Ternary composites of poly(vinylidene fluoride-co-hexafluoropropylene) with silver nanowires and titanium dioxide nanoparticles as separator membranes for lithium-ion batteries

In the realm of polymer composites, there is growing interest in the use of more than one filler for achieving multifunctional properties. In this work, a composite separator membrane has been developed for lithium-ion battery application, by incorporating conductive silver nanowires (AgNWs) and titanium dioxide (TiO2) nanoparticles into a poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) polymer matrix. The composite membranes were manufactured by solvent casting and thermally induced phase separation, with total filler content varying up to 10 wt%. The ternary composites composites present improved mechanical characteristics, ionic conductivity and lithium transfer number compared to the neat polymer matrix. On the other hand, the filler type and content within the composite has little bearing on the morphology, polymer phase, or thermal stability. Once applied as a separator in lithium-ion batteries, the highest discharge capacity value was obtained for the 5 wt% AgNWs/5 wt% TiO2/PVDF-HFP membrane at different C-rates, benefiting from the synergetic effect from both fillers. This work demonstrates that higher battery performance can be achieved for next-generation lithium-ion batteries by using separator membranes based on ternary composites.

Initial Report of Boswellia Serrata for Management of Cerebral Radiation Necrosis after Stereotactic Radiosurgery for Brain Metastases

PURPOSE/OBJECTIVE(S)

Radiation necrosis (RN) is a concerning late toxicity after radiation therapy (RT) for brain metastases. Oral corticosteroids are the mainstay of management; however, they are not optimal for long-term use given multiple side effects and drug interactions, particularly with the emergence of immunotherapy for several cancers. Boswellia serrata (BS) is an over-the-counter supplement used for its anti-inflammatory properties and has been recently shown to reduce cerebral edema after brain RT. We evaluated the response rates with BS in a series of patients with brain metastases treated with stereotactic radiosurgery (SRS) who developed RN.

MATERIALS/METHODS

We included patients who developed RN after SRS for brain metastases at our institution from 2020-2022 and were treated with BS. Patients were prescribed over the counter BS 4.2-4.5g daily in divided doses. Follow-up MRI imaging was obtained every 2-3 months after starting BS. Response was assessed using Response Assessment in Neuro-Oncology (RANO) criteria. Primary endpoint was ≥25% decrease in edema volume on T2-FLAIR MRI from baseline. Patients were censored if they had tumor progression or repeat RT to necrotic area, or death. Kaplan-Meier curves were used for survival estimates.

RESULTS

A total of 50 patients received BS for Grade 1-3 CTCAE v5.0 RN (G1 = 11, G2 = 36, and G3 = 3). Median age was 62.8 years (range 36.9 - 50) and median RT dose was 24 Gy in 3 fractions. Median time to RN after SRS was 10 months(m). Median follow-up after starting BS was 6m and 40 patients had at least 1 follow up MRI available to evaluate response. The best response was complete response (CR) in 15% patients and partial response (PR) in 40% while 35% had stable disease (SD) and 10% had progressive disease. Median time to CR was 9m (6-12m) and PR was 6m (3-12m). Percentage of patients who had any response (CR or PR) at 3, 6, 9 and 12 months was 25%, 60%, 43% and 50%, respectively. 56% patients had symptomatic RN, of which 35.7% had improvement in symptoms with BS alone, while 64% required steroid use. Overall, median duration of response in patients with CR, PR or SD was 7.5m(range 2-31m). Salvage treatment for RN was steroids (33), surgery (4), Bevacizumab (5) or hyperbaric oxygen therapy (1). No patients had any CTCAE grade 3 or higher toxicities. 3 patients (6%) had any side-effects all of whom had Grade 1-2 gastrointestinal intolerance or diarrhea. 2 patients stopped treatment due to enrolment on an immunotherapy clinical trial. Overall, 39 patients remained on BS at last follow-up or death.

CONCLUSION

We observed >50% response rates with use of BS in our cohort of patients with Grade 1-3 RN after SRS. More than 1/3rd patients with symptomatic RN were able to avoid long-term steroid use. BS is an easily available over-the-counter drug that appears to be a safe and promising treatment option for RN, and can potentially decrease steroid dependence in these patients, reducing the risk of several side-effects. Further prospective studies to compare Boswellia with placebo is warranted.

Safety and Efficacy of Stereotactic Radiosurgery with Concurrent Targeted Systemic Therapy for Brain Metastases

PURPOSE/OBJECTIVE(S)

Data describing the safety and efficacy of central nervous system (CNS)-active targeted systemic therapies in combination with stereotactic radiosurgery (SRS, 1 fraction) and/or radiotherapy (SRT, 3-5 fractions) for brain metastases are emerging but limited. We report rates of local and intracranial failure and radiation necrosis in patients receiving CNS-active targeted systemic therapy and SRS/SRT.

MATERIALS/METHODS

We retrospectively identified patients with intact brain metastases at two institutions from 2009-2022 who were treated with SRS/SRT and CNS-active targeted systemic therapy in any sequence. Patients were followed for a minimum of 3 months after SRS/SRT with brain MRI. Patients typically stopped the targeted agent 2-4 days prior to radiation and resumed 2-4 days after. Targeted therapies included inhibitors of ALK/ROS1 (Alectinib, Ceritinib, Crizotinib, Lorlatinib), EGFR (Afatinib, Erlotinib, Gefitinib, Osimertinib), BRAF (Dabrafenib, Encorafenib, Vemurafenib), MEK (Binimetinib, Trametinib), CDK 4/6 (Abemaciclib, Palbociclib, Ribociclib), HER2 (Afatinib, Lapatinib, Neratinib, Pertuzumab, Trastuzumab, T-DM1, T-DXd, Tucatinib), KRAS (Adagrasib and Sotorasib), PARP (Niraparib, Olaparib), VEGF(R) (Axitinib, Bevacizumab, Ramucirumab), and less-selective tyrosine (receptor) kinase inhibitors (Bosutinib, Brigatinib, Entrectinib, Lenvatinib, Pazopanib, Sorafenib, Sunitinib). Local failure (LF) and radiation necrosis were determined radiographically with clinical impression (grade 2 (symptomatic) or higher (G2+)) and compared between different systemic agents.

RESULTS

The study included 95 patients with 310 metastases (SRS 246, SRT 64 metastases). Most common primary histologies were non-small cell lung cancer (36% 34/95), breast cancer (28% 27/95), and melanoma (16% 15/95). Overall survival at 1 and 2 years was 80% (76/95) and 55% (52/95), respectively. Median follow-up was 16.6 (range 3-91) months. Median tumor size was 7mm (range 1-75mm). Median number of brain metastases per patient was 2.5 (range 1-12). The G2+ radiation necrosis rate was 5.8% (18/310) while the LF rate was 9.7% (30/310) per metastasis. There was no significant difference in G2+ radiation necrosis by class of targeted therapy. Sixty-two percent (59/95) of patients experienced distant intracranial failure. Median intracranial progression free survival (PFS) was 8.0 (range 0.4-61.4) months.

CONCLUSION

Although heterogeneous, patients treated with SRS/SRT and ongoing CNS-active targeted systemic therapies have on average >6 month intracranial PFS and little evidence of significant toxicity. We observed <6% G2+ radiation necrosis for this cohort, and no particular class of agent was associated with a significantly higher rate of G2+ radiation necrosis.

Neurologic Events and Outcomes in Patients Receiving Proton and Photon Reirradiation for High Grade Non-Codeleted Gliomas

PURPOSE/OBJECTIVE(S)

Patients undergoing reirradiation (ReRT) for high grade glioma are at risk for tumor progression, pseudoprogression, and radiation necrosis. We investigated factors associated with neurologic events and disease control after re-irradiation with protons and photons at a single academic center.

MATERIALS/METHODS

We reviewed records and MRIs of patients receiving scanning beam proton (since center opening in 2016) and photon (since 2015) reirradiation in ≥10 fractions for grade 3 anaplastic astrocytoma (AA) and grade 4 glioblastoma (GBM), excluding 1p19q co-deleted oligodendrogliomas and extensive multifocal/leptomeningeal disease. The primary endpoint was time from ReRT to ≥ grade 2 pseudoprogression or radiation necrosis (PsP/RN, grade 2: moderate symptoms requiring outpatient steroids/bevacizumab, grade 3: severe symptoms leading to admission or surgical intervention). Dose was converted to EQD2 using a/b = 3. Cox proportional hazards model was used to calculate survival and time to PsP/RN.

RESULTS

A total of 53 patients were included (26 protons, 27 photons, median KPS 80). Patients receiving protons had more favorable features. Compared to the photons, the proton group was younger (48 vs. 58) and more likely to have AA (46% vs. 22%) and resection within 3 months (42% vs 26%). The proton group also had a longer interval from prior RT (57 vs. 39 months) and were less likely to receive bevacizumab at reRT (15% vs. 59%). CTV was 130 cc for protons vs 99 cc for photons, and most had active disease at time of ReRT identified on planning MRI (76% protons, 85% photons). Median OS was 10.5 months (14.1 months protons, 8.1 months photons), with time from initial RT the only significant factor on multivariate analysis. Median PFS was 9.4 months (9.8 months protons, 6.2 months photons). 9 patients (18%) had ≥ grade 3 PsP/RN (8 proton, 1 photon) and 21 patients (41%) had ≥ grade 2 PsP/RN (16 proton, 5 photon). Grade 3 events included 1 seizure (photon group), 1 hemorrhage, 1 thalamic stroke, 1 shunt placement, 1 re-resection, and PSP4 4 PsP/RN requiring admission. Protons were associated shorter time to ≥ grade 2 PsP/RN (4 months vs. not reached, p = 0.027). When accounting for bevacizumab use at time of reRT, the association between protons and PsP/RN lost significance but there remained a trend (grade 2, p = 0.095, HR 2.4; grade 3, p = 0.105, HR 5.8). CTV, MGMT status, EQD2, and interval from prior RT were not associated with PsP/RN.

CONCLUSION

High grade neurologic events were common in patients with predominantly active, unresected high grade gliomas receiving ReRT. Though ascertainment and survival bias are significant limitations, pseudoprogression and necrosis appeared to be more prominent in patients receiving protons. These results contribute to ongoing efforts to both optimize ReRT for high grade glioma and investigate biologic effects of proton therapy.

396 A Rare Encounter of “Forgotten Disease”

With the advent and prompt use of antibiotics after throat infections, the rare entity of Necrobacillosis has almost disappeared in clinical practice. Here we present a case of a fit and well 27-year-old lady who was brought into A&E with septic shock, DIC and MODS after initial diagnosis of a sore throat 4 days ago which was treated by oral antibiotics. She was found to have bilateral patchy consolidations which later became necrotic cavities, empyema thoracis, peritonitis and abscess cavities in abdomen with evolving splenic abscess, prolonged QT and ectopics and type 2 respiratory failure. She was resuscitated, intubated, and transferred to the ICU. With an isolate of Fusobacterium necrophorum from blood culture Meropenem, clindamycin and metronidazole were started. However, over the next few days of treatment, lack of clinical response prompted antibiotics changing, and surgical drainage of abscesses in chest and abdomen. Eventually after a considerable period of abdominal abscess drainage and about 3 weeks of metronidazole and other antibiotics followed by Piperacillin and tazobactam for another 3 weeks the patient recovered from sepsis and was stepped down to ward. This case though rare is a good example of the benefits of surgical drainage and prolonged antibiotics for septic patients with collections. A rapid weaning only results in re-collection and clinical deterioration, or recurrent collection as happened to this patient. This is a rare case of Lemierre's syndrome which depicts the surgical difficulties faced due to recurrent abscess cavities formed in this condition.

Risk assessment of consumer spray products using in vitro lung surfactant function inhibition, exposure modelling and chemical analysis

Consumer spray products release aerosols that can potentially be inhaled and reach the deep parts of the lungs. A thin layer of liquid, containing a mixture of proteins and lipids known as lung surfactant, coats the alveoli. Inhibition of lung surfactant function can lead to acute loss of lung function. We focused on two groups of spray products; 8 cleaning and 13 impregnation products, and in the context of risk assessment, used an in vitro method for assessing inhibition of lung surfactant function. Original spray-cans were used to generate aerosols to measure aerodynamic particle size distribution. We recreated a real-life exposure scenario to estimate the alveolar deposited dose. Most impregnation products inhibited lung surfactant function at the lowest aerosolization rate, whereas only two cleaning products inhibited function at the highest rates. We used inhibitory dose and estimated alveolar deposition to calculate the margin of safety (MoS). The MoS for the inhibitory products was ≤1 for the impregnation products, while much larger for the cleaning products (>880). This risk assessment focused on the risk of lung surfactant function disruption and provides knowledge on an endpoint of lung toxicity that is not investigated by the currently available OECD test guidelines.

Socio-economic variations in the clinical presentation, etiology and outcome of infective endocarditis in the ESC-EORP EURO-ENDO (European Infective Endocarditis) registry: a prospective cohort study

Background

Infective endocarditis (IE) is a life threatening disease associated with high mortality and morbidity worldwide. We sought to determine how socio-economic factors may influence variations in epidemiology, clinical presentation, investigation and management (and their consequence upon clinical outcomes) in a large international multi-centre registry.

Methods

The ESC-EORPEURO-ENDO registry comprises a prospective cohort of 3116 adult patients admitted to 156 hospitals in 40 countries with IE between January 2016 and March 2018. We analysed the complete dataset to assess potentially important determinants of variation according to World Bank economic stratification (high income (Group 1) [73.8%]; upper-middle income (Group 2) [17.1%]; lower-middle income (Group 3)[9.1%]).

Results

Patients in Group 3 were younger (median age [IQR]: Group 1 - 66 [54–75] years; Group 2 - 57 [40–68] years; Group 3 - 33 [26–43] years; p&lt;0.001) with a higher prevalence of smoking, intravenous drug use and human immunodeficiency virus (HIV) infection (all p&lt;0.001). Group 3 patients with IE presented later (median [IQR) days since symptom onset: Group 1 - 12 [3–35]; Group 2 - 20 [6–51]; Group 3 - 31 [12–62]; p&lt;0.001) and were more likely to develop congestive heart failure (13.6%; 11.3%; and 22.6%, respectively; p&lt;0.001), septic shock (8.3%; 11.1%; 13.4%; p=0.007), and persistent fever for greater than 7 days (9.6%; 14.4%; 27.9%; p&lt;0.001) following hospital admission. Surgery was performed less frequently in Group 3 (75.4%, 76.8% and 51.3% in Groups 1, 2 and 3, respectively; p&lt;0.001) and mortality was highest in the poorest countries (14.6%; 23.6% and 23.7%, respectively; p&lt;0.001).

Conclusion

Socio-economic factors influence the clinical profile of patients presenting with IE across the world. Despite being younger, patients from the poorest countries presented with more frequent complications and higher mortality associated with delayed diagnosis and less frequent use of surgery.

Funding Acknowledgement

Type of funding sources: None.

Peak atrial longitudinal strain predicts exercise tolerance in heart failure with preserved ejection fraction

Purpose

The present study i) determined left atrial (LA) and left ventricular (LV) strains at rest and in response to exercise in patients with heart failure with preserved ejection fraction (HFpEF) and heart failure with reduced ejection fraction (HFrEF), and ii) assessed the relationship between LA and LV strains and exercise tolerance.

Methods

Forty HFpEF patients (age 59±7 yrs; 25 females), 40 stable HFrEF patients (age 57+6 yrs, 15 females) and 20 controls (age 56+6 yrs, 13 females) underwent baseline clinical and biochemical assessment, resting and exercise stress transthoracic echocardiography using modified Bruce protocol. Speckle-tracking echocardiography was performed to define peak atrial longitudinal strain (PALS) and left ventricular global longitudinal strain (LVGLS). LA stiffness index and LV stiffness index were also derived.

Results

Compared to healthy controls, HFpEF and HFrEF showed significantly lower PALS at rest (34.03±1.85 vs. 23.06±4.69 vs. 11.51±1.44%, p&lt;0.01) and after exercise (34.41±1.24 vs. 18.48±3.51 vs 10.47±1.49, p&lt;0.01 for both). In response to exercise, the PALS significantly reduced in HFpEF by 26%, but only 8% in HFrEF and remained unchanged in controls. LA stiffness index was higher in HFpEF and HFrEF compared to healthy controls at rest (0.57±0.22 vs. 1.19±0.63 vs. 0.27±0.06, p&lt;0.01) and in response to exercise (0.83±0.46 vs. 1.37±0.63 vs. 0.33±0.04, p&lt;0.01). Compared to healthy controls, HFpEF and HFrEF demonstrated significantly lower LVGLS at rest (−20.27±0.98 vs. −15.89±2.72 vs.-11.14±3.40%, p&lt;0.01) and after exercise (−19.9±0.8 vs.-15.5±3.18 vs.-11.01±2.6%, p&lt;0.01). LV stiffness index was significantly higher in HFpEF and HFrEF compared to healthy controls at rest (0.16±0.05 vs. 0.14±0.07 vs. 0.11±0.02, p&lt;0.01) and in response to exercise (0.18±0.07 vs. 0.15±0.06 vs. 0.13±0.02, p&lt;0.01). Exercise tolerance i.e. exercise duration was significantly lower by 28% and 30% in HFpEF and HFrEF compared with controls (363±152 vs. 352±91 vs. 505±42, p&lt;0.01). There was a significant relationship between peak atrial longitudinal strain and exercise tolerance in HFpEF (r=0.32, p=0.04).There was no significant relationship between exercise tolerance and LVGLS (r=0.058, p=0.72), LA stiffness (r=−0.17, p=0.3), LV stiffness (r=0.88, p=.59). There was no significant relationship between exercise tolerance and PALS (r=0.021, p=0.89) or LVGLS (r=0.12, p=0.48) in HFrEF.

Conclusion

HFpEF and HFrEF are associated with reduced left atrial and left ventricular strains and increased arial and ventricular stiffness.Peak atrial longitudinal strain is a significant determinant of exercise tolerance in HFpEF but not in HFrEF.

Funding Acknowledgement

Type of funding sources: None.

Work From Home, Mental Health and Employee Needs: A pilot study in selected information technology organizations in India

Introduction: The Coronavirus (COVID-19) pandemic has impacted the economy and has resulted in changes to the working arrangements of employees who are based at home and may continue to work from home (WFH). Organizations are expected to develop an inclusive policy for their employees to promote mental health whilst working from home. The aim of this study was to document the impact of WFH on mental health and determine the expectations of employees from their organizations regarding occupational health policy. Methodology: A cross-sectional study was conducted on the impact of work from home on mental health and to document the mental health support needs of employees. Google form was floated through social media platform to receive the responses. A total of 74 responses were received. Descriptive analysis was conducted using Microsoft Excel, while qualitative answers were manually analysed. Results: About 67% employees (n=45) mentioned that their workload has increased significantly during work from home. Thirty five percent (n=26) felt lonely and lost and 47% (n= 34) felt disconnected from the real world, indicating the mental health impact of work from home. Fifty three percent employees (n=40) mentioned that there were no efforts made by their organization to reduce the mental health impact of work from home. Conclusion: The results of this study indicate that there is an urgent need to create a comprehensive occupational health and safety policy inclusive of strategies to improve mental health by the organizations in light of “work from home” as a “new-normal”.

Characterizing genetic intra-tumor heterogeneity across 2,658 human cancer genomes

Intra-tumor heterogeneity (ITH) is a mechanism of therapeutic resistance and therefore an important clinical challenge. However, the extent, origin, and drivers of ITH across cancer types are poorly understood. To address this, we extensively characterize ITH across whole-genome sequences of 2,658 cancer samples spanning 38 cancer types. Nearly all informative samples (95.1%) contain evidence of distinct subclonal expansions with frequent branching relationships between subclones. We observe positive selection of subclonal driver mutations across most cancer types and identify cancer type-specific subclonal patterns of driver gene mutations, fusions, structural variants, and copy number alterations as well as dynamic changes in mutational processes between subclonal expansions. Our results underline the importance of ITH and its drivers in tumor evolution and provide a pan-cancer resource of comprehensively annotated subclonal events from whole-genome sequencing data.

Brain and Lung Imaging Correlation in Patients with COVID-19: Could the Severity of Lung Disease Reflect the Prevalence of Acute Abnormalities on Neuroimaging? A Global Multicenter Observational Study

PURPOSE

Our aim was to study the association between abnormal findings on chest and brain imaging in patients with coronavirus disease 2019 (COVID-19) and neurologic symptoms.

MATERIALS AND METHODS

In this retrospective, international multicenter study, we reviewed the electronic medical records and imaging of hospitalized patients with COVID-19 from March 3, 2020, to June 25, 2020. Our inclusion criteria were patients diagnosed with Severe Acute Respiratory Syndrome coronavirus 2 (SARS-CoV-2) infection with acute neurologic manifestations and available chest CT and brain imaging. The 5 lobes of the lungs were individually scored on a scale of 0-5 (0 corresponded to no involvement and 5 corresponded to >75% involvement). A CT lung severity score was determined as the sum of lung involvement, ranging from 0 (no involvement) to 25 (maximum involvement).

RESULTS

A total of 135 patients met the inclusion criteria with 132 brain CT, 36 brain MR imaging, 7 MRA of the head and neck, and 135 chest CT studies. Compared with 86 (64%) patients without acute abnormal findings on neuroimaging, 49 (36%) patients with these findings had a significantly higher mean CT lung severity score (9.9 versus 5.8, P < .001). These patients were more likely to present with ischemic stroke (40 [82%] versus 11 [13%], P < .0001) and were more likely to have either ground-glass opacities or consolidation (46 [94%] versus 73 [84%], P = .01) in the lungs. A threshold of the CT lung severity score of >8 was found to be 74% sensitive and 65% specific for acute abnormal findings on neuroimaging. The neuroimaging hallmarks of these patients were acute ischemic infarct (28%), intracranial hemorrhage (10%) including microhemorrhages (19%), and leukoencephalopathy with and/or without restricted diffusion (11%). The predominant CT chest findings were peripheral ground-glass opacities with or without consolidation.

CONCLUSIONS

The CT lung disease severity score may be predictive of acute abnormalities on neuroimaging in patients with COVID-19 with neurologic manifestations. This can be used as a predictive tool in patient management to improve clinical outcome.

Allele-specific open chromatin in human iPSC neurons elucidates functional disease variants

Most neuropsychiatric disease risk variants are in noncoding sequences and lack functional interpretation. Because regulatory sequences often reside in open chromatin, we reasoned that neuropsychiatric disease risk variants may affect chromatin accessibility during neurodevelopment. Using human induced pluripotent stem cell (iPSC)-derived neurons that model developing brains, we identified thousands of genetic variants exhibiting allele-specific open chromatin (ASoC). These neuronal ASoCs were partially driven by altered transcription factor binding, overrepresented in brain gene enhancers and expression quantitative trait loci, and frequently associated with distal genes through chromatin contacts. ASoCs were enriched for genetic variants associated with brain disorders, enabling identification of functional schizophrenia risk variants and their cis-target genes. This study highlights ASoC as a functional mechanism of noncoding neuropsychiatric risk variants, providing a powerful framework for identifying disease causal variants and genes.

Imaging-Genomic Study of Head and Neck Squamous Cell Carcinoma: Associations Between Radiomic Phenotypes and Genomic Mechanisms via Integration of The Cancer Genome Atlas and The Cancer Imaging Archive

PURPOSE

Recent data suggest that imaging radiomic features of a tumor could be indicative of important genomic biomarkers. Understanding the relationship between radiomic and genomic features is important for basic cancer research and future patient care. We performed a comprehensive study to discover the imaginggenomic associations in head and neck squamous cell carcinoma (HNSCC) and explore the potential of predicting tumor genomic alternations using radiomic features.

METHODS

Our retrospective study integrated whole-genome multiomics data from The Cancer Genome Atlas with matched computed tomography imaging data from The Cancer Imaging Archive for the same set of 126 patients with HNSCC. Linear regression and gene set enrichment analysis were used to identify statistically significant associations between radiomic imaging and genomic features. Random forest classifier was used to predict the status of two key HNSCC molecular biomarkers, human papillomavirus and disruptive TP53 mutation, on the basis of radiomic features.

RESULTS

Widespread and statistically significant associations were discovered between genomic features (including microRNA expression, somatic mutations, and transcriptional activity, copy number variations, and promoter region DNA methylation changes of pathways) and radiomic features characterizing the size, shape, and texture of tumor. Prediction of human papillomavirus and TP53 mutation status using radiomic features achieved areas under the receiver operating characteristic curve of 0.71 and 0.641, respectively.

CONCLUSION

Our exploratory study suggests that radiomic features are associated with genomic characteristics at multiple molecular layers in HNSCC and provides justification for continued development of radiomics as biomarkers for relevant genomic alterations in HNSCC.

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.

Neoadjuvant radiotherapy in rectal cancer - less is more?

AIM

There is significant international variation in the use of neoadjuvant radiation prior to total mesorectal excision. The MERCURY group advocate selective neoadjuvant chemoradiotherapy (CRT). We have performed a retrospective, single-centre study of patients treated with CRT, where only the circumferential resection margin is threatened, with the aim of identifying whether a more selective approach to CRT provides acceptable local relapse rates (LRRs).

METHOD

All consecutive patients who underwent radical surgery for rectal adenocarcinoma over a 5-year period (2007-2012) in the Oxford University Trust were considered. Electronic hospital systems were reviewed to obtain patient and tumour demographics, treatment and follow-up information. All patients were classified into risk categories according to National Institute for Health and Care Excellence guidance. Data were analysed using Microsoft Excel and R.

RESULTS

Two hundred and seventy-two patients were identified: 123, 89 and 60 in the high-, intermediate- and low-risk categories, respectively. Seventy-nine per cent of those in the high-risk group, 6% in the intermediate and 5% in the low-risk group underwent CRT. The overall 5-year LRR and distant recurrence rate (DRR) were 5.2% and 17.8%, respectively. The 5-year LRR for those who went straight to surgery was 2.0% and for those who had neoadjuvant CRT it was 7.4%. The DRR for these two groups was 8.5% and 18.9%, respectively.

CONCLUSION

Our series demonstrates that the use of CRT only in margin-threatening tumours, results in an exceptionally low LRR for those without margin-threatening disease. In routine clinical care, this strategy can minimize the significant morbidity of multimodal treatment and allow earlier introduction of systemic therapy to minimize distant recurrence.

Pan-cancer analysis of whole genomes

Cancer is driven by genetic change, and the advent of massively parallel sequencing has enabled systematic documentation of this variation at the whole-genome scale1-3. Here we report the integrative analysis of 2,658 whole-cancer genomes and their matching normal tissues across 38 tumour types from the Pan-Cancer Analysis of Whole Genomes (PCAWG) Consortium of the International Cancer Genome Consortium (ICGC) and The Cancer Genome Atlas (TCGA). We describe the generation of the PCAWG resource, facilitated by international data sharing using compute clouds. On average, cancer genomes contained 4-5 driver mutations when combining coding and non-coding genomic elements; however, in around 5% of cases no drivers were identified, suggesting that cancer driver discovery is not yet complete. Chromothripsis, in which many clustered structural variants arise in a single catastrophic event, is frequently an early event in tumour evolution; in acral melanoma, for example, these events precede most somatic point mutations and affect several cancer-associated genes simultaneously. Cancers with abnormal telomere maintenance often originate from tissues with low replicative activity and show several mechanisms of preventing telomere attrition to critical levels. Common and rare germline variants affect patterns of somatic mutation, including point mutations, structural variants and somatic retrotransposition. A collection of papers from the PCAWG Consortium describes non-coding mutations that drive cancer beyond those in the TERT promoter4; identifies new signatures of mutational processes that cause base substitutions, small insertions and deletions and structural variation5,6; analyses timings and patterns of tumour evolution7; describes the diverse transcriptional consequences of somatic mutation on splicing, expression levels, fusion genes and promoter activity8,9; and evaluates a range of more-specialized features of cancer genomes8,10-18.

The evolutionary history of 2,658 cancers

Cancer develops through a process of somatic evolution1,2. Sequencing data from a single biopsy represent a snapshot of this process that can reveal the timing of specific genomic aberrations and the changing influence of mutational processes3. Here, by whole-genome sequencing analysis of 2,658 cancers as part of the Pan-Cancer Analysis of Whole Genomes (PCAWG) Consortium of the International Cancer Genome Consortium (ICGC) and The Cancer Genome Atlas (TCGA)4, we reconstruct the life history and evolution of mutational processes and driver mutation sequences of 38 types of cancer. Early oncogenesis is characterized by mutations in a constrained set of driver genes, and specific copy number gains, such as trisomy 7 in glioblastoma and isochromosome 17q in medulloblastoma. The mutational spectrum changes significantly throughout tumour evolution in 40% of samples. A nearly fourfold diversification of driver genes and increased genomic instability are features of later stages. Copy number alterations often occur in mitotic crises, and lead to simultaneous gains of chromosomal segments. Timing analyses suggest that driver mutations often precede diagnosis by many years, if not decades. Together, these results determine the evolutionary trajectories of cancer, and highlight opportunities for early cancer detection.

R0 Resection Margin, A New Quality Measure in the Era of National Bowel Screening?

Aims To determine the completeness of polyp resection (i.e. achieving an R0 margin) and its relation with Endoscopists, histopathologist, size, location and technique of polypectomy in an NSS cohort. The definition of R0 margin is complete macroscopic resection with a negative microscopic margin at polypectomy. Method NCCS (National Colon Cancer Screening) colonoscopies are offered to bowel cancer screening patients after a positive faecal immunochemical test (FIT) test in a Joint Advisory Group (JAG) accredited Gastrointestinal Endoscopy centre. We histologically evaluated the polyp margins for complete resection, which was defined as the absence of adenomatous or hyperplastic tissue in the resected polyp margins in a cohort of faecal immunochemical test positive patients. Results A total of 186 consecutive NCCS colonoscopies out of a total of 542 performed between 2013 and 2017 were included in this study. Of the polyps excised 152(27%) had a R0 margin histologically, and 30(5%) had involvement of the margin. Surprisingly in 373(67%) of polyps pathologists were unable to assess the margin. Conclusion Achieving an R0 margin should be a key performance indicator for endoscopists performing polypectomy. At the same time more studies on polyp margins are recommended.

EAU-ESMO consensus statements on the management of advanced and variant bladder cancer-an international collaborative multi-stakeholder effort: under the auspices of the EAU and ESMO Guidelines Committees†

BACKGROUND

Although guidelines exist for advanced and variant bladder cancer management, evidence is limited/conflicting in some areas and the optimal approach remains controversial.

OBJECTIVE

To bring together a large multidisciplinary group of experts to develop consensus statements on controversial topics in bladder cancer management.

DESIGN

A steering committee compiled proposed statements regarding advanced and variant bladder cancer management which were assessed by 113 experts in a Delphi survey. Statements not reaching consensus were reviewed; those prioritised were revised by a panel of 45 experts before voting during a consensus conference.

SETTING

Online Delphi survey and consensus conference.

PARTICIPANTS

The European Association of Urology (EAU), the European Society for Medical Oncology (ESMO), experts in bladder cancer management.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Statements were ranked by experts according to their level of agreement: 1-3 (disagree), 4-6 (equivocal), 7-9 (agree). A priori (level 1) consensus was defined as ≥70% agreement and ≤15% disagreement, or vice versa. In the Delphi survey, a second analysis was restricted to stakeholder group(s) considered to have adequate expertise relating to each statement (to achieve level 2 consensus).

RESULTS AND LIMITATIONS

Overall, 116 statements were included in the Delphi survey. Of these, 33 (28%) statements achieved level 1 consensus and 49 (42%) statements achieved level 1 or 2 consensus. At the consensus conference, 22 of 27 (81%) statements achieved consensus. These consensus statements provide further guidance across a broad range of topics, including the management of variant histologies, the role/limitations of prognostic biomarkers in clinical decision making, bladder preservation strategies, modern radiotherapy techniques, the management of oligometastatic disease and the evolving role of checkpoint inhibitor therapy in metastatic disease.

CONCLUSIONS

These consensus statements provide further guidance on controversial topics in advanced and variant bladder cancer management until a time where further evidence is available to guide our approach.

High Performance Bi-2212 Round Wires Made with Recent Powders

Multifilamentary Bi₂Sr₂CaCu₂O_x (Bi-2212) wire made by the powder-in-tube technique is the only high temperature superconductor made in the round shape preferred by magnet builders. The critical current density (J _C ) of Bi-2212 round wire was improved significantly by the development of overpressure heat treatment in the past few years. Bi-2212 wire is commercially available in multiple architectures and kilometer-long pieces and a very promising conductor for very high field NMR and accelerator magnets. We studied the effects of precursor powder and heat treatment conditions on the superconducting properties and microstructure of recent Bi-2212 wires. Short samples of recent wire with optimized overpressure processing showed J _C (4.2 K, 15 T) = 6640 A/mm² and J _C (4.2 K, 30 T) = 4670 A/mm², which correspond to engineering critical current densities J _E (4.2 K, 15 T) = 1320 A/mm² and J _E (4.2 K, 30 T) = 930 A/mm².

Spectral and Structural Variations of Biomimetic Light-Harvesting Nanotubes

Bioinspired, self-assembled nanotubes have been investigated by low-temperature, polarization-resolved single-tube spectroscopy. These assemblies are based on zinc chlorin monomers and are considered as model systems that resemble the secondary structural elements in the natural light-harvesting systems of green (non)sulfur bacteria. Compared to the natural systems, the spectral parameters extracted from the single-nanotube spectra feature distributions with significantly smaller widths, which is ascribed to a tremendous reduction of structural heterogeneity in the artificial systems. Employing quantum chemical molecular modeling the spectra of individual nanotubes can be explained consistently only for a molecular packing model that is fundamentally different from those considered so far for the natural systems. Subsequent theoretical simulations reveal that the remaining spectral variations between single nanotubes can be traced back to small variations of the mutual orientations of the monomer transition dipole moments that are far beyond the resolving power of high-resolution electron microscopy imaging techniques.

Variations in antibiotic use across India: multi-centre study through Global Point Prevalence survey

The aim of the study was to assess antimicrobial prescribing patterns, and variation in practice, in India. A point prevalence survey (PPS) was conducted in October to December 2017 in 16 tertiary care hospitals across India. The survey included all inpatients receiving an antimicrobial on the day of PPS and collected data were analysed using a web-based application of the University of Antwerp. In all, 1750 patients were surveyed, of whom 1005 were receiving a total of 1578 antimicrobials. Among the antimicrobials prescribed, 26.87% were for community-acquired infections; 19.20% for hospital-acquired infections; 17.24% for medical prophylaxis; 28.70% for surgical prophylaxis; and 7.99% for other or undetermined reasons. Antibiotic prescribing quality indicators, such as reason in notes and post-prescription review score, were low. This PPS showed widespread antibiotic usage, underlining the need for antibiotic stewardship to promote evidence-based practice.

Abstract P2-06-14: The role of SLC7A5 (LAT1) in endocrine therapy-resistant breast cancer

Endocrine therapies are commonly used to treat estrogen receptor-positive (ER+) breast cancers, which comprise 70% of all new breast cancer cases. Unfortunately, emergence of resistance to these therapies presents a major clinical challenge. Cancer cells can adapt to the dysregulation of cellular metabolism induced by endocrine therapy in order to evade cell death.Central to this adaptation is the scavenging of free-formed amino acids from the tumor microenvironment. For example, we found 109 solute carrier (SLC) mRNAs to be differentially expressed between endocrine-sensitive and resistant cells. We began our mechanistic studies of these genes with SLC family 7 member 5 (SLC7A5 or LAT1). SLC7A5 is a key component of a transmembrane transporter, which can complex with CD98 and increase the uptake of large, neutral amino acids (such as leucine or tyrosine).

We used a panel of endocrine therapy-resistant (LCC9) and sensitive (MCF7; LCC1) breast cancer cells. SLC7A5 expression was upregulated by estrogen in MCF7 and LCC1 cells; this induction was blocked by fulvestrant treatment. Basal expression of the SLC7A5 protein in the absence of estrogen was 2.75-fold higher in LCC9 cells compared with MCF7 cells; SLC7A5 mRNA expression was 71-fold higher. Fulvestrant treatment did not significantly alter SLC7A5 mRNA or protein expression in LCC9 cells. Inhibiting SLC7A5 function using either a pharmacological inhibitor (JPH203), or depleting expression using siRNA, led to significant suppression of LCC9 cell growth. Cell cycle analysis revealed that SLC7A5 depletion caused cells to accumulate in the G1-phase, with a concurrent reduction of cells in S-phase. In four publicly available datasets of ER+, tamoxifen treated breast cancer patients, high expression of SLC7A5 was significantly associated with poor relapse-free survival.

This study uncovers a novel adaptive mechanism in endocrine therapy-resistant breast cancer cells that is facilitated by increased expression of SLC7A5, which enables them to supplement their increased metabolic needs and promoting cell growth. Blocking the functions of SLC7A5, perhaps in conjunction with inhibition of autophagy, may therefore offer a new avenue of potential therapeutic intervention against endocrine therapy-resistant breast cancers.

Citation Format: Sevigny CM, Sengupta S, Luo Z, Jin L, Pearce D, Clarke R. The role of SLC7A5 (LAT1) in endocrine therapy-resistant 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 P2-06-14.

Abstract P5-04-17: Local network topology differences between early and late recurrence in ER+ breast cancers

Background: Late recurrence is characteristic of ER+ breast cancers. Despite an apparently effective adjuvant endocrine therapy, many breast cancers recur years after their initial endocrine treatment. Why some tumors recur early (&lt;3 years) and some recur later (&gt;5 years) is poorly understood. If systemic endocrine therapies killed all cells, recurrence would reflect only the appearance of new disease. Thus, we hypothesized that cells that survive and lie dormant may be driven, in part, by altered wiring of their cell death signaling. We, therefore, studied how cell death signaling is differentially wired in primary tumors that will recur early versus those that will recur later.

Method: Genes involved in apoptosis, autophagy, ferroptosis, necrosis, and pyroptosis were identified from KEGG to initiate network feature analysis of gene expression data from public and our first in-house gene expression dataset. Data were collected from ER+ breast cancer pre-endocrine treatment samples with up to 20 years follow-up. Publicly available datasets used were GSE6532, GSE2034, GSE7390, GSE17705, GSE12093, and TCGA. We applied our Knowledge-fused Differential Dependency Network (KDDN) analysis tool to the public datasets; KDDN has provided powerful new insights into signaling in breast and other cancers. Common gene-gene interactions (edges) predicted in at least two different datasets were extracted from all KDDN analyses results. To strengthen the relevance of these features, predicted network edges that represent known protein-protein interactions (PPI) were identified from the STRING database, and these edges were noted in the signaling graphs. Final network graphs were constructed using the common edges from all overlaid networks. We conducted IPA analysis on all nodes in the final network and selected those incorporating network hubs. We took a similar approach to our second in-house dataset, which we used for independent testing. Here, patients were included if their tumor exhibited an initial reduction in volume of at least 40% by four months in response to neo-adjuvant Letrozole. Patients were then classified into two groups during follow-up of up to 3.7 years: i) initial tumor size reduction followed by continued response (expected to recur late); ii) initial reduction followed by tumor regrowth (expected to recur early). KDDN analysis was performed on pretreatment samples from these two groups and a network created annotated with PPI information.

Results: MAPK8 and CYCS (Molecular Mechanisms of Cancer, p=1.58E-52), TNFRSF1A Neuroinflammation Signaling Pathway, p=1.26E-54), RELA, and NFKB1 (Colorectal Cancer Metastasis Signaling, p=7.94E-35), were identified as hubs. Hubs may be critical signaling components driving the differences between tumors that will become dormant and recur late. Connections between SLC25A6 and SQSTM1 (p = 0.008), BIRC2 and GABARAP (p = 0.021) in the early group, and AKT3 and IRS2 (p = 0.014) in the late group, were shared between the two final networks. With longer follow-up time on the second in-house dataset, we will better define the two groups and identify additional common phenotype specific gene-gene interactions.

Citation Format: Clarke R, Dixon M, Jin L, Pearce D, Turnbull A, Selli C, Hu R, Zwart A, Wang Y, Xuan J, Sengupta S, Sims A, Liu MC. Local network topology differences between early and late recurrence in ER+ breast cancers [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 P5-04-17.

Abstract 218: The evolutionary history of 2,658 cancers

Cancer develops through a continuous process of somatic evolution. Whole genome sequencing provides a snapshot of the tumor genome at the point of sampling, however, the data can contain information that permits the reconstruction of a tumor's evolutionary past.

Here, we apply such life history analyses on an unprecedented scale, to a set of 2,658 tumors spanning 39 cancer types. We estimated the timing of large chromosomal gains during tumor evolution, by comparing the rates of doubled to non-doubled point mutations within gained regions. Although we find that such events typically occur in the second half of clonal evolution, we also observe distinctive and early chromosomal gains in some cancer types, such as gains of chromosomes 7, 19 and 20 in glioblastoma, and isochromosome 17q in medulloblastoma. By integrating these results with the qualitative timing of individual driver mutations, we obtained an overall ranking, from early to late, of frequent somatic events per cancer type, which both identified novel patterns of tumor evolution, and incorporated additional detail into known models, such as the progression of APC-KRAS-TP53 in colorectal cancer proposed by Vogelstein and Fearon.

To estimate how mutational processes acting on the tumor genome change over time, we classified mutations in each sample according to three broad time periods (early clonal, late clonal, and subclonal), and quantified the activity of mutational signatures in each period. Most mutational processes appear to remain remarkably constant, however, certain signatures show clear and consistent changes during clonal evolution. Particularly, mutational signatures associated with exposure to carcinogens, such as smoking and UV light, tend to decrease over time. In contrast, signatures associated with defective endogenous processes, such as APOBEC mutagenesis and defective double strand break repair, show an increase between early and late phases of tumor evolution.

Making use of clock-like mutational signatures, we converted mutational time estimates for large events, such as whole genome duplication (WGD), and the emergence of the most recent common ancestor (MRCA), into real time estimates, which allowed us to combine our analyses into overall timelines of cancer evolution, per tumor type. For example, the typical timeline of ovarian adenocarcinoma development shows that early tumor evolution is characterized by mutations in TP53, and widespread genome instability, with WGD events taking place on average 8 years prior to diagnosis. In later stages of evolution, signatures of defective repair processes increase, and the MRCA emerges on average 1 year before diagnosis.

Taken together, these data reveal the common and divergent evolutionary trajectories available to a cancer, which might be crucial in understanding specific tumor biology, and in providing new opportunities for early detection and cancer prevention.

Citation Format: Clemency Jolly, Moritz Gerstung, Ignaty Leshchiner, Stefan C. Dentro, Santiago Gonzalez, Thomas J. Mitchell, Yulia Rubanova, Pavana Anur, Daniel Rosebrock, Kaixian Yu, Maxime Tarabichi, Amit Deshwar, Jeff Wintersinger, Kortine Kleinheinz, Ignacio Vásquez-García, Kerstin Haase, Subhajit Sengupta, Geoff Macintyre, Salem Malikic, Nilgun Donmez, Dimitri G. Livitz, Mark Cmero, Jonas Demeulemeester, Steve Schumacher, Yu Fan, Xiaotong Yao, Juhee Lee, Matthias Schlesner, Paul C. Boutros, David D. Bowtell, Hongtu Zhu, Gad Getz, Marcin Imielinski, Rameen Beroukhim, S Cenk Sahinalp, Yuan Ji, Martin Peifer, Florian Markowetz, Ville Mustonen, Ke Juan, Wenyi Wang, Quaid D. Morris, Paul T. Spellman, David C. Wedge, Peter Van Loo, PCAWG Evolution and Heterogeneity Working Group. The evolutionary history of 2,658 cancers [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 218.

Abstract P4-15-05: The presence of one or multiple foci of microinvasion is not associated with an increased risk of local recurrence in women with ductal carcinoma in situ treated with breast conserving therapy

Background: Ductal Carcinoma in Situ (DCIS) is a non-invasive breast cancer often treated with breast-conserving surgery (BCS) with or without radiotherapy (RT). It is unclear if the presence of microinvasion (MI) (invasion ≤1mm) is associated with an increased risk of LR (DCIS or invasive) or invasive LR compared to women with pure DCIS. In addition, the impact of multiple foci (&gt;2) of MI compared to pure DCIS is also unknown; therefore, it is unclear if some women with MI require more aggressive treatment. We evaluated the impact of the presence of MI and the number of foci of MI on the risks of any LR and invasive LR in a population of women with DCIS with and without MI treated with BCS.

Methods: The cohort includes all women diagnosed with pure DCIS or DCIS with MI in Ontario from 1994-2003 treated with BCS +/- RT. All cases had systematic pathology review to confirm the presence and number of foci of MI. Treatment and outcomes were ascertained through administrative databases and validated by chart review. Cox proportional hazards model was used to evaluate the impact of MI and the number of foci of MI (1 vs &gt;2 foci) on the development of any LR and invasive LR compared to cases with pure DCIS. The 10-yr local recurrence-free survival (LRFS) and invasive LRFS rates were calculated using the Kaplan-Meier approach with differences compared using the log-rank test.

Results: The population cohort includes 2,988 women with DCIS treated by BCS (N=2,721 pure DCIS, N= 267 DCIS with MI). Median follow-up (12 years; p=.23) and median age at diagnosis (58 years; p=.17) were similar in both groups. RT was given in 58% of cases with MI and 51% of cases with pure DCIS (p=.03). Hormonal therapy was utilized in 7.1% of women with MI and 5.3% of women with pure DCIS (p=.22). LR developed in 59 (22.1%) cases with MI and 530 (19.6%) cases of pure DCIS. Women with MI were more likely to have high nuclear grade (p&lt;.001), and larger tumor size (p&lt;.001) compared to those without MI. On multivariable analyses adjusted for age, the presence of 1 focus of MI(HR=.92, 95% CI: .64-1.33) or ≥2 foci of MI (HR=1.26, 95% CI: .85-1.85) was not associated with an increased risk of any LR compared to cases with pure DCIS. Factors associated with any LR were age &lt;50 years at diagnosis, RT, multifocality and high nuclear grade. The presence of 1 focus of MI (HR=.86, 95% CI: .52-1.40) or &gt; 2 foci of MI (HR=1.45, 95% CI: .90-2.32) was also not associated with an increased risk of invasive LR compared to cases of pure DCIS. Among women treated with BCS alone, the 10 year LRFS rates were 80%, 75% and 73% for women with pure DCIS, 1 focus, &gt;2 foci of MI (p=.10). The invasive LRFS rates were 89%, 91% and 85% (p=.26). Among women treated with BCS+RT, the 10 year LRFS rates were 87%, 88% and 80% (p=0.32) for women with pure DCIS, 1 focus or ≥2 foci of MI. The invasive LRFS rates were 93%, 90% and 86% (p=.44). There was no interaction between the presence of MI and RT.

Conclusions: Women with DCIS with one or multiple foci of microinvasion (&lt;1mm) treated by breast conserving therapy do not have an increased risk of LR or invasive LR compared to women with pure DCIS.

Citation Format: Lalani N, Paszat L, Sutradhar R, Gu S, Fong C, Nofech-Mozes S, Hanna W, Tuck A, Youngson B, Miller N, Done SJ, Chang MC, Sengupta S, Elavathil L, Jani PA, Bonin M, Rakovitch E. The presence of one or multiple foci of microinvasion is not associated with an increased risk of local recurrence in women with ductal carcinoma in situ treated with breast conserving therapy [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P4-15-05.

Abstract P4-04-10: Molecular features of dormancy in ER+ breast cancers

Background:Late recurrence (emergence from dormancy) is characteristic of ER+ breast cancers. Despite adjuvant endocrine therapy, many breast cancers recur decades after their initial diagnosis and treatment. Why this occurs is poorly understood.

Methods: We studied 2 independent datasets of endocrine treated, ER+ breast cancers with up to 20 years follow-up. The 1st comprised matched samples from the primary tumor pretreatment at diagnosis and the first recurrence after or during adjuvant endocrine therapy (all FFPE). The 2nd dataset comprised pretreatment biopsies only (all snap frozen). For both datasets, high quality RNA was amplified, labelled, and subjected to transcriptome analysis using the Affymetrix technology (U133 Plus 2.0). Low quality data were identified using 'simpleaffy' and 'ffpe', and removed; all tools were from the R package unless otherwise noted. Remaining data were normalized using 'frma'. Genes differentially expressed between early (≤3 years) and late (≥ 5 years) were selected using limma. Unsupervised hierarchical clustering and PCA explored the structure of the data.

A similar molecular analysis was done on the 2nd dataset. A classification scheme that robustly separated early from late recurrences was validated in an independent public dataset of comparable patients, array platform, and frozen tissues. We also explored features in pretreatment samples that predetermined response duration.

Results: Genes that separated pretreatment specimens by recurrence time did not separate posttreatment specimens. Specimens did not cluster in patient pairs or by site of recurrence.

8245 genes were differentially expressed between early and late recurrences in the FFPE samples, while 2400 genes were significantly different in the same comparison in the frozen samples. Initial pathway analysis was done on each dataset independently using IPA (Ingenuity® Systems, www.ingenuity.com). 70 canonical pathways were identified in common between the two datasets (pretreatment). We then looked for genes regulated in both datasets (ignores FFPE and frozen tissue as source). There were 279 genes in common that differentially regulated in the same direction (upregulated; downregulated). IPA analysis of these genes identified 49 canonical pathways. We also explored the differentially expressed gene sets using 'GSEA' (www.software.broadinstitute.org/gsea/index.jsp). Pathways consistently associated with early vs. late recurrence include integrin signaling, the unfolded protein response, endoplasmic reticulum stress, actin-based motility, and estrogen biosynthesis.

Conclusion: Analysis of pretreatment tumors can predict early recurrences from those that will remain dormant and recur much later. Recurrent tumors exhibit a remodeled molecular landscape that likely reflects the effects of treatments and/or a recreation of a niche with potentially common features at the site of recurrence. Changes in molecular signaling associated with duration of recurrence are consistent with our experimental model studies in vitro implicating UPR signaling as a major integrator of response to endocrine therapy and duration of survival. Additional data sets are being arrayed and more detailed molecular signaling studies are in progress.

Citation Format: Clarke R, Dixon MJ, Jin L, Turnbull A, Hu R, Zwart A, Wang Y, Xuan J, Sengupta S, Renshaw L, Sims A, Liu MC. Molecular features of dormancy in ER+ breast cancers [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P4-04-10.