New duality results for evenly convex optimization problems

We present new results on optimization problems where the involved functions are evenly convex. By means of a generalized conjugation scheme and the perturbation theory introduced by Rockafellar, we propose an alternative dual problem for a general optimization one defined on a separated locally convex topological space. Sufficient conditions for converse and total duality involving the even convexity of the perturbation function and c-subdifferentials are given. Formulae for the c-subdifferential and biconjugate of the objective function of a general optimization problem are provided, too. We also characterize the total duality by means of the saddle-point theory for a notion of Lagrangian adapted to the considered framework.

Dynamic Treatment Stratification Using ctDNA

An accurate profiling of the genomic landscape is mandatory to establish the best clinical and therapeutic approach for patients with solid malignancies. Moreover, tumor cells constantly adapt to external pressures-i.e., systemic treatment-with the selection and expansion of resistant subclones and the emergence of heterogeneous overlapping genomic alterations of resistance. The current standard for molecular characterization in cancer is the performance of a tissue tumor biopsy at the time of diagnosis and, when possible, a re-biopsy at the time of progression. However, tissue biopsy is not always feasible or practical and may underestimate tumor heterogeneity and clonal dynamics. Circulating DNA fragments carrying tumor-specific sequence alterations (circulating tumor DNA, ctDNA) are released from cancer cells into the bloodstream, representing a variable and generally small fraction of the total circulating cell-free DNA. Tumor genotyping in ctDNA (liquid biopsy) offers potential advantages versus the standard tumor tissue biopsy, including non-invasiveness and representation of molecular heterogeneity. Technical advances in sequencing platforms have led to dramatic improvements in variant detection sensitivity and specificity that allow for the detection and quantification of low levels of ctDNA. This provides valuable information on both actionable mutations and captures real-time variations in tumor dynamics. Liquid biopsy clinical applications include molecular diagnosis, determination of tumor load as a surrogate marker of early response, monitoring of mutations of resistance to targeted therapy and detection of minimal residual disease after cancer surgery. The aim of this chapter is to provide an overview of the biological rational and technical background of ctDNA analysis, as well as on the main clinical applications of liquid biopsy in dynamic treatment stratification in solid tumors. Special emphasis will be made on the current and potential benefits of the implementation of ctDNA in clinical practice, mainly in melanoma, lung, and colorectal cancer.

Anesthetic management of the diaphragmatic pacemaker placement surgery. Our experience in the Institut Guttmann

BACKGROUND

The diaphragm pacemaker (DP) has proven its utility in replacing mechanical ventilation in patients with chronic spinal cord injury (SCI) and amyotrophic lateral sclerosis (ALS). The DP improves patient quality of life and reduces morbidity and mortality and their associated health care costs. The anesthetic management of these patients and the particularities of the surgical procedure are challenging. The aim of our study is to analyze anesthetic management and intraoperative complications in patients undergoing DP placement in our hospital.

METHODS

We performed a chart review of patients treated between December 2007 and July 2017, recording the patients' preoperative status, anesthetic management and intraoperative complications.

RESULTS

The study included 16 patients (5 pediatric) undergoing DP implantation for chronic SCI (63%), ALS (25%) and other neurologic conditions (12%). Abdominal laparoscopy was performed under general anesthesia, with intravenous (87%) or inhalational (13%) induction and maintenance using total intravenous (50%) or balanced (50%) anesthesia. Rocuronium was administered in one case to permit airway management. Complications included: hypotension (50%), difficulties in mechanical ventilation during laparoscopy (31%), pneumothorax (12.5%) and autonomic dysreflexia (6%).

CONCLUSIONS

DP placement under general anesthesia is a safe intervention in both adult and pediatric patients. Complications derived from both the underlying disease and the surgical technique may appear, and must be rapidly identified and treated to obtain a satisfactory surgical outcome.

482Direct oral anticoagulant rivaroxaban in very old and frail patients: A one-year prospective follow-up of a large-scale cohort (SAFIR-AC)

Background/Introduction

Age is one of the strongest predictors/risk factors for ischemic stroke in subjects with atrial fibrillation (AF). Direct oral anticoagulants (DOACs) have been shown to be effective in the prevention of this condition; however, clinical evidence on bleeding risk with this therapeutic strategy in very old and frail geriatric patients is poor.

Purpose

To assess bleeding risk in French geriatric patients aged ≥80 years and diagnosed with AF newly treated with rivaroxaban.

Methods

Subjects, presenting to one of 33 geriatric centers, with non-valvular AF and recent initiation of a treatment with rivaroxaban were enrolled in the study and followed-up every 3 months for 12 months. Clinical and routine laboratory data and evaluation scores, such as HAS-BLED, HEMORR2HAGES, ATRIA, and CHA2DS2-VASc, as well as comprehensive geriatric evaluation were reported. Major bleeding, as defined in ROCKET AF study, was reported at each visit, and this primary outcome was adjudicated by an independent committee. Results of this cohort were compared with findings from a similar cohort treated with vitamin K antagonists (VKAs) from the same centers (n=924).

Results

A total of 1045 subjects were enrolled in the study of whom 995 (95%) had a one-year follow-up (analyzed population). The mean (standard deviation (SD)) age was 86.0 (4.3) years, with the majority of patients being female (61%), 23% aged 90 years or older, and 48% having an estimated glomerular filtration rate (eGFR) <50 mL/min. The main comorbidities were hypertension in 77% of subjects, malnutrition 49%, anemia 43%, dementia 39%, heart failure 36%, and falls 27%. The mean (SD) score for CHA2DS2-VASc was 4.8 (1.4), HAS-BLED 2.4 (0.9), Mini-Mental State Examination (MMSE) 21.5 (6.9), Activities of Daily Living (ADL) 4.4 (1.9), and Charlson Comorbidity Index 6.7 (2.0). The one-year rate of major bleeding events was 6.4% of which 0.8% were fatal and 1.1% intracranial hemorrhages (ICH), whereas the one-year rate of ischemic stroke was 1.4% and all-cause mortality 17.9%. Computed with VKA cohort findings and adjusted for age, gender, eGFR and Charlson score, this would result in a hazard ratio of 0.54 (95% confidence interval [CI], 0.38 to 0.78) for major bleeding, 0.36 (0.17 to 0.76) for ICH, 0.62 (0.29 to 1.33) for ischemic stroke, and 0.82 (0.65 to 1.02) for all-cause mortality, in favor of rivaroxaban.

Conclusions

This is the first large-scale prospective study in geriatric population in AF subjects treated with DOAC (rivaroxaban) Major bleeding risk appeared higher in very old than younger population, however major bleeding and ICH rates were significantly lower with rivaroxaban than with VKAs when used in the same geriatric population. This study indicates that Rivaroxaban can be used in very old and frail patients for the treatment of non-valvular AF.

Acknowledgement/Funding

Unrestricted grant from Bayer

Dessine-moi une réalité plus belle : la réalité virtuelle vue par les patientes atteintes d’un cancer du sein

Une enquête réalisée auprès de 300 femmes atteintes d’un cancer du sein a permis d’examiner leur intérêt pour la réalité virtuelle (RV), les modalités d’immersion attendues ainsi que leurs attentes vis-à-vis de ce dispositif. Les résultats indiquent que la majorité des femmes (93 %) souhaiterait avoir recours à la RV durant leurs traitements, sachant que leurs préférences d’immersion portent sur un environnement naturel accompagné de musique et/ou de relaxation guidée. La RV est envisagée comme un outil pertinent pour s’évader, mieux accepter les soins et réguler leurs émotions. Pour faciliter l’immersion virtuelle, cette étude souligne combien il est important de connaître leurs aspirations personnelles pour leur offrir un soutien technologique individualisé.

Ultra-selection of metastatic colorectal cancer patients using next-generation sequencing to improve clinical efficacy of anti-EGFR therapy

BACKGROUND

Extended RAS analysis is mandatory in metastatic colorectal cancer (mCRC) patients. The optimal threshold of RAS mutated subclones to identify patients most likely to benefit from antiepidermal growth factor receptor (EGFR) therapy is controversial. Our aim was to assess the clinical impact of detecting mutations in RAS, BRAF, PIK3CA and EGFRS492R in basal tissue tumour samples by using a highly sensitive next-generation sequencing (NGS) technology in mCRC patients treated with chemotherapy plus anti-EGFR or anti-vascular endothelial growth factor.

PATIENTS AND METHODS

Five hundred and eighty-one tumour samples from untreated mCRC patients from 7 clinical studies were collected. Mutational analysis was carried out by standard-of-care (therascreen pyro) with a sensitivity detection of 5% mutant allele fraction (MAF), and compared with NGS technology using 454GS Junior platform (Roche Applied Science, Germany) with a sensitivity of 1%. Molecular results were correlated with clinical outcomes.

RESULTS

After quality assessment, 380 samples were evaluable for molecular analysis. Standard-of-care mutational analysis detected RAS, BRAFV600E or PIK3CA mutations in 56.05% of samples compared with 69.21% by NGS (P = 0.00018). NGS identified coexistence of multiple low-frequency mutant alleles in 96 of the 263 mutated cases (36.5%; range 2-7). Response rate (RR), progression-free survival (PFS) and overall survival (OS) were increasingly improved in patients with RAS wild-type, RAS/BRAF wild-type or quadruple (KRAS/NRAS/BRAF/PIK3CA) wild-type tumours treated with anti-EGFR, assessed by standard-of-care. No additional benefit in RR, PFS or OS was observed by increasing the detection threshold to 1% by NGS. An inverse correlation between the MAF of the most prevalent mutation detected by NGS and anti-EGFR response was observed (P = 0.039). EGFRS492Rmutation was not detected in untreated samples.

CONCLUSIONS

No improvement in the selection of patients for anti-EGFR therapy was obtained by adjusting the mutation detection threshold in tissue samples from 5% to 1% MAF. Response to anti-EGFR was significantly better in patients with quadruple wild-type tumours.

Fermented dairy products, diet quality, and cardio-metabolic profile of a Mediterranean cohort at high cardiovascular risk

BACKGROUND AND AIMS

Fermented dairy products have been associated with a better diet quality and cardio-metabolic profile. However, in Mediterranean populations, these associations have not been well characterized. The aim of this study was to assess the diet quality and the associations between the consumption of total fermented dairy products and their subtypes and the prevalence of Metabolic Syndrome (MetS) components in a Mediterranean population at high cardiovascular risk.

METHODS AND RESULTS

Baseline cross-sectional analyses were conducted on 6,572 men and women (mean age: 65 years) with overweight or obesity and MetS recruited into the PREDIMED-Plus cohort. A 143-item Food Frequency Questionnaire (FFQ) was used, and anthropometrical, biochemical, and blood pressure measurements were recorded. Multivariate-adjusted Cox regressions were fitted to analyze the association between quartiles of consumption of fermented dairy products and their subtypes and MetS components to estimate the relative risk (RR) and 95% confidence intervals (95% CIs). Participants who were high consumers of fermented dairy products reported a higher consumption of fruit, vegetables, fish, nuts, and whole bread and a lower consumption of white bread, alcohol, and cookies. Participants in the higher quartile showed a lower prevalence of the low HDL-cholesterol component of the MetS (RR=0.88; 95% CI: 0.78-0.98) than those in the lowest quartile of cheese consumption. Cheese consumption was inversely associated with the prevalence of hypertriglyceridemia. Total fermented dairy products, yogurt, and its types were not associated with any of the MetS components.

CONCLUSIONS

Compared to nonconsumers, participants consuming fermented dairy products reported a better diet quality and, particularly, cheese consumers presented a lower prevalence of hypertriglyceridemia and low HDL-cholesterol plasma levels, which are MetS components.

Circulating tumor cells (CTCs) and cytokeratin 19 (CK19) mRNA as prognostic factors in heavily pretreated patients with metastatic breast cancer

INTRODUCTION

Circulating tumor cell (CTC) count and cytokeratin 19 (CK19) mRNA expression have a prognostic value for patients with metastatic breast cancer (MBC), but their clinical utility remains controversial. We studied CTC count and CK19 mRNA expression in the peripheral blood samples from heavily pretreated patients with MBC and their correlations with prognosis and response to the subsequent line of therapy.

METHODS

This prospective observational study included 67 consecutive patients with MBC who were on progression to systemic therapy, and criteria for a new line of systemic treatment were proposed outside a clinical trial. CTC counts and CK19 mRNA expression were measured by the CellSearch^® and RT-PCR methods, respectively, before and after the first cycle of treatment. Progression-free survival (PFS) was defined as the time elapsed between the initiation of the treatment and either the date of clinical or radiological tumor progression or death from any cause or the last follow-up. Cox proportional hazards regression model was used to assess the univariate prognostic value of CTC and CK19 mRNA expression on PFS and Kaplan-Meier estimates. A multivariate Cox model was also used to additionally account for phenotype and visceral disease.

RESULTS

The mean age was 60 (range 35-86) years, and the average number of previous treatments was 3 (range 1-10); 42 patients (62.6%) were ER+ and 38 patients (56.7%) had visceral disease. The median PFS rate was 8 months (95% CI: 3.7-8.2). Univariate analyses showed a significant effect of the initial value of CK19 mRNA expression (HR = 2.00; 95% CI: 1.05-3.8; p = 0.03) and for the second value of CTC (HR = 2.18; 95% CI: 1.22-3.9; p = 0.009) but did not reach statistical significance for the initial value of CTC and the second value of CK19 mRNA expression. The estimated PFS rates at 6 and 12 months were 75% and 31% for patients with a low initial value of CK19 mRNA expression and 36% and 10% for those with a high initial value of CK19 mRNA expression, respectively (p: 0.022). Further, the estimated PFS rates at 6 and 12 months were 86% and 65% for patients with a low second value of CTC and 76% and 47% for those with a high second value of CTC, respectively (p: 0.004). In the multivariate analysis adjusted for phenotype, visceral disease, and the last treatment performed, only the effect of the second value of CTC remained significant (HR = 2.7, p = 0.004).

CONCLUSIONS

CK19 mRNA expression and CTC count appeared clinically meaningful in pretreated patients with MBC, even when adjusted for phenotype and visceral disease involvement. These results support the use of CK19 and CTC as relevant biomarkers for predicting clinical response in MBC.

Efficacy of Sym004 in Patients With Metastatic Colorectal Cancer With Acquired Resistance to Anti-EGFR Therapy and Molecularly Selected by Circulating Tumor DNA Analyses: A Phase 2 Randomized Clinical Trial

IMPORTANCE

Acquired resistance to anti-EGFR therapy (epidermal growth factor receptor) is frequently due to RAS and EGFR extracellular domain (ECD) mutations in metastatic colorectal cancer (mCRC). Some anti-EGFR-refractory patients retain tumor EGFR dependency potentially targetable by agents such as Sym004, which is a mixture of 2 nonoverlapping monoclonal antibodies targeting EGFR.

OBJECTIVE

To determine if continuous blockade of EGFR by Sym004 has survival benefit.

DESIGN, SETTING, AND PARTICIPANTS

Multicenter, phase 2, randomized, clinical trial comparing 2 regimens of Sym004 with investigator's choice from March 6, 2014, through October 15, 2015. Circulating tumor DNA (ctDNA) was analyzed for biomarker and tracking clonal dynamics during treatment. Participants had wild-type KRAS exon 2 mCRC refractory to standard chemotherapy and acquired resistance to anti-EGFR monoclonal antibodies.

INTERVENTIONS

Participants were randomly assigned in a 1:1:1 ratio to Sym004, 12 mg/kg/wk (arm A), Sym004, 9 mg/kg loading dose followed by 6 mg/kg/wk (arm B), or investigator's choice of treatment (arm C).

MAIN OUTCOMES AND MEASURES

Overall survival (OS). Secondary end points included preplanned exploratory biomarker analysis in ctDNA.

RESULTS

A total of 254 patients were randomized (intent-to-treat [ITT] population) (median age, 63 [range, 34-91] years; 63% male; n = 160). Median OS in the ITT population was 7.9 months (95% CI, 6.5-9.9 months), 10.3 months (95% CI, 9.0-12.9 months), and 9.6 months (95% CI, 8.3-12.2 months) for arms A, B, and C, respectively (hazard ratio [HR], 1.31; 95% CI, 0.92-1.87 for A vs C; and HR, 0.97; 95% CI, 0.68-1.40 for B vs C). The ctDNA revealed high intrapatient genomic heterogeneity following anti-EGFR therapy. Sym004 effectively targeted EGFR ECD-mutated cancer cells, and a decrease in EGFR ECD ctDNA occurred in Sym004-treated patients. However, this did not translate into clinical benefit in patients with EGFR ECD mutations, likely owing to co-occurring resistance mechanisms. A subgroup of patients was defined by ctDNA (RAS/BRAF/EGFR ECD-mutation negative) associated with improved OS in Sym004-treated patients in arm B compared with arm C (median OS, 12.8 and 7.3 months, respectively).

CONCLUSIONS AND RELEVANCE

Sym004 did not improve OS in an unselected population of patients with mCRC and acquired anti-EGFR resistance. A prospective clinical validation of Sym004 efficacy in a ctDNA molecularly defined subgroup of patients with refractory mCRC is warranted.

TRIAL REGISTRATION

clinicaltrialsregister.eu Identifier: 2013-003829-29.

Concordance of blood- and tumor-based detection of RAS mutations to guide anti-EGFR therapy in metastatic colorectal cancer

Background

Circulating tumor DNA (ctDNA) is a potential source for tumor genome analysis. We explored the concordance between the mutational status of RAS in tumor tissue and ctDNA in metastatic colorectal cancer (mCRC) patients to establish eligibility for anti-epidermal growth factor receptor (EGFR) therapy.

Patients and methods

A prospective-retrospective cohort study was carried out. Tumor tissue from 146 mCRC patients was tested for RAS status with standard of care (SoC) PCR techniques, and Digital PCR (BEAMing) was used both in plasma and tumor tissue.

Results

ctDNA BEAMing RAS testing showed 89.7% agreement with SoC (Kappa index 0.80; 95% CI 0.71 − 0.90) and BEAMing in tissue showed 90.9% agreement with SoC (Kappa index 0.83; 95% CI 0.74 − 0.92). Fifteen cases (10.3%) showed discordant tissue-plasma results. ctDNA analysis identified nine cases of low frequency RAS mutations that were not detected in tissue, possibly due to technical sensitivity or heterogeneity. In six cases, RAS mutations were not detected in plasma, potentially explained by low tumor burden or ctDNA shedding. Prediction of treatment benefit in patients receiving anti-EGFR plus irinotecan in second- or third-line was equivalent if tested with SoC PCR and ctDNA. Forty-eight percent of the patients showed mutant allele fractions in plasma below 1%.

Conclusions

Plasma RAS determination showed high overall agreement and captured a mCRC population responsive to anti-EGFR therapy with the same predictive level as SoC tissue testing. The feasibility and practicality of ctDNA analysis may translate into an alternative tool for anti-EGFR treatment selection.

Plasma ctDNA RAS mutation analysis for the diagnosis and treatment monitoring of metastatic colorectal cancer patients

Background

RAS assessment is mandatory for therapy decision in metastatic colorectal cancer (mCRC) patients. This determination is based on tumor tissue, however, genotyping of circulating tumor (ct)DNA offers clear advantages as a minimally invasive method that represents tumor heterogeneity. Our study aims to evaluate the use of ctDNA as an alternative for determining baseline RAS status and subsequent monitoring of RAS mutations during therapy as a component of routine clinical practice.

Patients and methods

RAS mutational status in plasma was evaluated in mCRC patients by OncoBEAM™ RAS CRC assay. Concordance of results in plasma and tissue was retrospectively evaluated. RAS mutations were also prospectively monitored in longitudinal plasma samples from selected patients.

Results

Analysis of RAS in tissue and plasma samples from 115 mCRC patients showed a 93% overall agreement. Plasma/tissue RAS discrepancies were mainly explained by spatial and temporal tumor heterogeneity. Analysis of clinico-pathological features showed that the site of metastasis (i.e. peritoneal, lung), the histology of the tumor (i.e. mucinous) and administration of treatment previous to blood collection negatively impacted the detection of RAS in ctDNA. In patients with baseline mutant RAS tumors treated with chemotherapy/antiangiogenic, longitudinal analysis of RAS ctDNA mirrored response to treatment, being an early predictor of response. In patients RAS wt, longitudinal monitoring of RAS ctDNA revealed that OncoBEAM was useful to detect emergence of RAS mutations during anti-EGFR treatment.

Conclusion

The high overall agreement in RAS mutational assessment between plasma and tissue supports blood-based testing with OncoBEAM™ as a viable alternative for genotyping RAS of mCRC patients in routine clinical practice. Our study describes practical clinico-pathological specifications to optimize RAS ctDNA determination. Moreover, OncoBEAM™ is useful to monitor RAS in patients undergoing systemic therapy to detect resistance and evaluate the efficacy of particular treatments.

Analysis of the evolution of cortical and trabecular bone compartments in the proximal femur after spinal cord injury by 3D-DXA

Marked trabecular and cortical bone loss was observed at the proximal femur short-term after spinal cord injury (SCI). 3D-DXA provided measurement of vBMD evolution at both femoral compartments and cortical thinning, thereby suggesting that this technique could be useful for bone analysis in these patients.

INTRODUCTION

SCI is associated with a marked increase in bone loss and risk of osteoporosis development short-term after injury. 3D-DXA is a new imaging analysis technique providing 3D analysis of the cortical and trabecular bone from DXA scans. The aim of this study was to assess the evolution of trabecular macrostructure and cortical bone using 3D-DXA in patients with recent SCI followed over 12 months.

METHODS

Sixteen males with recent SCI (< 3 months since injury) and without antiosteoporotic treatment were included. Clinical assessment, bone mineral density (BMD) measurements by DXA, and 3D-DXA evaluation at proximal femur (analyzing the integral, trabecular and cortical volumetric BMD [vBMD] and cortical thickness) were performed at baseline and at 6 and 12 months of follow-up.

RESULTS

vBMD significantly decreased at integral, trabecular, and cortical compartments at 6 months (- 8.8, - 11.6, and - 2.4%), with a further decrease at 12 months, resulting in an overall decrease of - 16.6, - 21.9, and - 5.0%, respectively. Cortical thickness also decreased at 6 and 12 months (- 8.0 and - 11.4%), with the maximal decrease being observed during the first 6 months. The mean BMD losses by DXA at femoral neck and total femur were - 17.7 and - 21.1%, at 12 months, respectively.

CONCLUSIONS

Marked trabecular and cortical bone loss was observed at the proximal femur short-term after SCI. 3D-DXA measured vBMD evolution at both femoral compartments and cortical thinning, providing better knowledge of their differential contributory role to bone strength and probably of the effect of therapy in these patients.

Subcritical Thermal Convection of Liquid Metals in a Rapidly Rotating Sphere

Planetary cores consist of liquid metals (low Prandtl number Pr) that convect as the core cools. Here, we study nonlinear convection in a rotating (low Ekman number Ek) planetary core using a fully 3D direct numerical simulation. Near the critical thermal forcing (Rayleigh number Ra), convection onsets as thermal Rossby waves, but as Ra increases, this state is superseded by one dominated by advection. At moderate rotation, these states (here called the weak branch and strong branch, respectively) are smoothly connected. As the planetary core rotates faster, the smooth transition is replaced by hysteresis cycles and subcriticality until the weak branch disappears entirely and the strong branch onsets in a turbulent state at Ek<10^{-6}. Here, the strong branch persists even as the thermal forcing drops well below the linear onset of convection (Ra=0.7Ra_{crit} in this study). We highlight the importance of the Reynolds stress, which is required for convection to subsist below the linear onset. In addition, the Péclet number is consistently above 10 in the strong branch. We further note the presence of a strong zonal flow that is nonetheless unimportant to the convective state. Our study suggests that, in the asymptotic regime of rapid rotation relevant for planetary interiors, thermal convection of liquid metals in a sphere onsets through a subcritical bifurcation.