The effect of spent coffee ground (SCG) loading, matrix ratio and biological treatment of SCG on poly(hydroxybutyrate) (PHB)/poly(lactic acid) (PLA) polymer blend

This study investigates the effects of SCG embedded into biodegradable polymer blends and aimed to formulate and characterise biomass-reinforced biocomposites using spent coffee ground (SCG) as reinforcement in PHB/PLA polymer blend. The effect of SCG filler loading and varying PHB/PLA ratios on the tensile properties and morphological characteristics of the biocomposites were examined. The results indicated that tensile properties reduction could be due to its incompatibility with the PHB/PLA matrixSCG aggregation at 40 wt% content resulted in higher void formation compared to lower content at 10 wt%. A PHB/PLA ratio of 50/50 with SCG loading 20 wt% was chosen for biocomposites with treated SCG. Biological treatment of SCG using Phanerochaete chrysosporium CK01 and Aspergillus niger DWA8 indicated P. chrysosporium CK01 necessitated a higher moisture content for optimum growth and enzyme production, whereas the optimal conditions for enzyme production (50-55 %, w/w) differed from those promoting A. niger DWA8 growth (40 %, w/w). SEM micrographs highlighted uniform distribution and effective wetting of treated SCG, resulting in improvements of tensile strength and modulus of biocomposites, respectively. The study demonstrated the effectiveness of sustainable fungal treatment in enhancing the interfacial adhesion between treated SCG and the PHB/PLA matrix.

Real-World Treatment Patterns of Older Adults with Locally Advanced SCCHN Using SEER-Medicare

PURPOSE/OBJECTIVE(S)

Roughly 50-67% of patients with squamous cell carcinomas of the head and neck (SCCHN) present with locally advanced (LA) disease and 65% of them relapse after initial therapy. The standard of care for LA SCCHN is definitive therapy (DT), a combination of surgery and or radiation therapy (RT), with or without platinum-based chemotherapy/cetuximab (chemo), that has been shown to optimize long term disease control. Few published analyses have characterized recent real-world treatment (Tx) patterns of older adults with LA SCCHN in the US.

MATERIALS/METHODS

We used the Surveillance, Epidemiology, and End Results (SEER)-Medicare database, a linkage of cancer registry and claims data, to identify patients diagnosed with LA SCCHN (first and only cancer) from 2010 to 2017 who initiated a relevant Tx (Tx initiation date defined as index date) and were continuously enrolled in Medicare Parts A, B, and D from 12 months pre-index until death or 12 months post-index. We used clinical guidelines regarding timing and frequency of treatments to build an algorithm that used Medicare claims to categorize initial Tx as non-DT, non-surgical DT (concomitant chemo+RT (cCRT) or chemotherapy before RT/cCRT), or surgical DT (surgery then RT/cCRT ± prior chemo).

RESULTS

We identified 1052 older adults with LA SCCHN (median age 73 years, 37% female, and 81% non-Hispanic white) whose initial treatment was started a median of 26 days after initial diagnosis. Of the 610 patients who received a DT as their initial Tx, 23.3% of patients had a subsequent Tx: 3.8% received immunotherapy-containing regimens (IO), and the most common subsequent Tx were surgery only (7.7%), chemotherapy only (3.6%), and RT only (3.4%). The median time to next Tx (TTNT) differed by DT category and primary tumor site. (Table 1) CONCLUSION: In this descriptive analysis, we provided an update on the Tx patterns of older adults with LA SCCHN in the US, for whom there have been no novel FDA approvals in over a decade. We found that a large proportion (42%) of patients did not receive DT regimens in the real-world setting despite known benefits in LA SCCHN. Roughly a quarter of patients required subsequent Tx. Availability of IO was low due to approvals after 2017. These findings suggest a need for novel therapies that can improve outcomes in LA SCCHN.

Racial Disparities in Survival of Patients with High-Risk LA SCCHN in the U.S

PURPOSE/OBJECTIVE(S)

Approximately 50-67% of patients with squamous cell carcinomas of the head and neck (SCCHN) present with locally advanced (LA) disease. Human papillomavirus (HPV) associated SCCHN has improved survival compared to non-HPV SCCHN. Studies have analyzed racial disparities in LA SCCHN but few have adjusted for HPV status and socio-economic status (SES). Our objective was to characterize disparities in LA SCCHN.

MATERIALS/METHODS

We identified high-risk patients from 2010-2017 with AJCC v8 Stage IVA/IVB SCCHN of the oral cavity, oropharynx (OP), larynx or hypopharynx, or Stage III SCCHN of the OP in the Surveillance, Epidemiology, and End Results (SEER) with HPV Status and Census Tract-level SES/Rurality Combined Database. We excluded OP patients with missing HPV data. SEER-reported treatment was used to classify initial treatment as definitive therapy (DT) categories: surgical DT, non-surgical DT or non-DT. The Kaplan Meier method was used to estimate overall survival (OS) with 95% confidence intervals (CI). Multivariable cox proportional hazard models were used for associations between covariates and hazard ratio (HR) of death, adjusted for age, sex, race, ethnicity, DT category, marital status, rurality, tumor size, cancer stage, and HPV status. We explored the impact of additionally adjusting for Yost SES index quintiles.

RESULTS

We identified 17,818 eligible patients: 79.3% White, 14.4% Black, 5.8% Asian/Pacific Islander (A/PI), and 0.6% American Indian/Alaska Native (AI/AN). Primary tumor sites were oral cavity (36.8%), larynx (29.0%), OP (24.4%), and hypopharynx (9.9%). 10.4% were HPV-associated. Race and SES quintiles were related (chi-squared, p<0.001) and the majority (56.5%) of black patients were in the lowest SES quintile. mOS was shorter and risk of death was significantly higher for black vs white patients in both the all-site and OP-only cohorts. When we added SES to multivariable analyses, Black race was no longer associated with increased risk of death in the all-site or OP-only cohorts. (Table 1) CONCLUSION: We found that when adjusting for sociodemographic and clinical factors, Black race was independently associated with a higher risk of death compared to white patients. When we adjusted for SES in multivariable analysis the association between Black race and risk of death was no longer significant, consistent with previously published analyses and indicative of a complex relationship between race and SES. Further research is needed to identify and address the causative factors of disparities in LA HNSCC.

A review of 100 iatrogenic nerve injuries: delays in referrals remain significant

INTRODUCTION

This is a retrospective study of 100 consecutive patients with iatrogenic nerve injuries, as seen in a tertiary referral centre over a six-year period.

MATERIALS AND METHODS

Patients who presented with new-onset nerve palsy involving a motor or mixed motor/sensory nerve following an operation were studied.

RESULTS

There were 44 male and 56 female patients with a mean age of 53 years (range 5-87 years). The median duration from the index procedures to referral was six months (range 0 days to 12 years). Approximately one third of referrals were made over 12 months since the index procedures. Twenty patients recovered spontaneously and were managed expectantly. Eighty patients underwent secondary interventions.

DISCUSSION

There remains a significant delay in referring postoperative nerve palsy to a nerve specialist. The majority of these cases will warrant secondary reconstructive surgery and delay in treatment may have a negative effect on the ultimate outcomes.

759 RELATIONSHIP BETWEEN G8 AND CFS IN A COHORT OF LUNG CANCER PATIENTS REFERRED TO A SPECIALISED ONCO-GERIATRIC CLINIC

Introduction

The International Society of Geriatric Oncology recommends using screening tools to identify cancer patients who would benefit from a comprehensive geriatric assessment. G8, a tool specifically designed for oncology, has been well validated in this setting (1). Rockwood Clinical frailty score (CFS) is a widely used tool to assess frailty, and has been adopted into standard assessments at many sites (2). However, this tool is less well validated in patients with cancer.

Methods

In this single site observational study we recorded CFS and G8 in 89 patients with lung cancer referred to a local onco-geriatrics clinic between 21/10/20 and 5/2/21. Both scores were available for 82 patients. We aimed to measure the correlation between G8 and CFS in this cohort.

Results

G8 score ≤ 14 is a referral criteria for the clinic, therefore 100% (82/82) of patients were classified as ‘frail’ using G8. Of these, only 23.2% (19/82) were classified as ‘mildly frail’ or worse using CFS (scores ≥5). Using Spearman’s rank correlation we found a very weak/negligible negative correlation between CFS and G8 (−0.2519, p = 0.0224).

Conclusion

The small proportion of patients (23.2%) classified as frail by CFS suggests that a G8 cut off of 14 may overestimate frailty. Previous work by our group has found that using a cut off of 13 is better able to predict chemotherapy outcomes(3). However, considering the lack of evidence for CFS in oncology, this poor correlation between G8 and CFS may question the usefulness of CFS in this context. (1) Decoster L, Puyvelde K, Mohile S, et al. Ann Oncol. 2015 Feb; 26(2): 288–300 (2) NHS Elect. [Online].; 2018 [cited 16/2/21] (3) A. Tivey, M. Ullah, A. Beech, et al. J Geriatr Oncol. 2020 Mar; 11(7).

A repeating fast radio burst source in a globular cluster

Fast radio bursts (FRBs) are flashes of unknown physical origin¹. The majority of FRBs have been seen only once, although some are known to generate multiple flashes^2,3. Many models invoke magnetically powered neutron stars (magnetars) as the source of the emission^4,5. Recently, the discovery⁶ of another repeater (FRB 20200120E) was announced, in the direction of the nearby galaxy M81, with four potential counterparts at other wavelengths⁶. Here we report observations that localized the FRB to a globular cluster associated with M81, where it is 2 parsecs away from the optical centre of the cluster. Globular clusters host old stellar populations, challenging FRB models that invoke young magnetars formed in a core-collapse supernova. We propose instead that FRB 20200120E originates from a highly magnetized neutron star formed either through the accretion-induced collapse of a white dwarf, or the merger of compact stars in a binary system⁷. Compact binaries are efficiently formed inside globular clusters, so a model invoking them could also be responsible for the observed bursts.

Pharmacological and clinical implications of local anaesthetic mixtures: a narrative review

Various techniques have been explored to prolong the duration and improve the efficacy of local anaesthetic nerve blocks. Some of these involve mixing local anaesthetics or adding adjuncts. We did a literature review of studies published between 01 May 2011 and 01 May 2021 that studied specific combinations of local anaesthetics and adjuncts. The rationale behind mixing long- and short-acting local anaesthetics to hasten onset and extend duration is flawed on pharmacokinetic principles. Most local anaesthetic adjuncts are not licensed for use in this manner and the consequences of untested admixtures and adjuncts range from making the solution ineffective to potential harm. Pharmaceutical compatibility needs to be established before administration. The compatibility of drugs from the same class cannot be inferred and each admixture requires individual review. Precipitation on mixing (steroids, non-steroidal anti-inflammatory drugs) and subsequent embolisation can lead to serious adverse events, although these are rare. The additive itself or its preservative can have neurotoxic (adrenaline, midazolam) and/or chondrotoxic properties (non-steroidal anti-inflammatory drugs). The prolongation of block may occur at the expense of motor block quality (ketamine) or block onset (magnesium). Adverse effects for some adjuncts appear to be dose-dependent and recommendations concerning optimal dosing are lacking. An important confounding factor is whether studies used systemic administration of the adjunct as a control to accurately identify an additional benefit of perineural administration. The challenge of how best to prolong block duration while minimising adverse events remains a topic of interest with further research required.

Infected pancreatic pseudocyst following severe dengue infection

Severe dengue infection is life threatening as it can result in fatal complications such as intractable bleeding from coagulopathy, multiorgan failure from shock and haemophagocytic syndrome. There have been case reports of atypical manifestation of severe dengue infection such as pancreatitis, Guillian-Barre's syndrome, perforated viscus and myocarditis. However, to our knowledge, pancreatic pseudocyst from dengue-related pancreatitis has never been reported in the literature. We hereby report a case of infected pancreatic pseudocyst in a patient with persistent pyrexia, abdominal pain and raised inflammatory markers 10 weeks from the onset of severe dengue infection. Endoscopic ultrasound (EUS) guided transluminal drainage of the infected pancreatic pseudocyst with lumen-apposing metallic stent (LAMS) was performed with good clinical and radiological outcome.

Endothelial-T cell crosstalk contributes to vascular injury in fatty liver disease

 

Cardiovascular complications are often the fundamental causes of death in non-alcoholic fatty liver disease (NAFLD) patients. While there are known systemic mediators in NAFLD that may induce vascular inflammation, the mechanism of endothelial dysfunction remain understudied. In this work, we harnessed the replicative potential of blood outgrowth endothelial cells (BOECs) to develop personalized cell lines from NAFLD patients and healthy controls. Our transcriptomic analysis showed that the top interactome network enriched in NAFLD BOECs comprised of several C-C and C-X-C chemokine ligands involved in immune cell chemotaxis. We previously reported T cell infiltration in mouse model of non-alcoholic steatohepatitis, and here, we confirmed enhanced endothelial chemokine signatures in arterial histological sections. To elucidate endothelial-immune crosstalk, we performed single-cell analysis on human peripheral blood mononuclear cells and found T cell intensification in NAFLD patients compared to healthy controls. Our immunoprofiling by flow cytometry further revealed that NAFLD patients possessed higher levels CD8+ memory cells. Functionally, T cells, instead of monocytes, adhered more pronouncedly to NAFLD BOECs. In evaluating the CXCL12-CXCR4 axis in chemotaxis, CXCR4 antagonist (AMD3100) substantially modulated the migration of patient-derived CD8+ T cells towards NAFLD BOECs, which was not observed in healthy endothelial-T cell chemotaxis coculture. Finally, we validated NAFLD-associated endothelial dysfunction by enumerating two folds more circulating endothelial cells, a biomarker of vascular injury, in the blood samples of NAFLD patients than healthy controls. Our work provides insights for translation to restore blood vessel health and potentially mitigate adverse vascular events in NAFLD.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Industrial Alignment Fund Pre-Positioning grant from the Agency for Science, Technology and Research, Singapore Endothelial-T cell crosstalk in NAFLD

Pulse-shape discrimination against low-energy Ar-39 beta decays in liquid argon with 4.5 tonne-years of DEAP-3600 data

The DEAP-3600 detector searches for the scintillation signal from dark matter particles scattering on a 3.3 tonne liquid argon target. The largest background comes from 39 Ar beta decays and is suppressed using pulse-shape discrimination (PSD). We use two types of PSD estimator: the prompt-fraction, which considers the fraction of the scintillation signal in a narrow and a wide time window around the event peak, and the log-likelihood-ratio, which compares the observed photon arrival times to a signal and a background model. We furthermore use two algorithms to determine the number of photons detected at a given time: (1) simply dividing the charge of each PMT pulse by the mean single-photoelectron charge, and (2) a likelihood analysis that considers the probability to detect a certain number of photons at a given time, based on a model for the scintillation pulse shape and for afterpulsing in the light detectors. The prompt-fraction performs approximately as well as the log-likelihood-ratio PSD algorithm if the photon detection times are not biased by detector effects. We explain this result using a model for the information carried by scintillation photons as a function of the time when they are detected.

668 The Consequences to Emergency Surgery During COVID19 Pandemic in a UK District General Hospital in The North East of England

Aim

COVID19 pandemic has significantly affected surgical services. We aim to review its effects on our theatre output and risk of encountering COVID 19 cases.

Method

Serial record of operations performed locally were reviewed from start of UK COVID19 pandemic lockdown on 23rd March 2020 to 13th July 2020 after it was lifted. A weekly average by month of operations and the percentage of COVID19 cases diagnosed within 30 days of the procedure were noted.

Results

733 operations performed through this period. In March, 33 operations/week performed, 88.4% emergency and 7% diagnosed with COVID19. April, 31 operations /week performed, 95.9% emergency and 10.6% diagnosed with COVID19. May 46 operations /week performed, 94.5% emergency and 3.3% diagnosed with COVID19. June 56 operations /week, 80.9% emergency and less than 0.01% diagnosed with COVID19. By July 80 operations/week, 59.4% emergency and none diagnosed with COVID 19. Since testing capacity increased, only 6 of the 27 operated were diagnosed with COVID19.

Conclusions

There was initial reduction to non-emergency workload. However, this has gradually shifted as protocols are in place improve public confidence to return for surgical treatment. Mandatory admission testing allows early identification and remains essential for planning of services and protecting the workforce.

Strong geometry dependence of the Casimir force between interpenetrated rectangular gratings

Quantum fluctuations give rise to Casimir forces between two parallel conducting plates, the magnitude of which increases monotonically as the separation decreases. By introducing nanoscale gratings to the surfaces, recent advances have opened opportunities for controlling the Casimir force in complex geometries. Here, we measure the Casimir force between two rectangular silicon gratings. Using an on-chip detection platform, we achieve accurate alignment between the two gratings so that they interpenetrate as the separation is reduced. Just before interpenetration occurs, the measured Casimir force is found to have a geometry dependence that is much stronger than previous experiments, with deviations from the proximity force approximation reaching a factor of ~500. After the gratings interpenetrate each other, the Casimir force becomes non-zero and independent of displacement. This work shows that the presence of gratings can strongly modify the Casimir force to control the interaction between nanomechanical components.

The geometry dependence of the Casimir force could enable applications in nanomechanical systems if the effects can be enhanced. Here, the authors demonstrate that the Casimir force between two interpenetrating nanoscale gratings can exceed the proximity force approximation by a factor of 500.

Behavioral testing in animal models of spinal cord injury

This review is based on a lecture presented at the Craig H. Neilsen Foundation sponsored Spinal Cord Injury Training Program at Ohio State University. We discuss the advantages and challenges of injury models in rodents and theory relation to various behavioral outcome measures. We offer strategies and advice on experimental design, behavioral testing, and on the challenges, one will encounter with animal testing. This review is designed to guide those entering the field of spinal cord injury and/or involved with in vivo animal testing.

The effect of Imatinib Mesylate in diffuse-type Tenosynovial Giant Cell Tumours on MR imaging and PET-CT

INTRODUCTION

Recurrence rates remain high after surgical treatment of diffuse-type Tenosynovial Giant Cell Tumour (TGCT). Imatinib Mesylate (IM) blocks Colony Stimulating Factor1 Receptor (CSF1R), the driver mechanism in TGCT. The aim of this study was to determine if IM reduces the tumour metabolic activity evaluated by PET-CT and to compare this response with the response seen on MR imaging.

MATERIALS AND METHODS

25 Consecutive patients treated with IM (off label use) for locally advanced (N = 12) or recurrent (N = 13) diffuse-type TGCT were included, 15 male and median age at diagnosis 39 (IQR 31-47) years. The knee was most frequently affected (n = 16; 64%). The effect of IM was assessed pre- and post-IM treatment by comparing MR scans and PET-CT. MR scans were assessed by Tumour Volume Score (TVS), an estimation of the tumour volume as a percentage of the total synovial cavity. PET-CT scans were evaluated based on maximum standardized uptake value (SUV-max). Partial response was defined as more than 50% tumour reduction with TVS and a decrease of at least 30% on SUV-max.

RESULTS

Median duration of IM treatment was 7.0 (IQR 4.2-11.5) months. Twenty patients (80%) discontinued IM treatment for poor response or intended surgery. Twenty patients experienced an adverse event grade 1-2, three patients grade 3 (creatinine increment, neutropenic sepsis, liver dysfunction). MR assessment of all joints showed 32% (6/19) partial response and 63% (12/19) stable disease, with a mean difference of 12% (P = 0.467; CI -22.4-46.0) TVS between pre- and post-IM and a significant mean difference of 23% (P = 0.021; CI 4.2-21.6) in all knee lesions. PET-CT, all joints, showed a significantly decreased mean difference of 5.3 (P = 0.004; CI 1.9-8.7) SUV-max between pre- and post-IM treatment (58% (11/19) partial response, 37% (7/19) stable disease). No correlation between MR imaging and PET-CT could be appreciated in 15 patients with complete radiological data.

CONCLUSION

This study confirms the moderate radiological response of IM in diffuse-type TGCT. PET-CT is a valuable additional diagnostic tool to quantify response to tyrosine kinase inhibitor treatment. Its value should be assessed further to validate its efficacy in the objective measurement of biological response in targeted systemic treatment of TGCT.

Acceptance of antiviral treatment and enhanced service model for pregnant patients carrying hepatitis B

INTRODUCTION

A service model was established for pregnant women with positive screening results for hepatitis B surface antigen (HBsAg) at Queen Mary Hospital in Hong Kong. All women were offered a blood test for hepatitis B virus (HBV) DNA level during the first antenatal visit. Women with HBV DNA levels of ≥200 000 IU/mL received counselling from hepatologists regarding treatment with antenatal tenofovir disoproxil fumarate (TDF) 300 mg daily.

METHODS

This retrospective review included women attending our antenatal clinic who exhibited positive HBsAg screening results from 15 May 2017 to 31 December 2019. The proportions of women with positive HBsAg, DNA test acceptance, hepatological review, and TDF acceptance during pregnancy were reviewed.

RESULTS

In total, 375 (2.9%) of 13 082 pregnant women had positive HBsAg screening results. Blood tests for HBV DNA and hepatological reviews were offered to 273 women who had not undergone hepatological review prior to pregnancy; the acceptance rate was 97.8%. Sixty (22.6%) pregnant women were hepatitis B carriers with high viral loads of ≥200 000 IU/mL. Among 58 women with high viral loads, 57 received antenatal counselling regarding TDF and 56 (96.6%) agreed to take the drug; 92.9% of these 56 women had commenced TDF at or before 32 weeks of gestation.

CONCLUSIONS

This study indicated broad acceptance of HBV DNA tests by pregnant women. Triage allowed early review and commencement of antiviral medication. This service model serves as a framework for enhanced antenatal service to prevent mother-to-child-transmission in public maternity units.

COVID-19: Initial experience of an international group of hand surgeons

The emergence of the COVID-19 pandemic has severely affected medical treatment protocols throughout the world. While the pandemic does not affect hand surgeons at first glance, they have a role to play. The purpose of this study was to describe the different measures that have been put in place in response to the COVID-19 pandemic by hand surgeons throughout the world. The survey comprised 47 surgeons working in 34 countries who responded to an online questionnaire. We found that the protocols varied in terms of visitors, health professionals in the operating room, patient waiting areas, wards and emergency rooms. Based on these preliminary findings, an international consensus on hand surgery practices for the current viral pandemic, and future ones, needs to be built rapidly.

International Nosocomial Infection Control Consortium (INICC) report, data summary of 45 countries for 2012-2017: Device-associated module

BACKGROUND

We report the results of International Nosocomial Infection Control Consortium (INICC) surveillance study from January 2012 to December 2017 in 523 intensive care units (ICUs) in 45 countries from Latin America, Europe, Eastern Mediterranean, Southeast Asia, and Western Pacific.

METHODS

During the 6-year study period, prospective data from 532,483 ICU patients hospitalized in 242 hospitals, for an aggregate of 2,197,304 patient days, were collected through the INICC Surveillance Online System (ISOS). The Centers for Disease Control and Prevention-National Healthcare Safety Network (CDC-NHSN) definitions for device-associated health care-associated infection (DA-HAI) were applied.

RESULTS

Although device use in INICC ICUs was similar to that reported from CDC-NHSN ICUs, DA-HAI rates were higher in the INICC ICUs: in the medical-surgical ICUs, the pooled central line-associated bloodstream infection rate was higher (5.05 vs 0.8 per 1,000 central line-days); the ventilator-associated pneumonia rate was also higher (14.1 vs 0.9 per 1,000 ventilator-days,), as well as the rate of catheter-associated urinary tract infection (5.1 vs 1.7 per 1,000 catheter-days). From blood cultures samples, frequencies of resistance, such as of Pseudomonas aeruginosa to piperacillin-tazobactam (33.0% vs 18.3%), were also higher.

CONCLUSIONS

Despite a significant trend toward the reduction in INICC ICUs, DA-HAI rates are still much higher compared with CDC-NHSN's ICUs representing the developed world. It is INICC's main goal to provide basic and cost-effective resources, through the INICC Surveillance Online System to tackle the burden of DA-HAIs effectively.

Effects of backpack and double pack loads on postural stability

Measurement of postural stability is crucial for identifying predictors of performance, determining the efficacy of physical training and rehabilitation techniques and evaluating and preventing injuries, particularly for heavy load carriage in hikers, mountain search and rescue personnel and soldiers. This study investigated the effect of load distribution on postural stability in an upright stance using backpack and double pack loads under conflicting or impaired somatosensory, visual and vestibular conditions. The sensory organisation tests were conducted on 20 young adults before and after a 10-min level walking exercise. Young adults' ability to use inputs from somatosensory and visual systems to maintain postural stability was significantly reduced following a 10-min walking exercise with a heavy backpack (30% of body weight), whereas no significant changes were observed for double pack carriage. Thus, the distribution of heavy loads to the front and back provides superior balance control compared with back-only loading. Practitioner summary: This study investigated the effects of heavy (30% of body weight) load distribution on postural stability after a 10-min walking exercise. Backpack carriage significantly reduced postural stability, whereas there was no significant effect under double pack loads. Distribution of heavy loads on the front-and-back is desirable for superior balance control.

Abstract GS1-08: Genomic characterisation of metastatic breast cancer

Rationale: while large efforts have been done to characterize early breast cancer, little is known about the genomic landscape of metastatic breast cancer. In the present study, we performed whole exome sequencing of 800 metastatic breast cancers, in order to identify new candidate targets and better stratify patients eligible for innovative therapies.

Patients and Methods: Patients were selected to present a metastatic breast cancer and to have received a biopsy in the context of precision medicine trials (SAFIR01, SAFIR02, PERMED, MOSCATO, SHIVA). Samples with &gt;30% cancer cells, and normal DNA, were sequenced using Hiseq and Novaseq. Drivers were identified using MutSigCV. Actionability of somatic genetic alterations was determined based on OncoKB. Decomposition of mutational signatures was performed using deconstructSigs. Prognostic value was assessed using a cox model. TCGA database was used as comparator to identify gene alterations enriched in metastatic samples.

Results: results presented in the current abstract are based on the first 629 patients analyzed.Sequencing was performed in 387 patients with HR+/Her2- breast cancer, 186 triple negative breast cancers, and 32 Her2-overexpressing breast cancers. only 9 patients received a pretreatment with a CDK4 inhibitor. 24 driver genes were significantly mutated. In patients with HR+/Her2- breast cancer, 11 genes were found more frequently mutated in the metastatic setting as compared to early stage breast cancer. This includes TP53 (29%), KMT2C (13%), NCOR1 (8%), NF1 (7%), RB1 (4%), C16orf3 (2%), FRG1 (6%), ESR1 (21%), RIC8A (4%), AKT1 (7%), PLSCR5 (2%). In addition, in the whole population, KRAS was found mutated in 3% of samples (G12A/C/R/V) while its frequency of mutation in early breast cancer is &lt;1%. No gene alteration was found enriched in metastatic Her2+++ and TNBC. Copy number alterations were compared between metastatic and early breast cancer. 18 amplicons were found more frequently in HR+/Her2- metastatic breast cancers as compared to eBC. Among the genes enriched in metastatic samples, mutations in RB1 or NF1 were associated with a poor outcome ( median OS 9 and 13 months respectively, p=0.0038 and 0.01 respectively). 73% of patients presenting HR+/Her2- mBC had an actionable alteration, as compared to 55% of patients presenting HR+/Her2- eBC (p&lt;0.01). Patients with HR+/Her2- mBC presented an enrichment of gene alterations in the MAPK/ERK pathway (37% vs 22%) and in the HRD pathway (22% vs 10%). When the analysis focuses on mTNBC; the proportion of patient presenting an actionable alteration was comparable to the eTNBC. 11 (6%) and 16 (9%) patients presented a somatic mutation or homozygous gene deletion on BRCA1 and PTEN respectively.

We further assessed the mutational signatures in order to better understand which mutational processes could drive cancer progression. Metastatic HR+/Her2- mBC presented an increase in APOBEC, S3 (HRD), S10 (POLE-associated signature), S17 signatures as compared to early HR+/Her2- BC.

Conclusion: the present study, based on 629 patients, identifies 11 driver gene alterations and four mutational processes enriched in HR+/Her2- metastatic breast cancers. Final results on 800 patients will be presented.

Citation Format: Andre F, Filleron T, Ng C, Bertucci F, Letourneau C, Jacquet A, Piscuoglio S, Jimenez M, Bachelot T. Genomic characterisation of metastatic breast cancer [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 GS1-08.