline based chemotherapy. Samples were assessed for PITX2 methylation using a CE marked PITX2 RGQ PCR Test. The study was designed to determine the PITX2 PMR cut-off value in the untreated population (n=66, prognostic value) and to subsequently determine if this cut-off provides statistical significance in the treated population (n=78, prognostic & predictive value) as well. If no statistically significant cut-off value can be determined in the untreated population, cut-off determination was performed in the treated population and the cut-off was applied in the untreated population. The primary clinical endpoint for all cut-offs was 10-years DFS, secondary clinical endpoints were DFS censored at 5-years and OS censored at 5- and 10-years. Results: The untreated TNBC study population demonstrated a higher event rate at 10-years DFS/OS compared to the anthracycline-treated population [36 DFS/28 OS events vs 28 DFS/14 OS events]. Anthracycline treatment improved significantly overall survival [HR=0.42; p=0.008]. Risk recurrence increased continuously over 5 year and 10 years DFS/OS with increasing PITX2 DNA methylation in the anthracycline-treated population but not in the untreated patients over 5 years DFS/OS and only marginally over 10 years DFS/OS. PITX2 methylation identifies at the cut-off of PMR 2 a patient population with poor vs good overall survival with statistical significance [HR=3.96, p=0.011] in the treated patient cohort but did not identify patients with poor vs good outcome in the untreated patient cohort [HR=1.55, p=0.259].

Summary: In this hypothesis generating study DNA-methylation of PITX2 identifies with high statistical significance anthracycline-treated patients with poor vs good survival. Recurrence risk increases with increasing PITX2 DNA-methylation. PITX2 DNA-methylation shows no prognostic, but significant predictive value for anthracycline treatment in TNBC patients in this study. To confirm conclusively the predictive value of PITX2 DNA-methylation, the results warrant a confirmatory study with tumor specimens from a prospective trial of anthracycline-treated patients vs. anthracycline-free treated patients.

Citation Format: Marion Kiechle, Gabriele Schricker, Rudolf Napieralski, Michaela Aubele, Gert Auer, Kurt Ulm, Jonathan Perkins, Stefan Paepke, Moritz Hamann, Olaf G. Wilhelm. PITX2 DNA methylation: A prognostic/predictive biomarker for anthracycline-based chemotherapy [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr P3-08-65.

Confidence interval estimation for the changepoint of treatment stratification in the presence of a qualitative covariate-treatment interaction

The goal in stratified medicine is to administer the "best" treatment to a patient. Not all patients might benefit from the same treatment; the choice of best treatment can depend on certain patient characteristics. In this article, it is assumed that a time-to-event outcome is considered as a patient-relevant outcome and a qualitative interaction between a continuous covariate and treatment exists, ie, that patients with different values of one specific covariate should be treated differently. We suggest and investigate different methods for confidence interval estimation for the covariate value, where the treatment recommendation should be changed based on data collected in a randomized clinical trial. An adaptation of Fieller's theorem, the delta method, and different bootstrap approaches (normal, percentile-based, wild bootstrap) are investigated and compared in a simulation study. Extensions to multivariable problems are presented and evaluated. We observed appropriate confidence interval coverage following Fieller's theorem irrespective of sample size but at the cost of very wide or even infinite confidence intervals. The delta method and the wild bootstrap approach provided the smallest intervals but inadequate coverage for small to moderate event numbers, also depending on the location of the true changepoint. For the percentile-based bootstrap, wide intervals were observed, and it was slightly conservative regarding coverage, whereas the normal bootstrap did not provide acceptable results for many scenarios. The described methods were also applied to data from a randomized clinical trial comparing two treatments for patients with symptomatic, severe carotid artery stenosis, considering patient's age as predictive marker.

A Simulation Study Comparing Different Statistical Approaches for the Identification of Predictive Biomarkers

Identification of relevant biomarkers that are associated with a treatment effect is one requirement for adequate treatment stratification and consequently to improve health care by administering the best available treatment to an individual patient. Various statistical approaches were proposed that allow assessing the interaction between a continuous covariate and treatment. Nevertheless, categorization of a continuous covariate, e.g., by splitting the data at the observed median value, appears to be very prevalent in practice. In this article, we present a simulation study considering data as observed in a randomized clinical trial with a time-to-event outcome performed to compare properties of such approaches, namely, Cox regression with linear interaction, Multivariable Fractional Polynomials for Interaction (MFPI), Local Partial-Likelihood Bootstrap (LPLB), and the Subpopulation Treatment Effect Pattern Plot (STEPP) method, and of strategies based on categorization of continuous covariates (splitting the covariate at the median, splitting at quartiles, and using an "optimal" split by maximizing a corresponding test statistic). In different scenarios with no interactions, linear interactions or nonlinear interactions, type I error probability and the power for detection of a true covariate-treatment interaction were estimated. The Cox regression approach was more efficient than the other methods for scenarios with monotonous interactions, especially when the number of observed events was small to moderate. When patterns of the biomarker-treatment interaction effect were more complex, MFPI and LPLB performed well compared to the other approaches. Categorization of data generally led to a loss of power, but for very complex patterns, splitting the data into multiple categories might help to explore the nature of the interaction effect. Consequently, we recommend application of statistical methods developed for assessment of interactions between continuous biomarkers and treatment instead of arbitrary or data-driven categorization of continuous covariates.

Abstract P1-13-01: Final results of the ASG1-3 study, a randomized phase III study comparing a standard dose chemotherapy with epirubicin/cyclophosphamide and paclitaxel with a dose dense regimen with epirubicin and paclitaxel

Background

Dose dense chemotherapy (DDT) has shown improvements of disease-free survival (DFS) and overall survival for primary breast cancer patients with a high risk of relapse. There are much less data about the effect of DDT in patients with intermediate risk of recurrence (1-3 positive axillary lymph nodes). Aim of this prospectively randomized trial was to investigate the superiority of a DDT schedule over a standard chemotherapy (ST) in primary breast cancer patients with 1-3 positive axillary lymph nodes.

Methods

The ASG1-3 study is a prospectively randomized, open label phase III study of the Adjuvant Study Group of the NOGGO association. Patients were eligible for the trial, if they had a primary invasive breast cancer (pT1-3) with 1-3 positive axillary lymph nodes and no evidence of distant metastases. Patients were randomized to an adjuvant therapy with either 4 cycles epirubicin (90mg/m2 body surface area, BSA) and cyclophosphamide (600mg/m2 BSA) q3w, followed by 4 cycles of paclitaxel (175mg/m2 BSA) referred to as ST or to a therapy with 4 cycles of epicubicin (120 mg/m2 BSA) q2w and primary G-CSF support followed by 4 cycles of paclitaxel (175mg/m2 BSA) q2w and primary G-CSF support referred to as DDT. Trastuzumab was not given in this study. The study was designed to show an increase of 70% DFS (ST) to 80% DFS (DDT) 5 years after randomization. Comparisons were conducted using Kaplan Meier estimates, log rank tests and Cox regression analyses. In an exploratory way, subgroup analyses were performed for HER2, hormone receptor status and grading using Cox regression models with interaction terms.

Results

A total of 936 patients were eligible for survival analysis, of which 465 were randomized to ST and 471 to DDT from 2001 to 2004. Patient characteristics were mainly well balanced, with patients being 52.5/52.1 years old, 71.9/78.1% being hormone receptor positive, 24.4/24.6% being HER2 positive and 38.6/38.8% having a tumor grade of 3 in the ST arm and DDT arm respectively. 53 events occurred after ST and 46 after DDT. Adjusted hazard ratio (HR) was 0.87 (95%CI: 0.57-1.35; p=0.54). 5 year DFS rates were 85% (ST) vs. 87% (DDT). Hematological toxicities were the most common grade 3 or 4 adverse events. Grade 3/4 neutropenia occurred in 57.2 vs. 28.0%, grade 3/4 anemia in 15.3% vs. 17.1% and grade 3 /4 pain symptoms were seen in 13.2 vs. 12.4% of the patients in the ST arm vs. DDT arm respectively. Other grade 3/4 toxicities were less frequent than 10%. Subgroup analysis showed a significant interaction (p&lt;0.001) between HER2 status and randomization arm with regard to DFS. In HER2 negative patients the HR was 1.53 (95%CI: 0.91-2.59), whereas in HER2 positive patients the HR was 0.22 (95%CI: 0.09-0.55). Patients with HER2 positive disease and DDT had a similar prognosis like HER2 negative patients.

Conclusion

In the overall population a statistically significant improvement of DFS could not be shown for the DDT arm. In patients with HER2 positive breast cancer DDT chemotherapy improved the disease-free survival to a prognosis which was similar to patients with HER2 negative disease.

Citation Format: Fasching PA, Eggemann H, Krocker J, Häberle L, Volz B, Kleine-Tebbe A, Blohmer J-U, Kittel K, Hufnagel M, Janni W, Emons G, Simon E, Köhler U, Thomssen C, Kohls A, Beckmann MW, Hielscher C, Krabisch P, Zeiser T, Brodkorb T, Baier F, Nabieva N, Kellner S, Untch M, Stadie S, Budner M, Breitbach G-P, Keller M, Stickeler E, Kühn T, Tolkmitt M, Belau AK, Schmidt M, Ulm K, Kümmel S. Final results of the ASG1-3 study, a randomized phase III study comparing a standard dose chemotherapy with epirubicin/cyclophosphamide and paclitaxel with a dose dense regimen with epirubicin and paclitaxel [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P1-13-01.

Effects of a lifestyle intervention during pregnancy to prevent excessive gestational weight gain in routine care - the cluster-randomised GeliS trial

BACKGROUND

Excessive gestational weight gain (GWG) leads to obstetric complications, maternal postpartum weight retention and an increased risk of offspring obesity. The GeliS study examines the effect of a lifestyle intervention during pregnancy on the proportion of women with excessive GWG and pregnancy and obstetric complications, as well as the long-term risk of maternal and infant obesity.

METHODS

The GeliS study is a cluster-randomised multicentre controlled trial including 2286 women with a pre-pregnancy BMI between 18.5 and 40.0 kg/m² recruited from gynaecological and midwifery practices prior to the end of the 12^th week of gestation in five Bavarian regions. In the intervention regions, four lifestyle counselling sessions covering a balanced healthy diet, regular physical activity and self-monitoring of weight gain were performed by trained healthcare providers alongside routine pre- and postnatal practice visits. In the control regions, leaflets with general recommendations for a healthy lifestyle during pregnancy were provided.

RESULTS

The intervention did not result in a significant reduction of women showing excessive GWG (adjusted OR 0.95, 95% CI 0.66-1.38, p = 0.789), with 45.1% and 45.7% of women in the intervention and control groups, respectively, gaining weight above the Institute of Medicine recommendations. Gestational diabetes mellitus was diagnosed in 10.8% and 11.1% of women in the intervention and control groups, respectively (p = 0.622). Mean birth weight and length were slightly lower in the intervention group (3313 ± 536 g vs. 3363 ± 498 g, p = 0.020; 51.1 ± 2.7 cm vs. 51.6 ± 2.5 cm, p = 0.001).

CONCLUSION

In the setting of routine prenatal care, lifestyle advice given by trained healthcare providers was not successful in limiting GWG and pregnancy complications. Nevertheless, the potential long-term effects of the intervention remain to be assessed.

TRIAL REGISTRATION

NCT01958307 , ClinicalTrials.gov, retrospectively registered October 9, 2013.

A simulation study on estimating biomarker–treatment interaction effects in randomized trials with prognostic variables

Background

To individualize treatment decisions based on patient characteristics, identification of an interaction between a biomarker and treatment is necessary. Often such potential interactions are analysed using data from randomized clinical trials intended for comparison of two treatments. Tests of interactions are often lacking statistical power and we investigated if and how a consideration of further prognostic variables can improve power and decrease the bias of estimated biomarker–treatment interactions in randomized clinical trials with time-to-event outcomes.

Methods

A simulation study was performed to assess how prognostic factors affect the estimate of the biomarker–treatment interaction for a time-to-event outcome, when different approaches, like ignoring other prognostic factors, including all available covariates or using variable selection strategies, are applied. Different scenarios regarding the proportion of censored observations, the correlation structure between the covariate of interest and further potential prognostic variables, and the strength of the interaction were considered.

Results

The simulation study revealed that in a regression model for estimating a biomarker–treatment interaction, the probability of detecting a biomarker–treatment interaction can be increased by including prognostic variables that are associated with the outcome, and that the interaction estimate is biased when relevant prognostic variables are not considered. However, the probability of a false-positive finding increases if too many potential predictors are included or if variable selection is performed inadequately.

Conclusions

We recommend undertaking an adequate literature search before data analysis to derive information about potential prognostic variables and to gain power for detecting true interaction effects and pre-specifying analyses to avoid selective reporting and increased false-positive rates.

Electronic supplementary material

The online version of this article (doi:10.1186/s13063-018-2491-0) contains supplementary material, which is available to authorized users.

Clinical performance of an analytically validated assay in comparison to microarray technology to assess PITX2 DNA-methylation in breast cancer

Significant evidence has accumulated that DNA-methylation of the paired-like homeodomain transcription factor 2 (PITX2) gene can serve as a prognostic and predictive biomarker in breast cancer. PITX2 DNA-methylation data have been obtained so far from microarray and polymerase chain reaction (PCR)-based research tests. The availability of an analytically validated in vitro methylation-specific real-time PCR assay format (therascreen PITX2 RGQ PCR assay) intended for the determination of the percent methylation ratio (PMR) in the (PITX2) promoter 2 prompted us to investigate whether the clinical performance of these different assay systems generate comparable clinical outcome data. Mathematically converted microarray data of a previous breast cancer study (n = 204) into PMR values leads to a PITX2 cut-off value at PMR 14.73. Recalculation of the data to experimentally equivalent PMRs with the PCR PITX2 assay leads to a cut-off value at PMR 12 with the highest statistical significance. This cut-off predicts outcome of high-risk breast cancer patients to adjuvant anthracycline-based chemotherapy (n = 204; Hazard Ratio 2.48; p < 0.001) comparable to microarray generated results (n = 204; Hazard ratio 2.32; p < 0.0001). The therascreen PITX2 RGQ PCR assay is an analytically validated test with high reliability and robustness and predicts outcome of high-risk breast cancer patients to anthracycline-based chemotherapy.

Clinical Validation of PITX2 DNA Methylation to Predict Outcome in High-Risk Breast Cancer Patients Treated with Anthracycline-Based Chemotherapy

Background: Breast cancer patients at high risk for recurrence are treated with anthracycline-based chemotherapy, but not all patients do equally benefit from such a regimen. To further improve therapy decision-making, biomarkers predicting outcome are of high unmet medical need. Methods: The percent DNA methylation ratio (PMR) of the promoter gene coding for the Paired-like homeodomain transcription factor 2 (PITX2) was determined by a validated methylation-specific real-time polymerase chain reaction (PCR) test. The multicenter study was conducted in routinely collected archived formalin-fixed paraffin-embedded (FFPE) tissue from 205 lymph node-positive breast cancer patients treated with adjuvant anthracycline-based chemotherapy. Results: The cut-off for the PITX2 methylation status (PMR = 12) was confirmed in a randomly selected cohort (n = 60) and validated (n = 145) prospectively with disease-free survival (DFS) at the 10-year follow-up. DFS was significantly different between the PMR ≤ 12 versus the PMR > 12 group with a hazard ratio (HR) of 2.74 (p < 0.001) in the validation cohort and also for the patient subgroup treated additionally with endocrine therapy (HR 2.47; p = 0.001). Conclusions: Early-stage lymph node-positive breast cancer patients with low PITX2 methylation do benefit from adjuvant anthracycline-based chemotherapy. Patients with a high PITX2 DNA methylation ratio, approximately 30%, show poor outcome and should thus be considered for alternative chemotherapy regimens.

Post-anaesthesia pulmonary complications after use of muscle relaxants (POPULAR): a multicentre, prospective observational study

BACKGROUND

Results from retrospective studies suggest that use of neuromuscular blocking agents during general anaesthesia might be linked to postoperative pulmonary complications. We therefore aimed to assess whether the use of neuromuscular blocking agents is associated with postoperative pulmonary complications.

METHODS

We did a multicentre, prospective observational cohort study. Patients were recruited from 211 hospitals in 28 European countries. We included patients (aged ≥18 years) who received general anaesthesia for any in-hospital procedure except cardiac surgery. Patient characteristics, surgical and anaesthetic details, and chart review at discharge were prospectively collected over 2 weeks. Additionally, each patient underwent postoperative physical examination within 3 days of surgery to check for adverse pulmonary events. The study outcome was the incidence of postoperative pulmonary complications from the end of surgery up to postoperative day 28. Logistic regression analyses were adjusted for surgical factors and patients' preoperative physical status, providing adjusted odds ratios (OR_adj) and adjusted absolute risk reduction (ARR_adj). This study is registered with ClinicalTrials.gov, number NCT01865513.

FINDINGS

Between June 16, 2014, and April 29, 2015, data from 22 803 patients were collected. The use of neuromuscular blocking agents was associated with an increased incidence of postoperative pulmonary complications in patients who had undergone general anaesthesia (1658 [7·6%] of 21 694); OR_adj 1·86, 95% CI 1·53-2·26; ARR_adj -4·4%, 95% CI -5·5 to -3·2). Only 2·3% of high-risk surgical patients and those with adverse respiratory profiles were anaesthetised without neuromuscular blocking agents. The use of neuromuscular monitoring (OR_adj 1·31, 95% CI 1·15-1·49; ARR_adj -2·6%, 95% CI -3·9 to -1·4) and the administration of reversal agents (1·23, 1·07-1·41; -1·9%, -3·2 to -0·7) were not associated with a decreased risk of postoperative pulmonary complications. Neither the choice of sugammadex instead of neostigmine for reversal (OR_adj 1·03, 95% CI 0·85-1·25; ARR_adj -0·3%, 95% CI -2·4 to 1·5) nor extubation at a train-of-four ratio of 0·9 or more (1·03, 0·82-1·31; -0·4%, -3·5 to 2·2) was associated with better pulmonary outcomes.

INTERPRETATION

We showed that the use of neuromuscular blocking drugs in general anaesthesia is associated with an increased risk of postoperative pulmonary complications. Anaesthetists must balance the potential benefits of neuromuscular blockade against the increased risk of postoperative pulmonary complications.

FUNDING

European Society of Anaesthesiology.

Ice water test in multiple sclerosis: A pilot trial

OBJECTIVES

To investigate the significance of the ice water test in patients with multiple sclerosis and to evaluate a novel ice water test nomogram in a large patient cohort.

METHODS

A total of 201 ice water tests of patients with multiple sclerosis were retrospectively evaluated. Incontinence episodes in 24 h and sex were correlated with the ice water test. Furthermore, an ice water test nomogram was developed in order to categorize the detrusor overactivity in severity degrees. Descriptive statistics were carried out for population characteristics. Correlations of categorical variables were calculated by the χ² -test. The independent t-test was carried out for correlations of continuous variables. Furthermore, the data were evaluated in the novel ice water test nomogram.

RESULTS

The patient population consisted of 141 (70.1%) women and 60 (39.9%) men. A clinically positive ice water test (maximum detrusor pressure >15 cmH₂ O) was identified in 75 patients (37.3%). Significantly more men presented a clinically positive ice water test (P = 0.006). In 16.5%, the ice water test unmasked an involuntary detrusor contraction, although routine cystometry did not show any detrusor overactivity. The ice water test nomogram could be successfully applied. The incontinence episodes and maximum detrusor pressure correlated positively with a higher categorization in the nomogram. Therapeutic interventions and follow-up controls could be successfully illustrated by the nomogram.

CONCLUSIONS

The ice water test is a simple tool for unmasking non-identified detrusor overactivity in neurogenic bladder dysfunction. A severity categorization of the detrusor overactivity can be facilitated by the use of the ice water test nomogram. After further validation, the ice water test could be ultimately used in future as objective assessment for bladder dysfunction.

Association Between Gut Microbiota and Helicobacter pylori-Related Gastric Lesions in a High-Risk Population of Gastric Cancer

Eradication of Helicobacter pylori has been found to be effective for gastric cancer prevention, but uncertainties remain about the possible adverse consequences such as the potential microbial dysbiosis. In our study, we investigated the association between gut microbiota and H. pylori-related gastric lesions in 47 subjects by deep sequencing of microbial 16S ribosomal RNA (rRNA) gene in fecal samples. The dominant phyla in fecal samples were Bacteroidetes, Firmicutes, and Proteobacteria with average relative abundances of 54.77, 31.37 and 12.91%, respectively. Microbial diversity analysis showed that observed species and Shannon index were increased in subjects with past or current H. pylori infection compared with negative subjects. As for the differential bacteria, the average relative abundance of Bacteroidetes was found to significantly decrease from H. pylori negative (66.16%) to past infection group (33.01%, p = 0.007), as well as from normal (76.49%) to gastritis (56.04%) and metaplasia subjects (46.83%, p = 0.027). For Firmicutes and Proteobacteria, the average relative abundances showed elevated trends in the past H. pylori infection group (47.11, 20.53%) compared to negative group (23.44, 9.05%, p = 0.068 and 0.246, respectively), and similar increased trends were also found from normal (18.23, 5.05%) to gastritis (35.31, 7.23%, p = 0.016 and 0.294, respectively) or metaplasia subjects (32.33, 20.07%, both p < 0.05). These findings suggest that the alterations of fecal microbiota, especially the dominant phyla of Bacteroidetes, Firmicutes and Proteobacteria, may be involved in the process of H. pylori-related gastric lesion progression and provide hints for future evaluation of microbial changes after H. pylori eradication.

Neural Network Analysis of Follow-Up Data in Primary Breast Cancer

This paper reports on the performance of a recently developed neural network environment incorporating likelihood-based optimization and complexity reduction techniques in the analysis of breast cancer follow-up data with the goal of building up a clinical decision support system. The inputs to the neural network include classical factors such as grading, age, tumor size, estrogen and progesterone receptor measurements, as well as tumor biological markers such as PAI-1 and uPA. The network learns the structural relationship between these factors and the follow-up data. Examples of neural models for relapse-free survival are presented, which are based on data from 784 breast cancer patients who received their primary therapy at the Department of Obstetrics and Gynecology, Technische Universität München, Germany. The performance of the neural analysis as quantified by various indicators (likelihood, Kaplan-Meier curves, log-rank tests) was very high. For example, dividing the patients into two equally sized groups based on the neural score (i.e., cutoff = median score) leads to an estimated difference in relapse-free survival of 40% or better (80% vs. 40%) after 10 years in Kaplan-Meier analysis. Evidence for factor interactions as well as for time-varying impacts is presented. The neural network weights included in the models are significant at the 5% level. The use of neural network analysis and scoring in combination with strong tumor biological factors such as uPA and PAI-1 appears to result in a very effective risk group discrimination. Considerable additional comparison of data from different patient series will be required to establish the generalization capability more firmly. Nonetheless, the improvement of risk group discrimination represents an important step toward the use of neural networks for decision support in a clinical framework and in making the most of biological markers.

Evaluation of Non-invasive Examinations of Coronary Artery Disease Using Information Theory

A method is presented which allows a stepwise selection of relevant variables for a diagnosis and also a sequential allocation bearing in mind the time-sequence and the expense in recording the variables. The method is based on an information-theoretical approach and is suitable for the application of qualitative variables. The method is presented using data concerning patients with suspected coronary artery disease, taking into consideration the fact that the variables are observed at different times.

Importance of Non-invasive Right and Left Ventricular Variables on Exercise Capacity in Patients with Tetralogy of Fallot Hemodynamics

Good quality of life correlates with a good exercise capacity in daily life in patients with tetralogy of Fallot (ToF). Patients after correction of ToF usually develop residual defects such as pulmonary regurgitation or stenosis of variable severity. However, the importance of different hemodynamic parameters and their impact on exercise capacity is unclear. We investigated several hemodynamic parameters measured by cardiovascular magnetic resonance (CMR) and echocardiography and evaluated which parameter has the most pronounced effect on maximal exercise capacity determined by cardiopulmonary exercise testing (CPET). 132 patients with ToF-like hemodynamics were tested during routine follow-up with CMR, echocardiography and CPET. Right and left ventricular volume data, ventricular ejection fraction and pulmonary regurgitation were evaluated by CMR. Echocardiographic pressure gradients in the right ventricular outflow tract and through the tricuspid valve were measured. All data were classified and correlated with the results of CPET evaluations of these patients. The analysis was performed using the Random Forest model. In this way, we calculated the importance of the different hemodynamic variables related to the maximal oxygen uptake in CPET (VO₂%predicted). Right ventricular pressure showed the most important influence on maximal oxygen uptake, whereas pulmonary regurgitation and right ventricular enddiastolic volume were not important hemodynamic variables to predict maximal oxygen uptake in CPET. Maximal exercise capacity was only very weakly influenced by right ventricular enddiastolic volume and not at all by pulmonary regurgitation in patients with ToF. The variable with the most pronounced influence was the right ventricular pressure.

Development of an algorithm using clinical tests to avoid post-operative residual neuromuscular block

BACKGROUND

Quantitative neuromuscular monitoring is the gold standard to detect postoperative residual curarization (PORC). Many anesthesiologists, however, use insensitive, qualitative neuromuscular monitoring or unreliable, clinical tests. Goal of this multicentre, prospective, double-blinded, assessor controlled study was to develop an algorithm of muscle function tests to identify PORC.

METHODS

After extubation a blinded anesthetist performed eight clinical tests in 165 patients. Test results were correlated to calibrated electromyography train-of-four (TOF) ratio and to a postoperatively applied uncalibrated acceleromyography. A classification and regression tree (CART) was calculated developing the algorithm to identify PORC. This was validated against uncalibrated acceleromyography and tactile judgement of TOF fading in separate 100 patients.

RESULTS

After eliminating three tests with poor correlation, a model with four tests (r = 0.844) and uncalibrated acceleromyography (r = 0.873) were correlated to electromyographical TOF-values without losing quality of prediction. CART analysis showed that three consecutively performed tests (arm lift, head lift and swallowing or eye opening) can predict electromyographical TOF. Prediction coefficients reveal an advantage of the uncalibrated acceleromyography in terms of specificity to identify the EMG measured train-of-four ratio < 0.7 (100% vs. 42.9%) and <0.9 (89.7% vs. 34.5%) compared to the algorithm. However, due to the high sensitivity of the algorithm (100% vs. 94.4%), the risk to overlook an awake patient with a train-of-four ratio < 0.7 was minimal. Tactile judgement of TOF fading showed poorest sensitivity and specifity at train of four ratio < 0.9 (33.7%, 0%) and <0.7 (18.8%, 16.7%).

CONCLUSIONS

Residual neuromuscular blockade can be detected by uncalibrated acceleromyography and if not available by a pathway of four clinical muscle function tests in awake patients. The algorithm has a discriminative power comparable to uncalibrated AMG within TOF-values >0.7 and <0.3.

TRIAL REGISTRATION

Clinical Trials.gov (principal investigator's name: CU, and identifier: NCT03219138) on July 8, 2017.

Cut-off optimization for 13C-urea breath test in a community-based trial by mathematic, histology and serology approach

The performance of diagnostic tests in intervention trials of Helicobacter pylori (H.pylori) eradication is crucial, since even minor inaccuracies can have major impact. To determine the cut-off point for ¹³C-urea breath test (¹³C-UBT) and to assess if it can be further optimized by serologic testing, mathematic modeling, histopathology and serologic validation were applied. A finite mixture model (FMM) was developed in 21,857 subjects, and an independent validation by modified Giemsa staining was conducted in 300 selected subjects. H.pylori status was determined using recomLine H.pylori assay in 2,113 subjects with a borderline ¹³C-UBT results. The delta over baseline-value (DOB) of 3.8 was an optimal cut-off point by a FMM in modelling dataset, which was further validated as the most appropriate cut-off point by Giemsa staining (sensitivity = 94.53%, specificity = 92.93%). In the borderline population, 1,468 subjects were determined as H.pylori positive by recomLine (69.5%). A significant correlation between the number of positive H.pylori serum responses and DOB value was found (r_s = 0.217, P < 0.001). A mathematical approach such as FMM might be an alternative measure in optimizing the cut-off point for ¹³C-UBT in community-based studies, and a second method to determine H.pylori status for subjects with borderline value of ¹³C-UBT was necessary and recommended.

Quality of life in women of non-reproductive age with transvaginal mesh repair for pelvic organ prolapse: A cohort study

BACKGROUND

Transvaginal mesh repair has been discredited due to high complications rates in the past years. Therefore, we evaluated the quality of life (QoL) and complication rates after transvaginal mesh (TVM) repair for pelvic organ prolapse (POP).

METHODS

A total of 148 women who underwent TVM repair for symptomatic POP were retrospectively enrolled. Complication rates and functional outcomes were retrospectively assessed and validated, standardised questionnaires were used prospectively for evaluation of QoL. Univariate analysis by the chi(2)-test as well as a multivariate Cox regression analysis was conducted to predict mesh exposure using various variables as predictors.

RESULTS

Intraoperative complications with bowel or bladder injury appeared in 3.4%. Mesh exposure occurred in 2.7% whereas surgical revision was necessary only in 1.4%. No predictor for mesh exposure could be identified. Postoperative complications according to Clavien-Dindo classification ≥ III occurred in only 2.8%. An improvement of POP-symptoms was reported by 84.6% according the "patients' global impression of improvement" (PGI-I) and 88.2% women would repeat the surgery. The results of the "prolapse-quality of life"-questionnaire were comparable to asymptomatic women. Only 33% reported vaginal pain with a mean vaginal pain score of 0.6 according the international index of pain. Of sexually active women, 29% reported sexual impairments and mean score of sexual impairment was 1.52.

CONCLUSION

Low complication rates and a quality of life comparable to asymptomatic women following TVM repair could be achieved in our cohort. However, a high number of sexual impairments was identified although the impact of impairment was marginal.

A large randomised controlled intervention trial to prevent gastric cancer by eradication of Helicobacter pylori in Linqu County, China: baseline results and factors affecting the eradication

OBJECTIVE

To clarify the full range of benefits and adverse consequences of Helicobacter pylori eradication as a strategy for gastric cancer prevention, the community-based intervention trial was launched in Linqu County, China.

DESIGN

A total of 184,786 residents aged 25-54 years were enrolled in this trial and received (13)C-urea breath test. H. pylori positive participants were assigned into two groups, either receiving a 10-day quadruple anti-H. pylori treatment or lookalike placebos together with a single dosage of omeprazole and bismuth.

RESULTS

The prevalence of H. pylori in trial participants was 57.6%. A total of 94,101 subjects completed the treatment. The overall H. pylori eradication rate was 72.9% in the active group. Gender, body mass index, history of stomach disease, baseline delta over baseline-value of (13)C-urea breath test, missed medication doses, smoking and drinking were independent predictors of eradication failure. The missed doses and high baseline delta over baseline-value were important contributors in men and women (all Ptrend<0.001). However, a dose-response relationship between failure rate and smoking or drinking index was found in men (all Ptrend<0.001), while high body mass index (Ptrend<0.001) and history of stomach disease were significant predictors in women. The treatment failure rate increased up to 48.8% (OR 2.87, 95% CI 2.24 to 3.68) in men and 39.4% (OR 2.67, 95% CI 1.61 to 4.42) in women with multiple factors combined.

CONCLUSIONS

This large community-based intervention trial to eradicate H. pylori is feasible and acceptable. The findings of this trial lead to a distinct evaluation of factors influencing eradication that should be generally considered for future eradication therapies.

TRIAL REGISTRATION NUMBER

ChiCTR-TRC-10000979 in accordance with WHO ICTRP requirements.

The E3 ligase RNF43 inhibits Wnt signaling downstream of mutated β-catenin by sequestering TCF4 to the nuclear membrane

Given its fundamental role in development and cancer, the Wnt-β-catenin signaling pathway is tightly controlled at multiple levels. RING finger protein 43 (RNF43) is an E3 ubiquitin ligase originally found in stem cells and proposed to inhibit Wnt signaling by interacting with the Wnt receptors of the Frizzled family. We detected endogenous RNF43 in the nucleus of human intestinal crypt and colon cancer cells. We found that RNF43 physically interacted with T cell factor 4 (TCF4) in cells and tethered TCF4 to the nuclear membrane, thus silencing TCF4 transcriptional activity even in the presence of constitutively active mutants of β-catenin. This inhibitory mechanism was disrupted by the expression of RNF43 bearing mutations found in human gastrointestinal tumors, and transactivation of the Wnt pathway was observed in various cells and in Xenopus embryos when the RING domain of RNF43 was mutated. Our findings indicate that RNF43 inhibits the Wnt pathway downstream of oncogenic mutations that activate the pathway. Mimicking or enhancing this inhibitory activity of RNF43 may be useful to treat cancers arising from aberrant activation of the Wnt pathway.

Impingement-free range of movement, acetabular component cover and early clinical results comparing ‘femur-first’ navigation and ‘conventional’ minimally invasive total hip arthroplasty

We report the kinematic and early clinical results of a patient- and observer-blinded randomised controlled trial in which CT scans were used to compare potential impingement-free range of movement (ROM) and acetabular component cover between patients treated with either the navigated ‘femur-first’ total hip arthroplasty (THA) method (n = 66; male/female 29/37, mean age 62.5 years; 50 to 74) or conventional THA (n = 69; male/female 35/34, mean age 62.9 years; 50 to 75). The Hip Osteoarthritis Outcome Score, the Harris hip score, the Euro-Qol-5D and the Mancuso THA patient expectations score were assessed at six weeks, six months and one year after surgery. A total of 48 of the patients (84%) in the navigated ‘femur-first’ group and 43 (65%) in the conventional group reached all the desirable potential ROM boundaries without prosthetic impingement for activities of daily living (ADL) in flexion, extension, abduction, adduction and rotation (p = 0.016). Acetabular component cover and surface contact with the host bone were > 87% in both groups. There was a significant difference between the navigated and the conventional groups’ Harris hip scores six weeks after surgery (p = 0.010). There were no significant differences with respect to any clinical outcome at six months and one year of follow-up. The navigated ‘femur-first’ technique improves the potential ROM for ADL without prosthetic impingement, although there was no observed clinical difference between the two treatment groups.

Cite this article: Bone Joint J 2015; 97-B:890–8.

Estimation of a predictor's importance by Random Forests when there is missing data: risk prediction in liver surgery using laboratory data

Abstract In the last few decades, new developments in liver surgery have led to an expanded applicability and an improved safety. However, liver surgery is still associated with postoperative morbidity and mortality, especially in extended resections. We analyzed a large liver surgery database to investigate whether laboratory parameters like haemoglobin, leucocytes, bilirubin, haematocrit and lactate might be relevant preoperative predictors. It is not uncommon to observe missing values in such data. This also holds for many other data sources and research fields. For analysis, one can make use of imputation methods or approaches that are able to deal with missing values in the predictor variables. A representative of the latter are Random Forests which also provide variable importance measures to assess a variable's relevance for prediction. Applied to the liver surgery data, we observed divergent results for the laboratory parameters, depending on the method used to cope with missing values. We therefore performed an extensive simulation study to investigate the properties of each approach. Findings and recommendations: Complete case analysis should not be used as it distorts the relevance of completely observed variables in an undesirable way. The estimation of a variable's importance by a self-contained measure that can deal with missing values appropriately reflects the decreased relevance of variables with missing values. It can therefore be used to obtain insight into Random Forests which are commonly fit without preprocessing of missing values in the data. By contrast, multiple imputation allows for the assessment of a variable's relevance one would potentially observe in complete-data situations, if imputation performs well. For the laboratory data, lactate and bilirubin seem to be associated with the risk of liver failure and postoperative complications. These relations should be investigated by future studies in more detail. However, it is important to carefully consider the method used for analysis when there are missing values in the predictor variables.

Healthy living in pregnancy: a cluster-randomized controlled trial to prevent excessive gestational weight gain - rationale and design of the GeliS study

Background

Recent studies suggest that excessive gestational weight gain (GWG) leads to adverse maternal and fetal outcomes including weight retention in the mother and an increased risk of childhood obesity in the offspring.

The aim of the GeliS study is to examine the effect of a lifestyle intervention programme during pregnancy to avoid excessive GWG and, hence, to reduce pregnancy and obstetric complications as well as the risk of maternal and offspring obesity.

Methods and design

The GeliS study is a multicentre cluster-randomized controlled trial. A total number of 2500 pregnant women (singleton pregnancy) with a pre-pregnancy BMI ≥ 18.5 kg/m² and ≤ 40 kg/m² will be recruited in practices of gynaecologists and midwives in ten Bavarian regions. The intervention comprises three structured and individualised counselling sessions on a healthy diet, regular physical activity as well as weight monitoring during pregnancy and one session after delivery, respectively. The counselling sessions are attached to routine pre- and postnatal visits using standardised materials and procedures. In the control regions, general recommendations for a healthy lifestyle are given. An oral glucose tolerance test is offered to all participants.

The primary outcome is the proportion of participants with excessive GWG. Secondary outcomes include pregnancy and obstetric complications such as frequency of gestational diabetes, preeclampsia and caesarean sections as well as weight retention in the mothers and BMI and other health variables in the offspring. A 5-year follow-up of both mothers and their infants is planned.

Discussion

The GeliS lifestyle intervention programme has been adapted to the existing routine health care system for pregnant women. If shown to be effective, it could be immediately implemented in routine care.

Trial registration

The study protocol is registered at the ClinicalTrials.gov Protocol Registration System (NCT01958307).

Helicobacter pylori antibody responses and evolution of precancerous gastric lesions in a Chinese population

Helicobacter pylori-specific proteins are involved in gastric carcinogenesis. To investigate the seroprevalence of six H. pylori-specific antibodies in patients with different gastric histology, and the impact of seropositivities on the evolution of precancerous gastric lesions, a follow-up study was conducted in Linqu County, China. The seropositivities for CagA, VacA, GroEL, UreA, HcpC and gGT were assessed by recomLine analysis in 573 H. pylori-positive subjects and correlated with evolution of precancerous gastric lesions. We found that the score of H. pylori recomLine test was significantly increased in subjects with chronic atrophic gastritis (CAG, p < 0.0001) or intestinal metaplasia (IM, p = 0.0125), and CagA was an independent predictor of advanced gastric lesions, adjusted odds ratios (ORs) were 2.54 (95% CI = 1.42-4.55) for IM and 2.38 (95% CI = 1.05-5.37) for dysplasia (DYS). Moreover, seropositivities for CagA and GroEL were identified as independent predictors for progression of gastric lesions in a longitudinal study, and ORs were 2.89 (95% CI = 1.27-6.59) and 2.20 (95% CI = 1.33-3.64), respectively. Furthermore, the risk of progression was more pronounced in subjects with more than three positive antigens (p(for) trend = 0.0003). This population-based study revealed that seropositivities for CagA and GroEL might be potential markers to identify patients infected with high-risk H. pylori strains, which are related to the development of GC in a Chinese high-risk population, and recomLine test might serve as a tool for risk stratification.

Hypothenar hammer syndrome: a multicenter case-control study

BACKGROUND

The rarely diagnosed hypothenar hammer syndrome (HHS) is due to vascular damage to the distal part of the ulnar artery probably caused by acute or repetitive blunt trauma to the hypothenar region. To date, mainly case reports have been published, while epidemiological data are almost absent.

AIM

To identify potential risk factors for HHS.

METHOD

An interview-based multicenter case-control study of 71 patients with HHS and 105 matched controls was conducted with standardized questions regarding disease specific variables, occupation, exposure of the hands to different types of trauma in occupational and leisure context. Medical data were verified from individual medical records.

RESULTS

Multivariable logistic regression analysis revealed that using the hand as a hammer on a daily basis (adjusted odds ratio [aOR] 17.04, 95% CI 5.51-52.67) daily pressure to the palm of the hand (aOR 4.96, 95% CI 1.39-17.71), and daily exposure to vibrating tools (aOR 3.41, 95% CI 1.03-11.31) were significant risk factors for HHS.

CONCLUSIONS

This investigation represents one of the largest groups of patients with HHS described so far. Work-related repeated blunt trauma to the palm of the hand significantly increases the risk of HHS.